Cellular Angiofibroma Presenting as a Subepithelial Rectal Mass

Abstract

A very rare case of cellular angiofibroma arising from the rectum in a 62-year-old man with a normal colonoscopy 2 years earlier is reported. To our knowledge, this is the first such case reported in the literature. The tumor was transanally excised with clear margins, and the patient had no postoperative complications. It is key to accurately differentiate this lesion from other subepithelial rectal tumors and more aggressive genital soft tissue tumors because clinical management varies. We performed a review of clinical records and pathology as well as an extensive literature review.

Figure 1.

MRI of the pelvis-prostate with incidental low rectal mass. (A) MRI T2 rectal mass without gadolinium contrast-low rectal submucosal exophytic lesion abutting the external sphincter fibers and posterior aspect of the prostate. (B) MRI DWI—There is loss of outer muscularis layer and diffusion restriction, findings which make it suspicious for neoplasm. DWI, diffusion weighted imaging; MRI, magnetic resonance imaging.

Figure 2.

Histopathology of rectal cellular angiofibroma. (A) The tumor is composed of uniform, bland, spindle cells accompanied by thick-walled vessels (hematoxylin and eosin, original magnification 400×); (B) The tumor cells are positive for CD34 (3,3′-Diaminobenzidine as chromogen, original magnification 400×); (C) The tumor cells are positive for ER (3,3′-diaminobenzidine as chromogen, original magnification 400×); (D) The tumor cells are positive for AR (3,3′-diaminobenzidine as chromogen, original magnification 400×). AR, androgen receptor; ER, estrogen receptor.