A novel submucosa nodule of the rectum: A case of the ectopic prostatic tissue outside the urinary tract

Abstract

Ectopic prostatic tissue is an underreported entity, which is found most commonly in the lower male genitourinary tract, and ectopic prostate tissue outside the urinary tract is even rarer. Our patient was a unique case of ectopic prostatic tissue within submucosa of the rectum. The patient presented with rectal bleeding, and a firm, round solid submucosa nodule found in the anterior rectum at digital rectal examination, it was 1cm in diameter and 5cm above the anal verge. The size and submucosa location of this nodule were confirmed by the colonoscopy and MRI. After being removed surgically, the histopathology of the specimen sections possessed typical prostatic acini and stroma, meanwhile the immunohistochemical staining for prostate specific antigen confirmed its’ prostatic nature. It is the first case to date, which involves the mural of rectum. We hypothesizes that the etiologies of ectopic prostatic tissue within the submucosa rectum attribute to embryogenetic abnormality.

Ectopic Prostatic Tissue in the Rectum: A Case Report

“…Its histological and immunohistochemical characteristics are not distinguishable from the normal prostate tissue (1). To date, less than five cases of rectal, anal, or perirectal EPT have been reported (2)(3)(4). However, to the best of our knowledge, there is no single published report describing the radiographic findings of perirectal EPT.…”

Prostate cancer arising in ectopic prostatic tissue within the left seminal vesicle: a rare case diagnosed with multi-parametric magnetic resonance imaging and magnetic resonance imaging-transrectal ultrasound fusion biopsy

“…While the phenomenon of ectopic prostatic glandular tissue in the genitourinary tract is rare, it is not entirely uncommon. While the majority of cases of benign prostatic ectopia have been reported in the urinary bladder [ 1 , 2 ] and urethra [ 3 ], cases have also been described in the retro-vesicular space [ 4 , 5 ], seminal vesicles [ 6 – 8 ], epididymis [ 9 ], testis [ 10 ], and rectum [ 11 ]. Cancer arising in prostatic ectopia has only been reported four times in the literature, all in the urinary bladder and urethra [ 12 – 15 ].…”

Imaging of Non-malignant Conditions of the Prostate and Seminal Vesicles: A Comprehensive Review

“…51 Prostate hyperplasia and neoplasms developing in EPT have been reported. 51,52 MRI shows the typical signal intensity of the prostate gland with or without hyperplasia and ►Fig. 17 is an example of EPT in the right distal ureter.…”

“…It is mostly reported in the urethra and bladder and less commonly reported in the genital tract involving SV, epididymis, and testis. 50 51 There are case reports of EPT described in other locations, including the bowel, 52 pelvis, 53 54 and spleen. 55 The origin of this around the lower urinary tract is believed to be vestigial remnants of developmental migration, while other sites may involve metaplasia or misplacement of prostate glands during development.…”