Perineal Ectopic Prostate Tissue: A Rare Case and Its Clinical Implications

Ectopic prostate tissue is a rare condition characterized by the presence of prostate glands outside their typicalanatomical location, rather than the entire organ being displaced. While it is most commonly observed in thelower male genitourinary system, it has also been reported in various other sites, including the pericolic fat, thefemale genitourinary system, and even the spleen. The most common location is the urinary bladder trigone,though it can also appear in the periurethral area or at the bladder neck. Here, we present a case involvingperineal ectopic prostate tissue that manifested as a significant mass. A 52-year-old man visited a colorectalclinic due to a bulging, mass-like lesion in the perineal region. Perineal soft tissue sonography identified asolid-cystic mass, while pelvic magnetic resonance imaging (MRI) revealed a large solid-cystic mass locatedposterior to the sacrum, beneath the skin. Physical examination demonstrated a palpable, large perineal massextending from the inferior border of the scrotum to the anterolateral aspect of the anus. Laboratory data werewithin normal limits. Both tru-cut biopsy and fine-needle aspiration (FNA) indicated a bloody, low-cellularityspecimen with no malignant cells. Subsequently, the entire mass was excised via a transperineal approach.Pathological and immunohistochemical studies confirmed the presence of ectopic prostate tissue without anysigns of malignancy. Consequently, ectopic prostate tissue should be considered in the differential diagnosis ofany perineal mass, and surgical excision is recommended due to the potential risk of malignancy.