BACKGROUND: Squamous cell carcinoma (SCC) of the sigmoid colon is an exceedingly rare subtype of colorectal cancer (CRC) associated with chronic inflammatory conditions. Due to its variable clinical presentation ranging from subclinical to fully symptomatic and limited available information, it poses a diagnostic challenge. We aim to provide a review of the current literature and raise awareness about the importance of a thorough clinical analysis for an early diagnosis. CASE PRESENTATION: We describe the case of a 59-year-old Peruvian woman with a medical history of diverticular disease and irritable bowel syndrome. The patient presented with nonspecific symptoms such as abdominal discomfort, constipation, and bloating. Diagnostic tests and biopsy revealed a rare case of squamous cell carcinoma of the sigmoid colon. The patient underwent surgical resection and adjuvant chemotherapy. CONCLUSION: Despite the rarity of this type of cancer in the colon, the patient's clinical course highlights the importance of considering it as a potential diagnosis in patients with nonspecific symptoms and a history of gastrointestinal disorders. Surgical treatment followed by radiotherapy is the preferred management. Factors such as lack of postoperative complications and the stage of the neoplasia can augur a positive. PROGNOSIS: A prompt diagnosis is crucial, as detecting a neoplasia in its early stages can make surgery more effective.