Primary Colonic Leiomyosarcoma Initially Diagnosed as Kaposi Sarcoma: A Case Report.

Primary colonic leiomyosarcomas are relatively uncommon mesenchymal tumors, often posing diagnostic challenges due to their overlapping features with other gastrointestinal tumors. In this article, we report the case of a 61-year-old male who presented with abdominal pain and weight loss, whose initial endoscopic biopsy was interpreted as colonic Kaposi sarcoma, with tumor-cell positivity for cluster of differentiation 34 and human herpesvirus 8. Further surgical intervention, characterized by a right radical hemicolectomy and histopathological analysis, revealed a primary colonic leiomyosarcoma. This case highlights the diagnostic complexity associated with colonic leiomyosarcomas, the importance of comprehensive histopathological assessment, and the need for timely surgical management. The clinical course of the patient analyzed illustrates how misclassification can alter therapeutic strategies, underscoring the value of a timely and accurate diagnosis in guiding appropriate oncological management.