Granuloma With an Underlying Lymphoma: A DiagnosticChallenge and a Wider Histologic Spectrum IncludingAdult T-Cell Leukemia/Lymphoma

摘要

Granuloma is defined histologically as discrete or vague nodules of epithelioid histiocytes, frequently with multi-nucleated giant cells, and is usually accompanied by small lymphocytes. Granulomatous reaction/inflammation is not uncommon in histopathology; and the underlying etiologies may include previous tissue injury, infections, drug effects, toxins, sarcoidosis, autoimmune diseases, and malignancies.1-3 In up to one third of cases, however, the causes remain idiopathic.4'5 Malignant lymphoma is one of the possible underlying causes for granuloma; and Hodgkin lymphoma (HL) is one of the common and well-studied lymphoma type associated with granuloma.4'6"9 Nonetheless, other types of B-cell or T-cell non-HL may also be associated with granulomatous inflammation, although the number of reported cases is small.10"13 Histopathologically, in lymphoma cases with a florid granulomatous reaction, the underlying neoplastic cells might be masked and overlooked, leading to a misdiagnosis. Herein, we present our experience with 7 lymphoma cases with concurrent granulomatous reaction which led to erroneous initial diagnoses in 4 patients. Detailed microscopic examination together with ancillary studies, and correlation with clinical findings are mandatory to reach a correct diagnosis. Furthermore, our cases broaden the spectrum of lymphoma entities that could be associated with a granulomatous reaction.