Diffuse large B-cell lymphoma of the prostate.

In this article, we review prostatic lymphomas and discuss the differential diagnosis of high-grade malignant neoplasms of the prostate. We illustrate this with a case of a 46-year-old man seen with lower urinary tract obstruction who had diffuse involvement by a high-grade malignancy on prostate biopsy. Morphologic evaluation and immunohistochemistry were consistent with diffuse large B-cell lymphoma of the prostate. Workup with positron emission tomography-computed tomography demonstrated intensely hypermetabolic lymph nodes in the mediastinum, as well as widespread osseous involvement and involvement of the pancreatic tail, prostate, and urinary bladder, suggesting secondary prostatic involvement by a nodal lymphoma. Lymphomas of the prostate are uncommon in surgical pathology practice and usually represent secondary involvement from leukemia/lymphoma at a more typical site. Chronic lymphocytic leukemia/small lymphocytic lymphoma is the most common subtype.