Tubulovillous adenoma of anal canal: a case report

Tumors arising from the anal canal are usually of epithelial origin and are mostly squamous cell carcinoma or basal cell carcinoma. We present a case of benign anal adenomas arising from the anus, an extremely rare diagnosis. A 78-year-old white man presented with rectal bleeding of several months duration. Examination revealed a 4 cm friable mass attached to the anus by a stalk. At surgery, the mass was grasped with a Babcock forceps and was resected using electrocautery. Microscopic examination revealed a tubulovillus adenoma with no areas of high grade dysplasia or malignant transformation. The squamocolumnar junction was visible at the edges of the lesion confirming the anal origin of the tumor. We believe the tubulovillus adenoma arose from either an anal gland or its duct that opens into the anus. Although seen rarely, it is important to recognize and treat these tumors at an early stage because of their potential to transform into adenocarcinoma.