Successful treatment of primary malignant lymphoma of the penis by organ-preserving rituximab-containing chemotherapy.

Primary penile lymphoma is extremely rare. Here we report the case of a 67-year-old man with the chief complaints of difficulty in urination and priapism, who was eventually diagnosed with primary malignant lymphoma of the penis. Pathological examination of excision biopsy of the left inguinal lymph node revealed malignant CD20+ diffuse large B-cell lymphoma. We treated this patient with a systemic rituximab-chemotherapy regimen and obtained good results, in terms of both functional and cosmetic outcomes. Soluble interleukin-2 receptor was a useful tumor marker for evaluating the therapeutic effect. The patient has been in remission for 10 months after the discontinuation of chemotherapy.