Unusual presentation of rectal squamous cell carcinoma perforation-case report and literature review.

This is an unusual case of an obstructive rectal squamous cell carcinoma (SCC), causing perforation and a pelvic abscess, requiring source control and diverting colostomy. A 50-year-old female with chronic constipation presented with worsening right buttock pain for 1 month. On exam, the patient reported right hip tenderness. A computer tomography (CT) revealed rectal wall thickening with a presacral abscess. Due to the concern of rectal perforation with abscess she was taken to the operating room for proctoscopy with biopsy, colostomy diversion and drainage of the abscess over the right buttock. Pathology reported invasive rectal SCC. Rectal SCC presents similarly to rectal adenocarcinoma but its diagnosis must include special markers for cytokeratins. The treatment approach is controversial but adequately treated offers better survival than rectal ADC. Rectal SCC is rare and treated with chemoradiation however it must also be tailored to the variable acute presentations. Published by Oxford University Press and JSCR Publishing Ltd. 2021.