The American journal of surgical pathology
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Am. J. Surg. Pathol. · Oct 2003
Crooke's cell adenoma of the pituitary: an aggressive variant of corticotroph adenoma.
Cushing's disease is caused by functional corticotroph adenomas of the pituitary, mostly noninvasive microadenomas. Classic Crooke's cells are nonneoplastic corticotrophs with cytoplasmic accumulation of cytokeratin filaments in response to glucocorticoid excess. Corticotroph adenomas exhibiting Crooke's change are rare and incompletely understood. ⋯ Most are functional adenomas occurring in middle-aged women and are invasive macroadenomas prone to recurrence. Morbidity and mortality rates are substantial. CCAs represent a distinct entity that should be separated from corticotroph adenomas without Crooke's hyaline change.
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Am. J. Surg. Pathol. · Aug 2003
Inhibin alpha distinguishes hemangioblastoma from clear cell renal cell carcinoma.
Inhibin alpha subunit (inhibin A) expression in hemangioblastomas has not been previously reported in the literature. We analyzed the expression of inhibin A in 25 hemangioblastomas from 22 patients. Eleven cases were from 8 patients with von Hippel-Lindau disease, and these tumors were multicentric and/or recurrent. ⋯ There was no difference in the inhibin A staining pattern between the sporadic hemangioblastoma and those associated with VHL. These findings demonstrate inhibin A to be a useful marker in distinguishing hemangioblastoma from metastatic clear cell renal cell carcinoma. While the diagnostic importance is evident, the pathophysiology of inhibin A expression by the stromal cells of hemangioblastoma remains unknown and further investigation is required.
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Am. J. Surg. Pathol. · Aug 2003
Waldenstrom macroglobulinemia involving extramedullary sites: morphologic and immunophenotypic findings in 44 patients.
Waldenstrom macroglobulinemia (WM) is a clinicopathologic syndrome in which a B-cell neoplasm involving the bone marrow, usually lymphoplasmacytic lymphoma (LPL), is associated with immunoglobulin M paraprotein in the serum. Extramedullary involvement occurs in a subset of patients and is infrequently examined histologically. The files of M. ⋯ Waldenstrom macroglobulinemia is most commonly associated with LPL but can rarely occur with other types of B-cell lymphoma. Lymphoplasmacytic lymphoma in patients with WM is morphologically heterogeneous and can be indistinguishable from marginal zone B-cell lymphoma. CD5+ B-cell lymphomas with features otherwise typical of LPL are rare, and we think these tumors are part of the spectrum of LPL.
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Neuroendocrine carcinomas of the pancreas are rare neoplasms whose morphologic features generally mirror those seen in neuroendocrine tumors in other organs. Rarely, however, they may display unusual morphologic appearances that can introduce difficulties for diagnosis. We report four cases of primary neuroendocrine carcinomas of the pancreas (islet cell tumors) that were characterized by prominent "rhabdoid" features of the tumor cells. ⋯ In all cases, the rhabdoid elements appeared to merge with areas showing a more conventional neuroendocrine morphology. Immunohistochemical studies in all cases showed strong cytoplasmic positivity of the rhabdoid tumor cells for chromogranin, synaptophysin, and cytokeratin. Recognition of this unusual morphologic appearance is of importance to avoid mistaking these lesions for other types of malignant neoplasm.
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Am. J. Surg. Pathol. · Mar 2003
Invasive mammary carcinoma after immediate and short-term follow-up for lobular neoplasia on core biopsy.
Lobular neoplasia (LN), including atypical lobular hyperplasia (ALH) and lobular carcinoma in situ, may be encountered in breast core biopsies performed for mammographic abnormalities even though LN is often not, in itself, responsible for the abnormal mammogram. The need for surgical excision following a diagnosis of LN on core biopsy is not well defined. We examined pathologic and mammographic findings in a consecutive series of cases diagnosed as LN to address this issue. ⋯ The bilaterality of cancer risk was expected; however, the number of invasive carcinomas was not. That the invasive carcinomas detected at follow-up were small implies that they might have been present (but occult) at initial presentation. We conclude that lobular carcinoma in situ detected on core biopsy is potentially a significant marker for concurrent and near-term breast pathology requiring complete intensive multidisciplinary clinical follow-up with specific individualization of patient care.