Extranodal nasal type natural killer/T-cell lymphoma of testis: report of seven cases with review of literature.

Seven cases of testicular extranodal natural killer (NK)/T-cell lymphoma, nasal type, are reported, with a literature review. Two patients had a testicular lesion as the initial presentation, four had a history of nasal NK/T-cell lymphoma and the remaining patient had concomitant involvement of an adrenal gland. All patients underwent orchiectomy followed by chemotherapy (CT) and/or radiotherapy (RT). Follow-up data showed that two patients with non-primary tumors died of disease within 6 and 11 months, respectively. Histologically, the tumor had a diffuse growth pattern largely replacing the interstitial tissues. Neoplastic cells showed prominent angiocentric and angioinvasive features with focal coagulative necrosis and apoptotic bodies. Immunohistochemically, all cases were positive for cytoplasmic CD3ε and CD56. Epstein-Barr virus infection was demonstrated in all cases. Testicular NK/T-cell lymphoma, whether primary or secondary, was generally very aggressive with a poor outcome despite multimodality therapy. Novel molecular therapeutic targets and more effective treatments are needed, especially for disseminated or recurrent cases.