Sarcomatoid Carcinoma of the Ascending Colon: A Case Report and Literature Review.

BACKGROUND Sarcomatoid carcinoma is a rare tumor that can occur in different organs and anatomical locations. Colonic sarcomatoid carcinoma, also known as carcinosarcoma, is an extremely rare tumor, with only 32 cases reported world-wide. The pathogenesis and guidelines for treatment are poorly understood due to the rarity and invasiveness of the disease. CASE REPORT A 77-year-old woman presented with worsening lower abdominal pain and associated fever after having initially been diagnosed with stump appendicitis and associated phlegmon 3 weeks prior, which was treated with antibiotics. Repeat imaging revealed an extraluminal versus perforated colonic mass with associated phlegmon. The patient's condition continued to worsen, with development of obstructive-like symptoms, resulting in operative intervention involving a R2 right hemicolectomy, stapled ileo-colostomy, and partial omentectomy. The patient had an uneventful remainder of her hospitalization other than continued lower abdominal pain. After initial discharge, the patient presented to an outside hospital due to continued deterioration of health, with findings of an additional mass, likely secondary to the previous lymphadenopathy. Ultimately, goals of care were discussed, and the decision was made to provide palliative care, and the patient died due to her illness 32 days after the initial procedure. CONCLUSIONS Carcinosarcoma is an extremely rare tumor with scant research guiding treatment guidelines. Current guidelines gathered from previous case reports suggest treating colorectal carcinosarcoma as adenocarcinoma. Additional research and studies are needed to establish appropriate therapeutic guidelines for carcinosarcoma.