Intestinal metastasis from primary epidermoid anal carcinoma in a 34 year old male presented with acute bowel obstruction

Squamous cell carcinoma (SCC) of the anal canal is a rare condition comprising only 2-4% of all cancers of the colon, rectum and anus. The most common sites of metastases are liver and lung. We report a case of 34-year-old male, who presented with diarrhoeal illness and an acutely tender protruding anal lesion initially thought to be thrombosed external hemorrhoid. Examination under anaesthesia revealed a hard and fixed mass at the level of dentate line, which was biopsied. On histopathological examination, it was confirmed as primary moderately differentiated keratinising squamous cell carcinoma. Despite initial response to concomitant chemo-radiation, 4 months later, the patient presented with large bowel obstruction. On laparotomy, a large mass involving the terminal ileum and caecum was identified. Histopathological examination revealed metastatic spread from primary anal lesion. To the best of our knowledge, this is the first reported case of a squamous cell carcinoma of anus with bowel metastasis.