Showing papers in "Archives of Pathology & Laboratory Medicine in 2006"

Gastrointestinal Stromal Tumors: Review on Morphology, Molecular Pathology, Prognosis, and Differential Diagnosis

Abstract: Context.—Gastrointestinal stromal tumors (GISTs) are specific, generally Kit (CD117)-positive, mesenchymal tumors of the gastrointestinal tract encompassing a majority of tumors previously considered gastrointestinal smooth muscle tumors. They are believed to originate from interstitial cells of Cajal or related stem cells. Objective.—To review current clinicopathologically relevant information on GIST. Data Sources.—Literature in Medline and authors' own experience. Conclusions.—GISTs usually occur in older adults (median age 55–60 years) and rarely in children in the second decade (<1%) throughout the gastrointestinal tract: 60% in stomach, 35% in small intestine, and less than 5% in rectum, esophagus, omentum, and mesentery; most GISTs in the latter 2 sites are metastatic. Five percent of GISTs occur in patients with neurofibromatosis type 1 syndrome (multiple small intestinal tumors) and in Carney triad (gastric epithelioid GISTs in young females). Familial GISTs occur in patients with inheri...

Grading of soft tissue sarcomas: review and update.

Abstract: Context.—Histologic grading is the most important prognostic factor and the best indicator of metastatic risk in adult soft tissue sarcomas. The most commonly used systems are the French grading and the National Cancer Institute grading. Both are 3-grade systems and are mainly based on histologic type and subtype, tumor necrosis, and mitotic activity. Rules for using grading should be strictly respected and limitations of grading should be known to obtain the best performance. The most controversial point is the respective values of histologic typing and grading. Histologic typing should be clearly defined before any attempt at grading, and grading should not be used on tumors of intermediate malignancy such as atypical fibroxanthoma and on some sarcomas such as dedifferentiated liposarcoma. However, grading is useful in more than 90% of adult soft tissue sarcomas and has been adapted to pediatric nonrhabdomyosarcomatous sarcomas. Current grading is not suitable for core needle biopsies. Objectiv...

Rhabdomyosarcomas in adults and children: an update.

Abstract: Context.—Rhabdomyosarcomas comprise a relatively common diagnostic entity among childhood cancers and a relatively rare one among adult tumors. They may possess a variety of histologies that generally differ among age groups. These lesions appear to be separate biologic entities as well as morphologic categories, with embryonal tumors having genetic lesions related to loss of heterozygosity and aberrant parental imprinting, alveolar tumors containing genetic fusions between PAX and forkhead genes, and pleomorphic tumors showing an accumulation of genetic lesions similar to other adult high-grade sarcomas. Objective.—To present guidelines for diagnosis of rhabdomyosarcoma and recent finding concerning the biology and classification of these lesions. Data Sources.—Review of recent and older published literature and distillation of the authors' experience. Conclusions.—Infants and young children tend to have embryonal rhabdomyosarcomas, adolescents and young adults tend to have alveolar rhabdomyosar...

Immunohistochemistry and quantitative analysis of protein expression.

Abstract: Context.—Immunohistochemistry has taken a central role in the field of pathology, and its role is destined to increase as companion diagnostics analogous to the HercepTest are required for new targeted therapeutics. However, the inherent subjectivity of the assessment of an objective value (the in situ protein concentration) suggests that new technologies to measure the protein concentration may be required to achieve the accuracy required for companion diagnostics. Objective.—This article discusses the state of immunohistochemistry and reviews the currently available devices for quantitative in situ assessment of protein expression. Data Sources.—Data for this work were collected from the published literature, the Internet, and from information provided by device vendors. Conclusions.—Although there is a long history of efforts to quantify immunohistochemistry, there has been a lack of broad acceptance because the resultant objective accuracy has not significantly improved outcome measures compa...

Molecular Classification of Human Cancers Using a 92‐Gene Real-Time Quantitative Polymerase Chain Reaction Assay

Abstract: Context.—Correct diagnosis of the tissue origin of a metastatic cancer is the first step in disease management, but it is frequently difficult using standard pathologic methods. Microarray-based gene expression profiling has shown great promise as a new tool to address this challenge. Objective.—Adoption of microarray technologies in the clinic remains limited. We aimed to bridge this technological gap by developing a real-time quantitative polymerase chain reaction (RT-PCR) assay. Design.—We constructed a microarray database of 466 frozen and 112 formalin-fixed, paraffin-embedded (FFPE) samples of both primary and metastatic tumors, measuring expression of 22 000 genes. From the microarray database, we used a genetic algorithm to search for gene combinations optimal for multitumor classification. A 92-gene RT-PCR assay was then designed and used to generate a database for 481 frozen and 119 FFPE tumor samples. Results.—The microarray-based K-nearest neighbor classifier demonstrated 84% accuracy ...

An in-depth look at Krukenberg tumor: an overview

Abstract: Krukenberg tumor is an uncommon metastatic tumor of the ovary. This article provides an overview of the major pathologic manifestations of Krukenberg tumor, patient characteristics, clinical and laboratory features of the disease, prognostic factors, and current knowledge about its pathogenesis. Pathologists have to be familiar with the diagnostic histopathologic features of the tumor and its principal differential diagnoses. Awareness of the diagnostic manifestations of the tumor leads to the correct diagnosis and prevents tumor misclassification, thus avoiding improper clinical management. The article also addresses the potential clinical utility of serum CA 125 in patients with Krukenberg tumors. Prognosis of Krukenberg tumor is still very poor but our review of the literature reveals several factors that appear to have an impact on survival. There is no established treatment for Krukenberg tumors. A national registry and prospective studies are needed to set a therapeutic approach for Krukenberg tumors in the hope of improving the survival rate.

Intraepithelial Lymphocytosis in Architecturally Preserved Proximal Small Intestinal Mucosa: An Increasing Diagnostic Problem With a Wide Differential Diagnosis

Abstract: Context.—An increased intraepithelial lymphocyte density in an architecturally normal proximal small intestinal mucosal biopsy is a common finding facing surgical pathologists dealing with gastrointestinal biopsy specimens. Approximately 1% to 2% of all proximal small intestinal biopsies will show this change. It is increasingly recognized by surgical pathologists that gluten-sensitive enteropathy is an important cause of this pattern; however, gluten-sensitive enteropathy accounts for the minority of all cases. A wide variety of immunologic stimuli can raise intraepithelial lymphocyte numbers. Among the other common associations are enteric infection, autoimmune disease, drugs, and gastric Helicobacter infection. Objective.—To outline the causes of intraepithelial lymphocytosis, to highlight the importance and the difficulties faced in establishing gluten-sensitive enteropathy as the cause, and to aid the surgical pathologist in the routine sign out of these cases. Data Sources.—A review of the ...

9-color and 10-color flow cytometry in the clinical laboratory.

Abstract: Context.—The development of commercial flow cytometers capable of detecting more than 10 simultaneous fluorescent signals presents opportunities for improved diagnosis and monitoring of patients with leukemia and lymphoma. Objective.—To describe instrument and reagent characteristics necessary for successful 9-color and 10-color flow cytometry in a clinical setting. Design.—Systematic review of issues related to instrument settings, reagent performance, and general principles of panel construction. Results.—Nine-color and 10-color flow cytometry offers the possibility for increased accuracy in population identification, the ability to obtain detailed information from paucicellular specimens, improved laboratory efficiency, and the means to consistently detect abnormal populations at low levels. Careful attention to details of instrument and reagent performance allows for the development of panels suitable for screening of samples for leukemia and lymphoma in a clinical setting. Conclusions.—The c...

Identification Errors Involving Clinical Laboratories: A College of American Pathologists Q-Probes Study of Patient and Specimen Identification Errors at 120 Institutions

Abstract: ● Context.—Misidentified laboratory specimens may cause patient injury, but their frequency in general laboratory practice is unknown. Objectives.—To determine (1) the frequency of identification errors detected before and after result verification, (2) the frequency of adverse patient events due to specimen misidentification, and (3) factors associated with lower error rates and better detection of errors. Design.—One hundred twenty clinical laboratories provided information about identification errors during 5 weeks. Results.—In aggregate, 85% of errors were detected before results were released; one quarter of laboratories identified more than 95% of errors before result verification. The overall rate of patient identification errors involving released results was 55 errors per 1000000 billable tests. A total of 345 adverse events were reported. Most of the adverse events caused material inconvenience to the patients but did not result in any permanent harm. On average, adverse events resulted from 1 of every 18 identification errors. Extrapolating the adverse event rate observed in this study to all United States hospital-based laboratories suggests that more than 160000 adverse events per year result from misidentification of patients’ laboratory specimens. Conclusions.—Identification errors are common in laboratory medicine, but most are detected before results are released, and only a fraction are associated with adverse patient events. Even when taking into consideration the design of this study, which used imperfect case finding, institutions that did a better job of detecting errors within the laboratory released a smaller proportion of results that involved specimen misidentification. (Arch Pathol Lab Med. 2006;130:1106‐1113)

Neutrophil CD64 Is an Improved Indicator of Infection or Sepsis in Emergency Department Patients

Abstract: Context.—Sepsis, affecting millions of individuals annually with an associated high mortality rate, is among the top 10 causes of death. In addition, improvements in diagnostic tests for d...

The variability of results between point-of-care testing glucose meters and the central laboratory analyzer

Abstract: Context.—Point-of-care testing glucose meters are strongly recommended in the management of diabetes and are increasingly being used for making therapeutically important decisions. Thus, i...

Multiorgan Involvement in Nephrogenic Fibrosing Dermopathy: An Autopsy Case and Review of the Literature

Abstract: Nephrogenic fibrosing dermopathy is a recently recognized, scleromyxedema-like fibrosing skin condition that occurs in individuals with acute or chronic renal failure. Although the early descriptions of this disorder describe a purely cutaneous disease process, 2 recent autopsy reports have identified apparent multiorgan fibrosis with involvement of skeletal muscle, myocardium, lungs, kidneys, and testes. We describe a 23-year-old man with nephrogenic fibrosing dermopathy and significant fibrosis of the atrial myocardium and dura mater, which was identified at autopsy. Dural fibrosis is a previously undescribed systemic manifestation of nephrogenic fibrosing dermopathy. The literature is reviewed.

Malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation (malignant triton tumor).

Abstract: Malignant peripheral nerve sheath tumors arise from Schwann cells or within existing neurofibromas and have a strong association with type 1 neurofibromatosis. These tumors are histologically diverse and may contain malignant areas of divergent mesenchymal differentiation, the most common of which is skeletal muscle (rhabdomyosarcoma). Malignant peripheral nerve sheath tumor with rhabdomyosarcomatous differentiation is also known as malignant triton tumor. Malignant triton tumor has a worse prognosis than classic malignant peripheral nerve sheath tumor does, and the correct diagnosis requires attention to the clinical history and knowledge of the complexities regarding its differential diagnosis. In this review we discuss the clinical, histopathological, immunohistochemical, and prognostic features of this rare neoplasm.

Renal failure and nephrocalcinosis associated with oral sodium phosphate bowel cleansing: clinical patterns and renal biopsy findings.

Abstract: Acute renal failure (ARF) is rarely reported after bowel preparation with sodium phosphate. We report a patient with mild Crohn disease (in remission), without history of renal disease, and with normal baseline renal function, who developed ARF 14 days after bowel preparation for colonoscopy with oral sodium phosphate. A renal biopsy showed multifocal calcium phosphate deposition in the renal tubules against a background of diffuse chronic tubulointerstitial injury. Review of the literature suggested 2 distinct patterns of ARF in the context of sodium phosphate bowel cleansing. One pattern is characterized by ARF, which develops a few hours or days after sodium phosphate administration, as a component of a systemic syndrome associated with severe hyperphosphatemia and hypocalcemia. Correction of these electrolyte abnormalities was frequently associated with rapid recovery of renal function. The cause of ARF in this context was not clear because the favorable outcome negated the need for renal biopsy. In the second pattern, exemplified by the current patient, ARF was identified incidentally. These patients did not have any features of an acute syndrome immediately after sodium phosphate administration and presented much later (usually weeks) with mild, nonspecific symptoms. At the time of presentation, the serum calcium and phosphate levels were normal. The renal biopsies in each of these patients showed nephrocalcinosis as the possible cause of ARF. The renal failure improved at least partially in most of these patients, but persisted in rare cases.

Birt-Hogg-Dubé Syndrome: Clinicopathologic Findings and Genetic Alterations

Abstract: Context.—Birt-Hogg-Dube (BHD) syndrome is a rare clinicopathologic condition transmitted in an autosomal dominant fashion. This complex entity is characterized by cutaneous fibrofolliculomas, kidney tumors, pulmonary cysts, and spontaneous pneumothorax. Recently, the gene possibly responsible for the clinical manifestations of BHD syndrome has been cloned and characterized. The few reviews of BHD syndrome found in the English literature mostly focus on the skin lesions or genetics, with limited information on other pathologic changes, particularly the kidney lesions. Objective.—To review the literature on this subject with a special emphasis on BHD syndrome-associated renal pathology as well as recent advances in molecular genetic discovery of the BHD syndrome. Data Sources.—We used all data available after performing a literature search using MEDLINE and searching under the headings “Birt-Hogg-Dube,” “hybrid oncocytic tumors,” and “folliculin.” Conclusions.—The presence of BHD syndrome should be...

Thyroid tumors with a follicular growth pattern: problems in differential diagnosis.

Abstract: Tumors of the thyroid characterized by a follicular growth pattern constitute the most common type of lesion of this organ encountered by pathologists. The vast majority of such lesions do not pose difficulties for histopathologic interpretation. A subset of these tumors, however, can represent a serious challenge for diagnosis. Thyroid tumors with a follicular growth pattern include a broad range of lesions that range from benign, hyperplastic nodules to follicular adenomas to follicular carcinomas. In addition, other types of tumors belonging in separate diagnostic categories can also present histologically with a follicular growth pattern, including the follicular variant of papillary thyroid carcinoma and medullary carcinoma. The histologic features and diagnostic criteria used for distinguishing among these conditions can often be subtle and subjective.

Malignant neoplasm of perivascular epithelioid cells of the liver.

Abstract: Neoplasms of perivascular epithelioid cells (PEComas) have in common the coexpression of muscle and melanocytic immunohistochemical markers. Although this group includes entities with distinct clinical features, such as angiomyolipoma, clear cell sugar tumor of the lung, and lymphangioleiomyomatosis, similar tumors have been documented in an increasing diversity of locations. The term PEComa is now generally used in reference to these lesions that are not angiomyolipomas, clear cell sugar tumors, or lymphangioleiomyomatoses. While most reported PEComas have behaved in a benign fashion, malignant PEComas have occasionally been documented. We present a case of hepatic PEComa with benign histologic features, which nonetheless presented with metastases to multiple sites nearly 9 years later. This case represents the second documented malignant PEComa of the liver, as well as the longest follow-up of a surviving patient with a malignant PEComa, emphasizing both the need for criteria that more accurately predict the behavior of PEComas and the necessity of long-term follow-up of patients with PEComas.

Desmoplastic small round cell tumors: cytologic, histologic, and immunohistochemical features.

Abstract: Desmoplastic small round cell tumor (DSRCT) is a recently recognized clinicopathologic entity that has a predilection for adolescent males and usually affects the abdominal cavity. Due to its uncommon nature, many pathologists lack experience with this tumor. The literature regarding DSRCT is reviewed with special attention to its histologic and cytologic diagnosis. Morphologic features of DSRCT and its immunohistochemical and cytogenetic profile are summarized and differential diagnosis with other small round cell tumors is discussed. As observed by both histologic and cytologic examinations, small round blue cells and fibrosclerotic stroma are the striking morphologic features of DSRCT. The typical immunohistochemical profile is characterized by coexpression of epithelial, mesenchymal, myogenic, and neural markers. Cytogenetically, this tumor harbors a specific karyotypic abnormality, namely t(11;22)(p13;q12). These features distinguish DSRCT from other members of the family of small round cell tumors.

Mastocytic enterocolitis: increased mucosal mast cells in chronic intractable diarrhea.

Abstract: Context.—In some adult patients with chronic intractable diarrhea, the diagnosis remains elusive even after detailed evaluations, and colonic or duodenal biopsy specimens may appear unremarkable on routine hematoxylin-eosin staining. Objectives.—To assess the concentration of mast cells in colonic or duodenal biopsy specimens by immunohistochemical analysis for mast cell tryptase from patients with chronic intractable diarrhea and to evaluate their response to drugs affecting mast cell function. Design.—Mast cells per high-power field were assessed in biopsy specimens from 47 patients with chronic intractable diarrhea, from 50 control subjects, and from 63 patients with other specific diseases that cause chronic diarrhea (inflammatory bowel disease, celiac disease, collagenous colitis, and lymphocytic colitis). Patients with chronic intractable diarrhea who had more than 20 mast cells per high-power field were administered drugs affecting mast cell mediator function and release. Results.—The mean...

The application of molecular techniques to the study of hospital infection

Abstract: Context Nosocomial infections represent an important cause of morbidity and mortality in hospital settings, resulting in high health care costs. The roles of an epidemic investigation are to recognize that a problem exists, to compare characteristics of affected persons with those of similar but unaffected persons (case-control study), and to identify risk factors. Integrating typing methods as part of conventional epidemiologic surveillance is cost-effective and results in a reduction in rates of nosocomial infections. During the past 10 years, there has been unprecedented progress in molecular biology and in the application of nucleic acid technology to the study of the epidemiology of human infections. Objectives To summarize the available molecular tests for determination of the relatedness of microorganisms causing nosocomial infections, emphasizing the most useful applications of the tests to the study of the epidemiology of hospital-acquired infection; and to discuss the appropriate use of these tests in the prevention and control of hospital-associated infection. Data source Published English-language literature from 1980 to the present. Conclusions Pulsed-field gel electrophoresis is the method of choice for strain delineation. The newest techniques include polymerase chain reaction and multilocus sequence typing, in which various housekeeping genes that are stable markers of strain identity are sequenced. Molecular techniques are broadly applicable to the study of diverse pathogens. Typing data obtained by DNA analysis should always be considered together with epidemiologic information, because only this combination will enable the most accurate epidemiologic evaluation.

Meckel-gruber syndrome : Pathologic manifestations, minimal diagnostic criteria, and differential diagnosis

Abstract: This article provides an overview of the major pathologic manifestations of Meckel-Gruber syndrome, current knowledge about its pathogenesis, minimal diagnostic criteria, and differential diagnosis. Typical sonographic findings (occipital encephalocele, postaxial polydactyly, and cystic enlargement of the kidneys) allow for diagnosis of most cases before the 14th week of gestation, but the pathologist may encounter clinically unsuspected or atypical cases that require morphologic confirmation. In these cases, a meticulous autopsy is necessary to establish the diagnosis of Meckel-Gruber syndrome.

Elder maltreatment: a review.

Abstract: Context.—Elder maltreatment is not a new entity but is one that is recently recognized as a widespread and growing social problem. Unfortunately, few physicians are trained to recognize the different forms of elder maltreatment including physical abuse, sexual abuse, and neglect. The elder, age 65 years or older, is also a unique individual with respect to pathophysiology. The natural changes of aging must be considered when assessing any physical or laboratory findings. Objective.—The practicing pathologist and resident/fellow in training must be familiar with the 6 forms of elder abuse, in particular the 3 forms that are seen in general and forensic pathology: physical abuse, sexual abuse, and neglect. Naturally occurring conditions must also be recognized so that these are not erroneously interpreted as trauma or neglect. Furthermore, the victims and perpetrators, scenarios and risk factors, common anatomic and clinical findings, the pathophysiology of aging, and possible imitators of abuse mu...

Key issues in handling and reporting radical prostatectomy specimens.

Abstract: Context.—Patients with prostatic adenocarcinoma commonly undergo radical prostatectomy, and it is often difficult and time consuming to handle the resulting specimens and to report the findings. Pathologic information derived from the radical prostatectomy specimen is used for selecting adjuvant therapy, such as radiotherapy and hormone therapy, and for determining a patient's prognosis. The prostate specimen must be handled in a systematic fashion to derive the appropriate prognostic parameters. Objective.—To review the prognostic factors of relevance in classifying radical prostatectomy specimens, using the College of American Pathologists categorization system, including a detailed survey of the morphologic-based factors but excluding other factors such as DNA ploidy and novel phenotypic and genotypic markers. Conclusions.—Gleason score, pathologic stage, and margin status are considered category 1 prognostic factors, which are of proven prognostic significance and are useful in patient manage...

Medicolegal aspects of error in pathology.

Abstract: Objective.—To discuss the various ways error is defined in surgical pathology. To identify errors in pathology practice identified by an analysis of pathology malpractice claims. Design.—Three hundred seventy-eight pathology malpractice claims were reviewed. Nuisance claims and autopsy claims were excluded; 335 pathology claims remained and were analyzed to identify repetitive patterns of specimen type and diagnostic category. Setting.—All pathology malpractice claims reported to The Doctors Company of Napa, Calif, between 1998 and 2003. Results.—Fifty-seven percent of malpractice claims involved just 5 categories of specimen type and/or diagnostic error, namely, breast specimens, melanoma, cervical Papanicolaou tests, gynecologic specimens, and system (operational) errors. Sixty-three percent of claims involved failure to diagnose cancer, resulting in delay in diagnosis or inappropriate treatment. Conclusion.—A false-negative diagnosis of melanoma was the single most common reason for filing a m...

Patient Safety in the Clinical Laboratory: A Longitudinal Analysis of Specimen Identification Errors

Abstract: Context.—Patient safety is an increasingly visible and important mission for clinical laboratories. Attention to improving processes related to patient identification and specimen labeling is being paid by accreditation and regulatory organizations because errors in these areas that jeopardize patient safety are common and avoidable through improvement in the total testing process. Objective.—To assess patient identification and specimen labeling improvement after multiple implementation projects using longitudinal statistical tools. Design.—Specimen errors were categorized by a multidisciplinary health care team. Patient identification errors were grouped into 3 categories: (1) specimen/requisition mismatch, (2) unlabeled specimens, and (3) mislabeled specimens. Specimens with these types of identification errors were compared preimplementation and postimplementation for 3 patient safety projects: (1) reorganization of phlebotomy (4 months); (2) introduction of an electronic event reporting syst...

Key issues in reporting common cancer specimens: Problems in pathologic staging of colon cancer

Abstract: Context—Standardized pathologic assessment is a quality measure for cancer care Objective—Pathologic staging parameters and the clinically important stage-independent pathologic factors that pathologists find most problematic to evaluate in colorectal cancer resection specimens are reviewed The objective of this review is to provide practical guidance for the practicing surgical pathologist Data Sources—Published literature related to the TNM staging system for colorectal cancer of the American Joint Committee on Cancer and the International Union Against Cancer and to stage-independent tissue-based prognostic factor evaluation was included in the review Study Selection, Data Extraction, and Synthesis—Published guidelines from authoritative sources and published peer-reviewed data related to colorectal cancer staging and pathologic prognostic factor assessment were included for consideration The general and site-specific rules of application of the American Joint Committee on Cancer and

Molecular diagnosis of sarcomas: chromosomal translocations in sarcomas.

Abstract: Context.—Sarcomas are rare, numerous in type, and often difficult to definitively classify. Work in the last 2 decades has revealed that a significant subset of sarcomas are associated with specific chromosomal translocations producing chimeric (fusion) genes that play a role in the sarcomas' biology and are helpful in their differential diagnosis. Objective.—To briefly review the sarcomas associated with specific translocations presenting Ewing sarcoma and synovial sarcoma as archetypes and to further explain how cytogenetic and molecular biologic approaches are being used in the diagnosis of sarcomas. Data Sources.—This work is based on a selected review of the relevant medical and scientific literature and our extensive experience with molecular testing in sarcomas. Conclusions.—In addition to, and complementing, the traditional diagnostic methods of examination of hematoxylin-eosin stained slides, immunohistochemistry, and sound clinical-pathologic correlation, additional cytogenetic and mole...

Odontogenic Myxoma: A Clinicopathologic Study of 25 Cases

Abstract: Context.—Odontogenic myxoma is an uncommon tumor that has the potential for extensive destruction of the jaws. Objective.—To document the clinical, pathologic, and behavioral features of odontogenic myxomas. Design.—Histologic and immunocytochemical examinations were performed on odontogenic myxomas from 25 Chinese patients. Clinical and available follow-up data were analyzed. Results.—In the present series, 13 were male and 12 female. The age at diagnosis ranged from 6 to 66 years, with a mean age of 28.8 years. Twelve tumors involved the mandible and 13 occurred in the maxilla, with a predilection for posterior areas. The posterior maxillary tumors frequently (9/10) involved the maxillary sinus. Of the 23 cases with radiographic records, 22 lesions presented with a multilocular appearance. Although 80% of the mandibular lesions showed a well-defined border, only 33.3% of the maxillary tumors were well-defined. Histologically, odontogenic myxomas were mainly composed of spindled or stellate-shap...

Papillary thyroid carcinoma: an overview.

Abstract: Papillary carcinoma is the most common malignant tumor of the thyroid. It has a variable macroscopic appearance that differs according to the variant microscopic morphologies and the presence or absence of degenerative changes. The histologic variants can be challenging to the pathologist, and some are of clinical significance because of prognostic implications. In this short review, we discuss an approach to papillary carcinoma, the diagnostic dilemmas and controversies, and the ancillary studies that are helpful in resolving them, including immunohistochemistry and molecular studies.

Asthma: pathology and pathophysiology.

Abstract: Context.—Asthma has been defined as a chronic inflammatory disorder of the airways that is associated with recruitment of inflammatory cells and the clinical development of wheezing, shortness of breath, chest tightness, and cough. Asthma is a major public health issue. It affects 5% of the United States population and accounts for 2 million emergency department visits, 470 000 hospitalizations, and 4500 deaths annually. Objective.—To review the pathophysiology and characteristic pathologic patterns of this disease and discuss the possible mechanisms of production of the lesions. Data Sources.—We searched the literature using MEDLINE and OVID. We also searched related conference abstracts and bibliographies of selected studies. Conclusions.—There has been a significant evolution in our understanding of asthma. Specific pathways and mechanisms in recent years have been studied; however, numerous mediators and cell receptors have raised new questions that remain to be answered.