Squamous cell carcinoma of the sigmoid colon: a rare case report.

Squamous cell carcinoma (SCC) of the colorectum is rare malignancy. It constitutes only 0.1-0.25 per 1000 cases of colorectal carcinoma. Here, we report a rare case of primary SCC of the sigmoid colon in a 40-year-old female from Western Uttar Pradesh, India. She presented with acute intestinal obstruction and a history of altered bowel habits and decreased appetite. Surgical resection revealed a constricted tumor in the sigmoid colon. Histopathological analysis confirmed the diagnosis of SCC with no lymph node involvement (0/32). The patient received four cycles of adjuvant chemotherapy (FOLFOX regimen) and has remained disease-free during a 3-year follow-up. Given its rarity, there is no established treatment protocol for colorectal SCC. Surgical resection remains the mainstay of treatment, with uncertain benefits from chemotherapy or radiotherapy. Early diagnosis and long-term follow-up are crucial for favorable outcomes in such uncommon presentations.