Showing papers in "The American Journal of Surgical Pathology in 1991"

Neuroendocrine tumors of the lung with proposed criteria for large-cell neuroendocrine carcinoma. An ultrastructural, immunohistochemical, and flow cytometric study of 35 cases.

Abstract: Based on our review of 35 cases and the literature, we found the spectrum of pulmonary neuroendocrine (NE) tumors to be too broad to fit into the traditional three-category classification scheme of typical carcinoid (TC), atypical carcinoid (AC), and small-cell lung carcinoma (SCLC). We found that a spectrum of high- and low-grade tumors exist between TC and SCLC and that in the past many of these tumors have been called AC. We chose to adhere to Arrigoni's definition of AC, as his original criteria characterized a low-grade tumor. For the higher grade non-small-cell tumors (NSCLC), we propose a fourth category of large-cell neuroendocrine carcinoma (LCNEC), which is characterized by: (a) light microscopic NE appearance; (b) cells of large size, polygonal shape, low nuclear-cytoplasmic ratio (N:C), coarse nuclear chromatin, and frequent nucleoli; (c) high mitotic rate [greater than 10/10 high-power fields (HPF)] and frequent necrosis; and (d) NE features by immunohistochemistry (IHC) or electron microscopy (EM). Thus, after deciding that a pulmonary NE tumor is high grade, the major diagnostic issue is separation of LCNEC from SCLC. This distinction is based not only on cell size, but on a variety of morphologic features. We studied 20 TC, six AC, five LCNEC, and four SCLC and characterized the clinical, light microscopic, EM, IHC, and flow cytometric features of each type of tumor. We did not find any advantage to IHC, EM, or flow cytometry over light microscopy in the subclassification or prediction of prognosis; however, these methods were useful in characterizing these four types of pulmonary NE tumors and in demonstrating their NE properties. LCNEC must be distinguished from a fifth category pulmonary NE tumor: NSCLC with NE features in which NE differentiation is not evident by light microscopy and must be demonstrated by EM or IHC. Although the prognosis of LCNEC appears to be intermediate between AC and SCLC, larger numbers of patients will be needed to demonstrate significant differences in survival.

Intra-abdominal desmoplastic small round-cell tumor. Report of 19 cases of a distinctive type of high-grade polyphenotypic malignancy affecting young individuals.

Abstract: Nineteen cases of a distinctive type of malignant small-cell tumor are presented. The main features of the entity are as follows: a predilection for adolescent males (mean age: 18.6 years); predominant or exclusive intra-abdominal location, with only inconstant and secondary organ involvement; nesting pattern of growth; focal rhabdoid features; intense desmoplastic reaction; immunohistochemical reactivity for epithelial [keratin, epithelial membrane antigen (EMA)], neural [neuron-specific enolase (NSE)], and muscle (desmin) markers; and highly aggressive behavior. It is proposed that this represents yet another member of the continuously enlarging and evolving family of small round (blue) cell tumors of infancy and childhood that features, more than any other member of this group, the capacity for simultaneous multidirectional phenotypical expression.

Inflammatory fibrosarcoma of the mesentery and retroperitoneum. A tumor closely simulating inflammatory pseudotumor.

Abstract: We report 38 cases of inflammatory fibrosarcoma occurring in 23 females and 15 males, 2 months to 74 years of age (median, 8.5 years; mean, 15 years) with symptoms of abdominal pain (17 cases), anemia (21 cases), fever (14 cases), mass (16 cases), and gastrointestinal obstruction (7 cases). Primary tumor sites included mesentery and retroperitoneum (31 cases), omentum (two cases), mediastinum (two cases), liver (one case), diaphragm (one case), and abdominal wall (one case). Sizes ranged from 2.4 cm to 20 cm (mean, 9.6 cm). Follow-up data in 27 cases revealed local recurrences in 10 patients, with multiple local recurrences in three and histologically proven distant metastases to lung (two cases) and brain (one case). Five patients died from their disease (median, 20 months). All tumors, including metastases, consisted of fibroblasts, myofibroblasts, and plasma cells, with variable degrees of fibrosis and calcification. Immunostains indicate myofibroblastic differentiation; 18 of 20 (90%) stained for actin, 15 of 18 (83%) for vimentin, and 10 of 13 (77%) for keratin (primarily in a submesothelial location). Ultrastructural studies also disclosed myofibroblastic features. The locally aggressive, recurrent nature of these neoplasms, as well as the occurrence of metastases and tumor deaths, indicate that they are potentially malignant neoplasms that we believe are better classified as inflammatory fibrosarcomas, not as cellular inflammatory pseudotumors.

T-cell lymphoma involving subcutaneous tissue. A clinicopathologic entity commonly associated with hemophagocytic syndrome.

Abstract: Eight cases of T-cell lymphoma localized primarily to the subcutaneous adipose tissue are described, five of which were referred in consultation with a benign diagnosis having been made or suggested. All patients presented with 1-12-cm-diameter subcutaneous nodules, which preferentially involved the extremities in six individuals. Histologically, the lesions were reminiscent of panniculitis and were composed of a mixture of small and large atypical lymphoid cells (large cells predominated in four cases) infiltrating between adipocytes. Focally, sheets of tumor cells were found. Karyorrhexis, fat necrosis, and benign histiocytes were present in all cases. Involvement of small blood vessels was found in seven cases, but the infiltrates were not primarily angiocentric, and angiodestruction was minimal or absent. Immunophenotypic analysis (paraffin or frozen sections) in all cases showed that the atypical cells were of T-cell phenotype. Frozen-section studies demonstrated a mature T-cell phenotype with evidence of pan-T-cell antigen loss in two of five lesions. Genotypic analysis demonstrated a rearrangement of the T-cell receptor beta-chain gene in one (possibly two) biopsies of three cases studied. All patients had some evidence of hemophagocytosis during their clinical course. Six patients developed a florid hemophagocytic syndrome, fatal in five patients. Autopsies were done in all of the expired patients, and all had residual subcutaneous lymphoma and a hemophagocytic syndrome. Dissemination to nonsubcutaneous sites did not occur. Three patients are currently alive without evidence of lymphoma after aggressive chemotherapy (mean follow-up, 12 months). These results suggest that T-cell lymphomas that are primarily localized to the subcutaneous tissue may represent a distinct clinicopathologic entity. Initial biopsy findings may be misinterpreted as benign. A hemophagocytic syndrome commonly supervenes that may be secondary to lymphokine production by the malignant cells or related to the destruction of normal cells at subcutaneous sites.

Borderline epithelial lesions of the breast.

Abstract: The concept of borderline epithelial lesions of the breast remains a controversial one, both at the conceptual and practical levels. The work of Page and collaborators (17-20) has suggested the existence of a continuum between hyperplasia and carcinoma in situ, and that the risk for the development of invasive carcinoma correlates with the degree of proliferation and atypia. A small survey made among a group of five experienced surgical pathologists to test the degree of interobserver variability in this field indicates that this variability remains unacceptably high. Unfortunately, none of the special techniques that have been employed to date in an attempt to achieve a sharper and more reproducible separation between the various groups has yet fulfilled this goal. Since an element of subjectivity in the microscopic interpretation persists and is unlikely to be completely eliminated, and in view of the fact that the current terminology suggests a sharper division than what the evidence seems to indicate, consideration could be given to adopt a terminology such as mammary intraepithelial neoplasia (MIN) of either ductal or lobular types, followed by a grading system.

Surgical pathology of the lung in Wegener's granulomatosis. Review of 87 open lung biopsies from 67 patients.

Abstract: We report the pulmonary pathologic features in 87 open lung biopsies from 67 patients with Wegener's granulomatosis (WG) who were treated at a single institution from 1968 to 1990. At the time of open lung biopsy, 48 patients (72%) had classical WG with renal involvement; 19 (28%) had limited WG without renal involvement. The pathologic features were divided into major and minor manifestations. In the 82 specimens demonstrating no infectious organism, the three major pathologic manifestations of classical WG observed were also useful diagnostic criteria and included: (a) parenchymal necrosis, (b) vasculitis, and (c) granulomatous inflammation accompanied by an inflammatory infiltrate composed of a mixture of neutrophils, lymphocytes, plasma cells, histiocytes, and eosinophils. Parenchymal necrosis was found in 84% of biopsy specimens either as neutrophilic microabscesses (65% of specimens) or as large (67%) or small (69%) areas of geographic necrosis. Areas of geographic necrosis were usually surrounded by palisading histiocytes and giant cells. Additional granulomatous lesions consisted of microabscesses surrounded by giant cells (69%), poorly formed granulomas (59%), and scattered giant cells (79%). Sarcoid-like granulomas were uncommon (4%), and in only one specimen (1%) appeared within an inflammatory lesion of WG. Vascular changes were identified in 94% of biopsy specimens. Vascular inflammation was classified as chronic (37% arterial, 64% venous), acute (37% arterial, 29% venous), non-necrotizing granulomatous (22% arterial, 9% venous), and necrotizing granulomatous (22% arterial, 10% venous). Fibrinoid necrosis was relatively uncommon (11% arterial, 6% venous). Cicatricial changes were found in arteries in 41% of biopsy specimens and in veins in 16%. Capillaritis was present in 31% of specimens. Minor pathologic lesions were commonly observed in biopsy specimens associated with classical WG lesions, but they were usually inconspicuous and not useful diagnostic criteria. These included interstitial fibrosis (26%), alveolar hemorrhage (49%), tissue eosinophils (100%), organizing intraluminal fibrosis (70%), endogenous lipoid pneumonia (59%), lymphoid aggregates (37%), and a variety of bronchial/bronchiolar lesions including acute and chronic bronchiolitis (51% and 64%), follicular bronchiolitis (28%), and bronchiolitis obliterans (31%). These minor lesions were often found at the periphery of typical nodules of WG. However, in 15 specimens (18%) a minor pathologic feature represented the dominant or major finding: pulmonary fibrosis (six specimens, 7%), diffuse pulmonary hemorrhage (six specimens, 7%), lipoid pneumonia (one specimen, 1%), acute bronchopneumonia (one specimen, 1%), and chronic bronchiolitis, bronchiolitic obliterans with organizing pneumonia (BOOP), and bronchocentric granulomatosis (one specimen, 1%).(ABSTRACT TRUNCATED AT 400 WORDS)

Myoepithelial lesions of the breast. Myoepitheliosis, adenomyoepithelioma, and myoepithelial carcinoma.

Abstract: The clinical and pathologic features of 31 breast lesions composed of a prominent proliferation of myoepithelial cells either admixed with epithelial cells or in pure form were studied. The lesions were divided into three categories: myoepitheliosis, adenomyoepithelioma, and malignant myoepithelioma

Mucinous tumors of the appendix associated with mucinous tumors of the ovary and pseudomyxoma peritonei. A clinicopathological analysis of 22 cases supporting an origin in the appendix.

Abstract: Twenty-two cases in which mucinous tumors of the appendix were associated with mucinous tumors of the ovary are reported. The patients ranged from 23 to 83 (average 49) years of age and usually presented with increasing abdominal girth. The appendiceal and ovarian tumors were synchronous in 21 cases

Multilocular Thymic Cyst: An Acquired Reactive Process Study of 18 Cases

Abstract: The clinical and pathologic features in 18 cases of multilocular thymic cyst (MTC) of the anterior mediastinum unassociated with Hodgkin's disease or seminoma were studied. The majority of cases were asymptomatic and discovered incidentally on routine chest x-ray. Several patients presented with acute symptoms of chest pain or discomfort, sometimes associated with dyspnea. Two cases had an incidental thymoma, and two had an incidental thymic carcinoma. The main histologic features of MTC included the following: multiple cystic cavities partially lined by squamous, columnar, or cuboidal epithelium (some having features of Hassall's corpuscles); scattered nests and islands of non-neoplastic thymic tissue within the cyst walls, often continuous with the cyst lining; severe acute and chronic inflammation accompanied by fibrovascular proliferation, necrosis, hemorrhage, and cholesterol granuloma formation; and reactive lymphoid hyperplasia with prominent germinal centers. These features suggest that MTC most likely results from the cystic transformation of medullary duct epithelium-derived structures (including Hassall's corpuscles) induced by an acquired inflammatory process. The changes are similar to those sometimes seen in association with thymic Hodgkin's disease and thymic seminoma, which are also probably due to the inflammation that accompanies these tumors rather than to the tumors themselves. We believe that MTC is pathogenetically analogous to a variety of cystic conditions of the head and neck region, for which the common denominator seems to be the induction of cystic transformation in ductular epithelial formations of branchial pouch or related derivation by an acquired inflammatory process.

Epithelioid angiosarcoma of deep soft tissue: a distinctive tumor readily mistaken for an epithelial neoplasm.

Abstract: We report eight cases of epithelioid angiosarcoma arising in deep, usually intramuscular soft tissue. All the patients were men (mean age, 58). All the lesions arose in a limb or limb girdle. Cardinal morphologic features were the diffuse, sheetlike growth pattern, with only focally apparent vascular differentiation, and epithelioid tumor cells with a degree of intracytoplasmic vacuolation/lumen formation. Immunohistochemically, all eight cases coexpressed keratin as well as endothelial markers. In three cases, endothelial differentiation was confirmed ultrastructurally. Clinically, deep-seated epithelioid angiosarcomas are high-grade neoplasms that rapidly develop metastases. These findings expand the range of recognized epithelioid endothelial tumors and provide further evidence of keratin expression by such lesions. The presence of intracytoplasmic lumina/vacuoles (sometimes containing red blood cells) combined with the characteristic reticulin pattern and striking positivity for Factor VIII-RAg provide the clearest means of distinction from an epithelial metastasis.

Littoral cell angioma. A novel splenic vascular lesion demonstrating histiocytic differentiation.

Abstract: Seventeen cases of a novel type of vascular tumor of the spleen are described. The lesions, whose size ranges from minute foci to large nodules almost completely replacing the splenic tissue, are composed of anastomosing vascular channels resembling splenic sinus and have irregular lumina, often featuring papillary projections and cyst-like spaces; they are lined by tall endothelial cells that slough off into the vascular lumina and show hemophagocytosis. Atypical cells are absent and mitotic activity very low. In contrast to normal sinus endothelia, which express only FVIIIag, neoplastic cells express both endothelial (FVIII-AG, BMA 120) and histiocytic (KP1, lysozyme) antigens; occasionally S-100 protein is also present. The morphologic and immunohistochemical findings in this tumor reflect the dual differentiation potential of the reticuloendothelial cells lining the splenic sinus, justifying the term littoral cell angioma, and recognize a distinct entity that is different from other vascular lesions of the spleen, notably angiosarcoma. This distinction is all the more important because the clinical behaviour of this lesion is apparently benign.

Follicular colonization in B-cell lymphoma of mucosa-associated lymphoid tissue.

Abstract: The formation of neoplastic B-cell follicles is universally accepted as diagnostic of a follicle centre cell (FCC) lymphoma. Low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) are characterized by a diffuse infiltrate of cells of uncertain lineage known as "centrocyte-like" cells because of their resemblance to centrocytes (small cleaved cells). Some MALT lymphomas, however, contain numerous follicles and may even have a predominantly follicular appearance. These follicles may be reactive or show immunoglobulin (Ig) light-chain restriction, indicating their neoplastic nature. We have proposed that these neoplastic follicles are not composed of follicle centre cells but result from colonization of reactive follicles by CCL cells. In this study, the immunophenotype and genotype of 10 primary gastrointestinal lymphomas with a follicular component have been determined. One case exhibited the morphological, immunophenotypic, and genotypic features of FCC lymphoma (Ig light-chain restriction, CD10+, KB61 (CDw32)-, Jh, and bcl-2 gene rearrangement). Neoplastic follicles in the remaining nine cases, which showed the features of MALT lymphoma, were of a different phenotype (Ig light-chain restriction, CD10- KB61(CDw32)+), and these lymphomas showed Jh but not bcl-2 gene rearrangement. Taken in conjunction with the morphological features, these findings suggest that in these cases the neoplastic follicles formed as the result of colonization of previously reactive follicles by neoplastic CCL cells. Thus, not all lymphomas containing neoplastic follicles are of FCC origin. Follicular colonization, as seen in low-grade MALT lymphomas, is likely to be a recapitulation of an as yet undescribed normal immunological phenomenon that may involve marginal zone B cells.

Nodular fasciitis: Its morphologic spectrum and immunohistochemical profile

Abstract: Although nodular fasciitis (NF) is a well recognized pseudosarcomatous proliferation, it continues to cause diagnostic problems. We reviewed the clinical, histologic and immunohistochemical features of 53 lesions from 30 male and 23 female patients, ages 8-76 years, that involved the upper and lower extremities, trunk, and head and neck. Sizes ranged from 0.6 to 6.5 cm. The morphologic spectrum was broad, including the classic pattern of delicate fibroblasts suspended in a myxoid matrix, granulation tissue-like areas, solid and whorled myofibroblastic proliferations with multinucleated cells, mucoid cysts, and so-called "ancient" forms with dense, refractile strands of keloid-like collagen. Nodular fasciitis was correctly diagnosed in 23 cases (43%); a sarcoma was diagnosed in 11 (21%). A characteristic immunohistochemical profile emerged wherein 49 of 53 cases stained for smooth-muscle and muscle-specific actins, vimentin, and KP1 (a histiocyte marker), indicating dual myofibroblastic and histiocytic differentiation. None of the lesions expressed keratin, S-100 protein, or desmin. Knowledge of the immunohistochemical profile of nodular fasciitis and its overlap with certain sarcomas can decrease the likelihood of misdiagnosis.

Small-Cell Neuroendocrine Carcinoma of the Cervix: A Human Papillomavirus Type 18-Associated Cancer

Abstract: Small-cell undifferentiated carcinomas comprise a rare but aggressive subset of uterine cervical neoplasms. Analogous to small-cell anaplastic carcinoma of the lung, these tumors frequently exhibit neuroendocrine differentiation. Although human papillomaviruses (HPV) types 16 and 18 are strongly associated with the development of cervical squamous carcinoma, there is as yet little information describing the relationship of these viruses to small-cell carcinomas. To address this question, we analyzed 20 cases of small-cell carcinoma of the cervix using in situ hybridization to detect HPV gene expression. In addition, immunohistochemistry was used to evaluate three markers of neuroendocrine differentiation. Eighteen of 20 tumors (90%) demonstrated some evidence of neuroendocrine differentiation; 17 of 20 (85%) expressed HPV type 16 or 18 messenger RNA. Of the neuroendocrine-positive cases, 14 of 18 expressed HPV 18 messenger RNA. In contrast, both of the cases with squamous differentiation were HPV 16 positive. These findings broaden the spectrum of HPV-associated cervical neoplasia and strongly suggest that HPV 18 is a viral type specifically associated with cervical small-cell neuroendocrine carcinomas.

Solitary fibrous tumor of the upper respiratory tract. A report of six cases.

Abstract: We report six cases of a neoplasm that arose in the upper respiratory tract and had a histological appearance indistinguishable from that of solitary fibrous tumor of the pleura (SFT, so-called fibrous mesothelioma). The patients were adults who presented with nasal obstruction. The lesions lacked the characteristic features of other recognized neoplasms that occur in this region. The tumor cells were immunoreactive for vimentin but not for keratin. The occurrence of SFT in this location further supports the argument that SFT is a tumor of mesenchymal and not mesothelial origin. None of the tumors in this series had the histologic features of malignancy described for SFT in other locations, and there was no aggressive behavior in limited follow-up. Until more cases of SFT in unusual locations have been studied, we recommend that the same criteria used for assessing aggressiveness in SFT of the pleura be applied to them.

Solitary fibrous tumor of the nasal cavity and paranasal sinuses.

Abstract: We report two solitary fibrous tumors of the nasal cavity and paranasal sinuses that were histologically and immunohistochemically virtually identical to solitary fibrous tumors (fibrous mesotheliomas) of the pleura. One tumor arose in a 48-year-old woman and the other in a 45-year-old woman. Both patients presented with nasal symptoms, and both patients are alive without evidence of disease 6 months and 1 year after excision. The tumors had a disorganized or "patternless" arrangement of spindle cells in a collagenous background and prominent vascular channels of varying size. Immunoperoxidase stains on paraffin sections showed staining of the cells for vimentin only; there was no staining for keratin, S-100 protein, desmin, and actin. Both cases presented some degree of diagnostic difficulty and had to be distinguished from other spindle cell tumors of the nasal cavity and paranasal sinuses, such as hemangiopericytoma, angiofibroma, and fibrous histiocytoma.

Epithelioid variant of malignant peripheral nerve sheath tumor (malignant epithelioid schwannoma).

Abstract: Twenty-six cases of malignant peripheral nerve sheath tumor with a predominant epithelioid pattern were studied to determine the range of its histologic patterns, immunophenotype, and biologic behavior. The tumor presented as an asymptomatic mass either in superficial (16 cases) or in deep soft tissue (10 cases) of the extremity. Characteristically, those in deep soft tissue were composed of vague nodules of varying cellularity made up of cords or strands of rounded epithelioid cells with prominent nucleoli. Those in superficial soft tissue were uninodular masses composed of tight clusters of cells showing cell-to-cell molding but possessing the same prominence of nuclei and mitotic activity as those in deep soft tissue. Several were associated with a preexisting benign nerve sheath tumor. A number of cases deviated from the above description, including cases that resembled a clear cell carcinoma, a malignant rhabdoid tumor, and a pleomorphic sarcoma. The majority of cases (80%) strongly expressed S-100 protein and neuron-specific enolase, but all lacked a melanoma-associated antigen (as defined by HMB-45) and cytokeratin. Stains for type IV collagen defined linear immunoreactivity around single cells and groups of cells. This pattern did not differ substantially from that of melanomas and therefore did not serve as a reliable discriminant. Follow-up information indicated a more favorable course for those in superficial soft tissue compared with those in deep sites. Two of 16 patients in the former group developed metastatic disease compared with three of 10 in the latter group. Tumors in superficial soft tissue may be eminently treatable and curable, depending on size.

Prognosis and breast cancer. Recognition of lethal and favorable prognostic types.

Abstract: Assignment of breast cancer patients to specific prognostic groups has been a relatively empty exercise until the recent acceptance of the effectiveness of systemic chemotherapy. The previous question of who should be so treated has changed in North America to a question of who should not be so treated. The availability of intensive chemotherapy for the worst prognostic groups as well as efficacious, low-toxicity adjuvant chemotherapy has made prognostication mandatory. The current major question is which women with breast cancer will not benefit from chemotherapy. We are actually much better at prognostication than many studies and the current broad search for new prognostic markers would indicate. The assignment of excellent prognosis categories by defined special histologic types or grade of breast cancer as well as other measures recognize women with survival approaching or equaling the general population. Likewise, extremely poor prognosis may be recognized in 20% to 40% of women with breast cancer by the presence of extensive mitoses or high proliferation index (by any modality) and poor differentiation (highest grade). Combined tumor size and nodal status data with high-grade indicates that women with these indicators will die within 2 to 3 years with as high as 80% certainty. The surgical pathologist still determines if cancer is present and must also determine if the tumor is in situ or invasive, its type or grade if invasive, and the extent of in situ component. Considering the diminution in overall size of cancers detected by modern techniques, it is clear that validation of newer prognostic variables will be more useful and will allow more separate determinations if adapted to tissue sections rather than tissue homogenates. The many measures of these carcinomas, such as size and nodal status, make multiparametric assessment of putative prognostic markers mandatory.

Oncocytic Tumors of Major Salivary Glands: A Study of 68 Cases With Follow-up of 44 Patients

Abstract: Oncocytic tumors rarely occur in major salivary glands and generally account for less than 1% of all salivary tumors. Until now, a large series of these tumors with long-term follow-up has been lacking. We report on 68 cases of oncocytic major salivary gland tumors with clinical data on 44 patients. Eighty-four percent occurred in the parotid (male to female ratio of 1:1), and 11% arose in the submandibular gland (six males, one female). Additionally, 5% were incidentally found in salivary nests of the upper cervical lymph nodes. The mean age of all patients was 58 years. Unexpectedly, 20% of the patients had either radiotherapy to the face or upper torso or long-term occupational radiation exposure, 5-40 years prior to tumor discovery. Patients with previous radiation exposure had a mean age of 43 years at tumor discovery as compared with 63 years for all other patients (p less than 0.01). Among 44 patients, there were four definite, documented cases of recurrences: two were multiple and bilateral. A minimum 7% incidence of bilateral disease was noted. An association exists among bilateral disease, tumor recurrence, and extensive clear cell change ("clear cell oncocytosis"). Only one case metastasized: an oncocytic adenocarcinoma of the submandibular gland. None of the oncocytomas studied (including three with perineural spread) metastasized after 0.5-38 years' follow-up (mean 12 years). The literature is reviewed with regard to cases of metastasizing malignant oncocytomas.

Carcinomas of the urinary bladder simulating malignant lymphoma. A report of five cases.

Abstract: We report five carcinomas of the urinary bladder, four of them transitional cell carcinomas and one undifferentiated carcinoma, with unusual features that have received little or no comment in the literature and may be the cause of diagnostic difficulty because of their possible confusion with malignant lymphoma. Four patients were male and one female. They ranged from 61 to 76 years of age. Three tumors from these patients had a prominent (2 cases) or massive (1 case) lymphoid infiltrate that partially obscured the invasive carcinoma in two cases and largely obscured it in the third case, which closely resembled a lymphoepithelioma. The diagnosis of malignant lymphoma was only excluded with confidence in the last case after thorough immunohistochemical study. The lymphoid infiltrate was composed of numerous T-cells (UCHL-1 and Leu 22 positive) and polytypic plasma cells with admixed eosinophils; occasional germinal centers were present in one case. The tumors were deeply invasive in two patients, one of whom is alive with no evidence of disease 4 years after treatment with chemotherapy and radiation therapy; the other two cases are too recent for meaningful follow-up. Two other transitional cell carcinomas had diffuse patterns that simulated lymphoma or plasmacytoma. Recognition of these patterns of vesical carcinoma is important in order to avoid the misdiagnosis of the very rare malignant lymphoma of the urinary bladder.

Primitive polypoid granular-cell tumor and other cutaneous granular-cell neoplasms of apparent nonneural origin.

Abstract: Most cutaneous and noncutaneous granular-cell tumors are currently thought to be of Schwann-cell derivation. We present seven unusual cutaneous granular-cell lesions in which Schwann-cell origin can be excluded or is inapparent. Four of these lesions are of a previously undescribed type, and, unlike conventional granular-cell tumors of the skin, show a polypoid configuration, numerous mitoses, cytologic atypia, and a primitive immunophenotype. We propose the term "primitive polypoid granular-cell tumor" for these lesions. One occurred in a child, and three in adults. There have been no metastases to date, with follow-up periods of 2, 4, 4, and 16 years, respectively, although one tumor recurred locally. Additional cases and longer follow-up may be required to rule out the possibility that primitive polypoid granular-cell tumor is a low-grade malignancy. Two other granular-cell lesions represent variants of leiomyosarcoma, one of which widely metastasized. The last case is a granular-cell form of nodular basal-cell carcinoma. Cutaneous granular-cell neoplasms can show varying differentiation and behavior. Pathologists should not equate the occurrence of cytoplasmic granularity in a cutaneous neoplasm with the diagnosis of granular-cell schwannoma.

Clear cell tumor of the lung. Immunohistochemical and ultrastructural evidence of melanogenesis.

Abstract: Clear cell tumors of the lung (CCTL) are rare neoplasms of uncertain differentiation. A previous study of eight CCTL demonstrated a lack of epithelial features, but their exact nature remained unknown. In the current study of nine CCTL, immunohistochemistry using preliminary enzymatic digestion showed strong reactivity with the antimelanocytic markers HMB-45 (seven cases) and HMB-50 (six cases) and focal positivity for S-100 (nine cases), neuron-specific enolase (three cases), synaptophysin (one case), and Leu-7 (one case). Staining for cytokeratin, epithelial membrane antigen, chromogranin, and glial fibrillary acid protein was uniformly negative. Frozen-section immunoreactivity for vimentin and the antimelanocytic monoclonal preparation NKI/BETEB was noted in the one CCTL for which snap-frozen tissue was available. Ultrastructural examination of three glutaraldehyde-fixed CCTL showed rare neoplastic cells containing the full spectrum of melanosomes in two, one of which also contained neurosecretory-type granules. Aberrant melanosomal forms were identified in the third case. Melanosomes were not identified in the remaining five CCTL studied from formalin- or paraffin-retrieved material. The findings indicate that CCTL exhibits melanocytic differentiation. This feature may be of considerable value in distinguishing CCTL from other clear cell neoplasms.

Immunocytochemical analysis of estrogen and progesterone receptors in benign stromal lesions of the breast. Evidence for hormonal etiology in pseudoangiomatous hyperplasia of mammary stroma.

Abstract: Five cases of pseudoangiomatous hyperplasia of mammary stroma, together with seven examples of mammary hamartoma, were probed with monoclonal antibodies H222 and KD68 to investigate the possible role of estrogen and progesterone receptor expression in the pathogenesis of these benign stromal prolife

Ber-EP4 antibody as a discriminant in the differential diagnosis of malignant mesothelioma versus adenocarcinoma.

Abstract: The pathologic diagnosis of malignant mesothelioma is often difficult, even with the benefit of special studies such as histochemistry, electron microscopy, and immunohistochemistry. Ber-EP4 is a newly characterized monoclonal antibody that reliably labels epithelial tissues but does not react with mesothelial cells. We evaluated Ber-EP4 on formalin-fixed, paraffin-embedded tissue sections from 115 malignant mesotheliomas and 83 adenocarcinomas. Although 72 cases (87%) of adenocarcinoma were positive for Ber-EP4, only one (1%) of the mesotheliomas was reactive. The only adenocarcinomas that did not stain were from the breast (eight of 25 cases nonreactive) and the kidney (all three cases nonreactive). The staining pattern in the positive adenocarcinomas was usually intense and membranous, but additional weak cytoplasmic staining was seen in many cases. The reactivity was diffuse in 59 cases and focal in 13 cases. The results of our study suggest that the Ber-EP4 antibody may have great use in the differential diagnosis of mesothelioma versus adenocarcinoma, particularly when only formalin-fixed tissue is available.

Immunohistochemistry in the differential diagnosis of liver carcinomas.

Abstract: Immunohistochemical techniques were used to study 177 hepatic tumors (hepatocarcinoma, cholangiocarcinoma, hepatocholangiocarcinoma, adenocarcinoma of unknown origin, and metastatic carcinoma). Phenotypes suggestive of hepatocarcinoma included keratins 8 and 18, factor XIII a, alpha-fetoprotein. C-reactive protein, carcinoembryonic antigen (CEA) cross-reacting antigen; those in effect that excluded hepatocarcinoma were keratins 1, 5, 10, 11, 19, true CEA. C-reactive protein, used for the first time, proved to be a fairly sensitive and specific marker. Factor XIII a, which was thought to be synthesized only by histiocytes, was also present in hepatocytes. Immunohistochemistry appears to be an important tool in the diagnosis of hepatic tumors. As a result of this study, 32 cases were reclassified; several were found to be intermediate between hepatocarcinoma and cholangiocarcinoma. Sixteen cases apparently were true hepatocholangiocarcinomas. In 12 cases of hepatocarcinoma, some tumor cells expressed keratins of bile duct type. It was impossible to differentiate immunohistochemically cholangiocarcinoma from metastatic carcinoma, except in two cases with breast tissue markers.

Nasal lymphoma. A clinicopathologic study with immunophenotypic and genotypic analysis.

Abstract: We studied 13 cases of malignant lymphoma involving the nasal cavity, in six men and seven women, from 27 to 92 years of age (mean, 56 years; median, 55 years). All lymphomas had a diffuse pattern, with 10 of large-cell type (six immunoblastic polymorphous, one immunoblastic, three large cleaved cell), one of mixed small- and large-cell type and one of small cleaved-cell type. One case could not be subclassified. Angioinvasion and prominent necrosis were seen in 10 cases. Pseudoepitheliomatous hyperplasia of the overlying epithelium was present in five cases. Immunohistochemical studies on frozen or paraffin sections in nine cases revealed that the atypical cells were T cells in four cases (CD8+ in two cases) and B cells with monotypic immunoglobulin in two cases. In three cases, the findings were suggestive but not diagnostic of T lineage. Genotypic analysis in one of two cases of T-cell lymphoma revealed clonal rearrangement of the genes for beta and gamma chains of the T-cell receptor. Patients were treated initially with local radiation therapy (10 cases) or with radiation and chemotherapy (three cases). Eight patients (62%) had no relapse and were free of disease between 9 months and 23 years (mean, 6 years 5 months; median 2 years 1 month) after diagnosis. Five patients developed recurrent disease, three of whom were successfully salvaged. One patient was alive with tumor at the time of last follow-up and one died with tumor. Among cases of malignant lymphoma presenting with involvement of the nasal cavity, we find a high proportion of angioinvasive, diffuse large-cell lymphomas, with a predominance of T-cell type, and a relatively good prognosis when treated with radiation therapy.

Melanotic neuroectodermal tumor of infancy. A reexamination of a histogenetic problem based on immunohistochemical, flow cytometric, and ultrastructural study of 10 cases.

Abstract: Ten cases of melanotic neuroectodermal tumor of infancy (MNTI) were studied. There were nine males and one female ranging in age from 2 weeks to 10 months; one patient was 8 years old. Sites of origin were the maxilla (five), epididymis (two), mandible (one), skull (one), and soft tissues of the cheek (one). Six tumors recurred from 1 to 18 months after diagnosis. One patient had widespread dissemination. Electron microscopic study of four cases showed cells with melanosomes at various stages of maturation, and cells with neuroblastic features, including neurosecretory granules and cytoplasmic processes. Nine cases of MNTI were studied immunohistochemically. Small neuroblastic cells and large cells in all cases were reactive for neuron-specific enolase (NSE), synaptophysin, HMB45, and dopamine-beta-hydroxylase, large cells in all cases and few small cells were reactive for cytokeratin (CK) and vimentin (VIM). Epithelial membrane antigen was observed in large cells in three cases, four cases expressed Leu 7 antigen, three were focally positive for glial fibrillary acidic protein, one for desmin, and one for chromogranin. All cases were nonreactive for retinol-binding protein, neurofilaments, alpha-fetoprotein, S-100 protein, and carcinoembryonic antigen. Five normal adult retinas were studied similarly; the pigmented epithelium of the retina was reactive for CK, VIM, HMB45, NSE, and S-100. DNA study, performed in eight tumors, revealed aneuploidy in two (DNA index = 1.7 and 1.8); these cases recurred within 1 month. No differences were observed according to site or behavior. MNTI is a primitive neuroectodermal tumor with polyphenotypic expression of neural and epithelial markers, melanin production, occasional glial, and rhabdomyoblastic differentiation, and no photoreceptor differentiation. It probably represents a dysembryogenetic neoplasm that recapitulates the retina at 5 weeks of gestation.

Polypoid prolapsing mucosal folds in diverticular disease.

Abstract: Redundant or polypoid mucosal folds were found in eight surgically resected sigmoid colons with diverticular disease. Grossly, they were either swellings of mucosal folds or larger, leaflike, smooth-surfaced polyps with broad bases arising from mucosal folds. The number of lesions ranged from one to 11, and when multiple they formed two rows between diverticula. Swollen mucosal folds showed submucosal and mucosal vascular congestion, scanty thrombi, edema, hemorrhage, and hemosiderin deposition. Some were markedly inflamed. Polypoid lesions also showed crypt elongation and fission, upgrowth of muscle from the muscularis mucosae, and hyperplastic-metaplastic change typical of mucosal prolapse. One polyp showed evidence of an inverted diverticulum. Two cases displayed diffuse mucosal inflammation resembling inflammatory bowel disease in the region of the polyps. We speculate that these lesions result from a combination of venous congestion and mucosal redundancy secondary to spastic contraction of the muscle coat.

An immunohistochemical study of normal endometrial stroma and endometrial stromal neoplasms. Evidence for smooth muscle differentiation.

Abstract: To determine the immunohistochemical staining profile of endometrial stromal cells, we analyzed a series of formalin-fixed, paraffin-embedded normal endometrial tissues, stromal nodules, and stromal sarcomas for immunoreactivity with a panel of eight antibodies. Normal proliferative-phase (five cases) and secretory-phase (five cases) endometrial stromal cells showed the following immunopositivity: vimentin 10 of 10, muscle-specific actin (MSA) 10 of 10, alpha-smooth muscle actin (alpha sm) 10 of 10, desmin nine of 10, cytokeratin (AE1/AE3 and CAM 5.2) zero of 10, epithelial membrane antigen (EMA) zero of 10, and S-100 protein zero of 10. Antibodies to vimentin, MSA, and alpha sm stained a greater number of proliferative-phase stromal cells as compared with secretory-phase cells. Only rare stromal cells were immunoreactive for desmin, except for one case in which predecidual cells were diffusely positive. Both endometrial stromal nodules reacted with antibodies to MSA, alpha sm, and desmin, and one was vimentin positive. Each was unreactive for epithelial markers and S-100 protein. The 12 endometrial stromal sarcomas had the following immunopositivity: vimentin 11 of 12, MSA 10 of 12, alpha sm 10 of 12, desmin seven of 12, AE1/AE3 one of 12, CAM 5.2 two of 12, EMA zero of 12, and S-100 protein zero of 12. The antibodies to MSA and alpha sm usually stained a greater number of cells than did the desmin antibody. Three stromal sarcomas had sex cord-like areas, one of which exhibited focal CAM 5.2 positivity. These immunohistochemical findings for normal and neoplastic endometrial stromal cells indicate smooth muscle differentiation and are similar to those of smooth muscle neoplasms and myofibroblastic cells.

Effect of combination endocrine therapy (LHRH agonist and flutamide) on normal prostate and prostatic adenocarcinoma. A histopathologic and immunohistochemical study.

Abstract: The histopathology of 23 radical prostatectomies from patients with prostatic adenocarcinoma pretreated for 3-6 months with combination therapy including a luteinizing hormone-releasing hormone agonist and the antiandrogen drug flutamide was reviewed and compared with the pretreatment biopsies or transurethral resection material. After combination therapy, benign prostatic glands showed marked atrophy with prominent basal-cell layers, basal-cell hyperplasia, and epithelial-cell vacuolization. Immature squamous-cell metaplasia was present in seven cases. Residual carcinoma, on the other hand, was found in 19 of the 23 cases, and in 8 of these, tumor cells were either vacuolated or had scanty cytoplasm. Residual tumor was present as only one focus in 13 cases, and in 3 of these it was composed of single cells with a "hemangiopericytoma-like" pattern. An immunohistochemical study for prostatic acid phosphatase and prostatic-specific antigen could be carried out on paraffin blocks from 19 biopsies and 18 prostatectomies. After combination therapy, a reduction in staining (intensity and number of positive cells) was observed for the two markers in both normal prostate and carcinoma but with more pronounced effects on the latter. The present data show that temporary combination therapy before radical prostatectomy causes marked and very characteristic changes in normal prostatic tissue as well as in the prostatic tumor. These histologic patterns enter the differential diagnosis of a variety of atrophic, metaplastic, and proliferative lesions of the prostate gland. The pathologist must be aware of these histologic changes when looking at biopsy or resection material of treated patients.