SMARCA4-Deficient Undifferentiated Tumor of the Right Colon in a Patient With Ulcerative Colitis.

Undifferentiated gastrointestinal tumors with SMARCA4 deficiency are a rare subset of malignancies that often present as advanced, rapidly progressive disease. SMARCA4 loss is identified by immunohistochemistry, and affected tumors demonstrate distinct morphological features. Ulcerative colitis is a chronic inflammatory disorder that predisposes patients to colitis-associated colorectal cancer through a variety of genetic alterations. We present the case of a 31-year-old patient with a SMARCA4-deficient undifferentiated right-sided colon cancer detected during surveillance colonoscopy for ulcerative colitis. We also review the potential association between ulcerative colitis and SMARCA4-deficient undifferentiated gastrointestinal tumors.