The American journal of surgical pathology
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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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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.