Human pathology
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Comparative Study
Alveolar soft part sarcoma and granular cell tumor: an immunohistochemical comparison study.
Although the histologic features of alveolar soft part sarcoma and granular cell tumor are typically distinctive, occasional cases show a significant morphologic overlap. Differentiating these entities is crucial because granular cell tumor is almost always benign and alveolar soft part sarcoma is invariably malignant. We evaluated a panel of immunohistochemical stains (S-100 protein, inhibin, SOX10, nestin, calretinin, and TFE3) in 13 alveolar soft part sarcomas and 11 granular cell tumors. ⋯ TFE3 was positive in 91% of granular cell tumors and all alveolar soft part sarcomas. Together with PAS-D, immunohistochemical stains for S-100 protein, inhibin, SOX10, and nestin accurately identify alveolar soft part sarcoma and granular cell tumor. Although TFE3 has been reported as a relatively specific marker for alveolar soft part sarcoma, it should be recalled that it is also expressed in most granular cell tumors.
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Most pulmonary coccidioidal infections are intraparenchymal; the pleurae are rarely involved. Pleuritis is a recognized complication of ruptured cavitary infections and occasionally occurs in other settings but has not been fully characterized. To define the clinical and histopathologic characteristics of pleural coccidioidomycosis as encountered by surgical pathologists, we reviewed the clinical history, imaging, and histology of 36 biopsy-, resection-, or autopsy-confirmed cases (with coccidioidal spherules present in pleural tissue; median age, 39 years; 22 men). ⋯ Differential diagnosis of pleural effusions should include coccidioidomycosis, particularly in endemic areas, even without significant intrapulmonary disease. Most cases of coccidioidomycotic pleuritis are encountered by pathologists after resection of ruptured cavities with decortication, but pleural-predominant infections may be biopsied for diagnostic purposes. Spherules are usually rare in pleural tissue, and liberal sampling, cultures, or serologic studies may be required to confirm the diagnosis.