[Primary testicular NK/T cell lymphoma. Case report and review of literature].

Natural killer/T cell lymphomas chiefly involving the midline facial structures including the nasal cavity or nasopharyns are a relatively rare type of non-Hodgkin's lymphoma. Apart from the upper respiratory tract, the disease occasionally presents in certain extranodal sites, such as the central nervous system, skin, gastrointestinal tract, or testes. We report a case of natural killer NK/T cell lymphoma as a testicular tumor in a 36-year-old man with a history of progressive swelling of his right testicle. Histologically, the testicular mass showed a diffuse infiltrate of medium-sized and atypical large lymphoid cells with angiocentric infiltration and areas of coagulative necrosis. Immunohistochemical studies demonstrated tumor cells staining positively with CD3, TIA-1, and Granzyme B. The Epstein-Barr virus genoma was detected by in situ hybridization. There were no abnormal findings in the nasal and nasopharyngeal regions. Classified as stage IEA, the patient received involved-field irradiation to contralateral testis (45 Gy), followed by systemic chemotherapy with a combination regimen ofL-asparaginase, methotrexate and dexamethasone. Relevant literature is reviewed, and the clinicopathologic features, natural history, and treatment options for primary testicular NK/T cell lymphoma are discussed.