Anaplastic Large Cell Lymphoma Mimicking a Necrotizing Granulomatous Lesion: A Case Report

Introduction: Epithelioid cell granulomas into neoplastic tissues have been reported in association with a wide series of neoplasms, including lymphomas. Epithelioid granulomas in association with non-Hodgkin's lymphomas are only rarely observed. When granulomas are present in association with lymphomas, they are usually non necrotizing, sarcoid-like. Little is known about the association of granulomatous reaction with anaplastic large cell lymphoma (ALCL) and to the best of our knowledge anaplastic large-cell lymphoma with histological features of necrotizing granulomatous lesion has not been reported previously in the literature. In this article we report a case of anaplastic large-cell lymphoma mimicking a necrotizing granulomatous lymphadenitis. Case Presentation Section: A 55-year-old Caucasian man presented with a 3-month history of a painless, enlarged, lymph node localized on the left inguinal region. Escissional biopsy was performed. The microscopic examination led to the diagnosis of granulomatous lymphadenitis with necrosis. Two months later the patient returned because he had note the appearance of a nodule in the right axillary region. Following the escissional biopsy, the histological examination and the immunohistochemical stains have been made the diagnosis of ALCL, ALK1 negative. The first case was revaluated. Extensive immunophenotypic characterization (positivity for CD45RO/UCHL1 and CD-30 in the areas of necrosis), in conjunction with histomorphologic and molecular analysis (presence of a T monoclonal cell lymphoid), established diagnosis of ALCL ALK-1 negative. Conclusions: The presence of exaggerated granulomatous reaction in tissue involved by lymphomas may mask neoplastic lymphoid cells and result in erroneous histopathologic diagnosis. In this article we report a case of primary nodal ALCL mimicking a necrotizing granulomatous lymphadenitis.