Rare Low-Grade Undifferentiated Sarcoma of the Colon: A Case Report

Abstract Primary colorectal sarcomas are exceedingly rare and account for approximately 0.1% of all colorectal cancers. Among these, undifferentiated colonic sarcomas are even less common, and presentation with vague, nonspecific symptoms can make the diagnosis challenging. In this report, we present a 42-year-old man who experienced persistent fatigue, night sweats, weight loss, and anemia. He was found to have a large hepatic flexure mass adherent to the gallbladder. He underwent an extended right hemicolectomy with en bloc cholecystectomy and portal lymph node dissection. The pathology results showed a low-grade undifferentiated colonic sarcoma with negative margins and no lymph node involvement. To our knowledge, there are few reported cases of undifferentiated sarcoma of the colon. Our case highlights the diagnostic challenge of vague systemic symptoms, underscores the importance of a broad differential for large colonic masses, and contributes to the limited literature on this rare cancer type. Currently, there are fewer than 10 similar cases reported in the literature.