Clinical outcome of incidental pelvic node malignant B-cell lymphomas discovered at the time of radical prostatectomy

Incidental pelvic node malignant B-cell lymphomas diagnosed at the time of radical prostatectomy are rare. Their clinical outcome has not been studied. We studied thirteen such cases with long-term clinical follow-up. Patients were followed between 9 and 94 months after surgery. Of 13 cases, 9 were chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), 3 marginal zone B-cell lymphoma (MZL) and 1 mantle cell lymphoma (MCL). All 13 patients did not receive radiation or chemotherapy; and five of 13 cases showed hematologic evidence of lymphoma progression between 1 and 5 months after radical prostatectomy. After progression, the mantle cell lymphoma patient received aggressive chemotherapy and had systemic dissemination. Two of 13 cases had recurrent prostate carcinoma. None of 13 patients had died from lymphoma or prostate carcinoma at the last follow-up. In conclusion, most incidental pelvic node lymphomas (8/13) showed no evidence of systemic dissemination to peripheral blood or bone marrow after a mean 42.8 weeks of follow-up despite the fact that no additional treatment was given. Strong consideration should be given to withholding further treatment in patients diagnosed with pelvic low-grade B-cell lymphoma at the time of radical prostatectomy until disease progression occurs.