Typical radiologic findings of a pulmonary metastasis include multiple round variable-sized nodules and diffuse thickening of interstitium. In daily practice, however, atypical radiologic features of metastases are often encountered that make distinction of metastases from other nonmalignant pulmonary diseases difficult. A detailed knowledge of the atypical radiologic features of a pulmonary metastasis with a good understanding of the histopathologic background is essential for correct diagnosis. Squamous cell carcinoma is regarded as the most common cell type of a cavitating metastasis, but metastatic nodules from adenocarcinomas and sarcomas also cavitate occasionally. Calcification can occur in a metastatic sarcoma or adenocarcinoma, which makes differentiation from a benign granuloma or hamartoma difficult. Peritumoral hemorrhage results in areas of nodular attenuation surrounded by a halo of ground-glass opacity. Pneumothorax commonly occurs in metastases from an osteosarcoma. Air-space consolidation is often seen in cases of metastases from gastrointestinal tract malignancies. Even though tumor emboli in pulmonary arteries can be seen at computed tomography, diagnosis is difficult because they are located in small or medium arteries. A common radiologic appearance of an endobronchial metastasis is an atelectasis. In cases of an endobronchial or a solitary pulmonary metastasis, differentiation between bronchogenic carcinoma and metastasis is difficult. Dilated vascular structures within the mass can be seen in metastatic sarcomas. A sterilized metastasis after chemotherapy is radiologically indistinguishable from a residual viable tumor. Benign tumors such as uterine leiomyomas and giant cell tumors of the bone rarely metastasize to the lung.

Atypical pulmonary metastases: spectrum of radiologic findings.

UNLABELLED Chondroblastoma is an aggressive tumor of bone with the capacity for recurrence and metastasis. We sought to determine the prognostic factors that affect survival and local recurrence with particular emphasis on surgical technique and the anatomic constraints of the open physis. It was hypothesized that an open growth plate would impact the local recurrence rate negatively and be a primary determinant of treatment outcome. We retrospectively reviewed 82 consecutive patients treated at one institution. Intralesional treatment with meticulous curettage and bone graft resulted in local control in the majority of patients. Four local recurrences developed between 5 and 51 months. An open growth plate was not found to correlate with local recurrence. In most cases, the open physis did not considerably impact surgical technique. Although the median age of the patients was 16 years, the majority of patients had a closed or closing physis. Few patients had substantial growth remaining. A physeal-sparing operation was done in six patients, and no local recurrences were observed in this group. The factors that seemed to affect local recurrence included inadequate surgery and biologic aggressiveness of the tumor. Inadequate surgery was likely to be the cause of local recurrence in patients who presented after previous treatment elsewhere. Three patients who developed local recurrence manifested increased biologic aggressiveness of disease. These patients subsequently developed metastatic disease and malignant transformation of disease. All three patients died from their disease. Pelvic tumors tend to be biologically more aggressive and more apt to recur locally and metastasize to distant locations. LEVEL OF EVIDENCE Therapeutic Study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Treatment and prognosis of chondroblastoma.

The histogenesis of pulmonary sclerosing hemangioma has remained controversial despite extensive studies by many investigators. The availability of an antibody to thyroid transcription factor-1 (TTF-1), which is expressed in type II pneumocytes and Clara cells, has prompted us to readdress this issue. Sixteen cases were immunostained with a panel of antibodies including TTF-1. The patients were predominantly women with an age range of 30 to 73 years (mean, 52 yrs). All tumors were solitary. The single male patient showed regional lymph node metastases, an unusual occurrence reported only once in the literature. All cases exhibited the classic histologic features, with variegated patterns. TTF-1 expression was observed in both the surface lining cells and the pale polygonal cells. The surface lining cells were epithelial membrane antigen (EMA)+ cytokeratin+ surfactant apoprotein A+, whereas the polygonal cells were EMA+ cytokeratin- surfactant apoprotein A-. The neuroendocrine markers synaptophysin and chromogranin were both negative. The metastatic deposits in the lymph nodes comprised only polygonal cells and exhibited an EMA+ cytokeratin- surfactant apoprotein A- TTF- 1+ immunophenotype. These results suggest that pulmonary sclerosing hemangioma is an epithelial neoplasm derived from primitive respiratory epithelium or incompletely differentiated type II pneumocyte or Clara cell.

Pulmonary sclerosing hemangioma consistently expresses thyroid transcription factor-1 (TTF-1): a new clue to its histogenesis.

Benign cartilage tumours of bone are the most common benign primary bone tumours and include osteochondroma, (en)chondroma, periosteal chondroma, chondroblastoma and chondromyxoid fibroma. These neoplasms often demonstrate typical imaging features, which in conjunction with lesion location and clinical history, often allow an accurate diagnosis. The aim of this article is to review the clinical and imaging features of benign cartilage neoplasms of bone, as well as the complications of these lesions.

/pdf/the-imaging-of-cartilaginous-bone-tumours-i-benign-lesions-4b0l7t5xue.pdf

The imaging of cartilaginous bone tumours. I. Benign lesions

Chondroblastoma: varied histologic appearance, potential diagnostic pitfalls, and clinicopathologic features associated with local recurrence

BACKGROUND

Metastasis of histologically benign chondroblastoma is a rare event. The authors report a new case, 12th in the literature, wherein multiple lung metastases appeared almost simultaneously with the primary lesion in the right talus bone.



METHODS

A histologic evaluation of the primary lesion in the talus and the pulmonary metastasis was performed, and an ultrastructural study of the latter was done. Published literature on metastasizing chondroblastoma was reviewed to identify any consistency in the pattern and the outcome.



RESULTS

Metastasis of chondroblastoma is uncommon but well known. Although radiologic and histologic aggressive features have been sought, they do not necessarily correlate with the outcome.



CONCLUSIONS

Metastasis in chondroblastoma has been insufficiently stressed in the literature, unlike metastasis in giant cell tumors. The purpose of this case report is not only to document this uncommon event (the 12th case of lung metastasis) but also to emphasize that patients with chondroblastoma may have metastasis at presentation. Hence, all patients need to be evaluated regularly from the onset for possible lung metastasis so that deposits can be detected early for total resection. Cancer 1998;82:675-8. © 1998 American Cancer Society.

F.R.C.S. Praful B. Desai M.S.

Papers

Benign metastasizing chondroblastoma: a case report.