CD56+ lymphoma presenting as a testicular tumor.

A case of an unusual lymphoma type, CD56 (+) T/NK lymphoma, presenting as a testicular tumor is described. A 35 year old man who presented with right testicular swelling, underwent right inguinal orchiectomy, with a presumptive diagnosis of abscess or malignancy. Histopathology showed a diffuse mixed large and small cell lymphoma with a focal angiocentric growth pattern. Immunohistochemically CD45RO and CD56 were found to be positive in the neoplastic cells. In situ hybridization assay for EBV showed the presence of EBV related small ribonucleic acid sequences (EBER) within the tumor cells. Despite systemic chemotherapy, the patient had an aggressive clinical course with two skin and left testicular recurrences in the first year of his disease.