A Case of Rectal Carcinoma in a Part of a Giant Periproctal Abscess

Abstract: A 58-year-old male was admitted to our hospital complaining of perineal pain and weight loss. On digital examination, a hard mass with a central depression was palpable in the circumference of the rectum. A barium enema study revealed a giant periproctal abscess formation, and a colonoscopy showed a giant irregular-shaped ulceration in the circumference of the rectum. Biopsy specimens obtained from the rectal ulcer revealed a well differentiated adenocarcinoma, and this case was diagnosed as being carcinoma of the rectum with periproctal abscess formation. A pelvic exenteration and colostomy were performed. The macroscopic findings of the resected rectal specimen showed a giant abscess formation measuring 13 cm over the anal verge in the circumference of the lower rectum. The abscess, with a thickened wall measuring 50 mm, was accompanied by an ulcerated lesion on its oral and anal side. The tumor was adherent to the bladder and prostate with direct invasion. The post operative diagnosis made was an unclassified type of rectal carcinoma (type 5). Its clinical staging was stage 5 (HIPON1A3) in gross appearance. The histopathological findings of the resected specimen indicated a poorly differentiated adenocarcinoma partly containing signet ring cell carcinoma. The frequency with which a rectal carcinoma with a regional abscess has been reported is less than 1%. It has been assumed that a regional abscess is caused by the perforation of the rectum contributing with the invasion of carcinoma over the proper muscle layer. In this case, it was inferred that the rapid development of this tumor caused secondary, ischemia at its center and then an abscess was formed with tumor necrosis.