Deep Fibrous Histiocytoma of the Prostate Masquerading as Benign Prostatic Hyperplasia

Abstract

A bstract Fibrous histiocytoma is an uncommon clinical entity that arises in the subcutaneous or deep tissues. Rarely, it arises from the prostate. Although the malignant subtype has been reported by some authors, the benign subtype is scarce in the literature. We present the case of a 66-year-old male who had bladder outlet obstruction secondary to a huge pelvic mass. Initially, his symptoms were thought to be due to benign prostatic hyperplasia, however, an abdominopelvic computed tomography scan and pelvic magnetic resonance imaging showed a huge cystic pelvic mass that originated from the prostate. Eventually, he had open drainage of the mass and part of the sac was excised for examination. Histologically and immunohistochemically, this was confirmed to be a deep (benign) fibrous histiocytoma of the prostate.