Two cases of primary leiomyosarcoma of sigmoid colon treated with laparoscopic surgery: A case report and a review of literature

Introduction and importance: Leiomyosarcoma (LMS) of the colon is an extremely rare and highly invasive tumor arising from the muscularis propria of the gastrointestinal tract. After the introduction of oncogenic role of KIT by immunohistochemistry (IHC), the reported cases of gastrointestinal leiomyosarcoma were highly limited. True LMS of the colon is such a rare disorder that there isn't much description of its nature. Case presentation: We reported two very rare cases of primary leiomyosarcoma of sigmoid colon, which referred to our institution with symptoms of abdominal pain, lower GI bleeding and fatigue. After the initial investigations, both patients were diagnosed with primary LMS of sigmoid colon that underwent laparoscopic tumor resection. Clinical discussion: The classical colonic LMS presents with a vast majority of non-specific symptoms including mild abdominal pain, fresh/obscure rectal bleeding, and weight loss. The most common location for colonic LMS is the sigmoid colon, and ascending colon. The prognostic factors for the disease outcome have not been established properly; however, patient age, tumor size/grade, and local/distant dissemination are of great importance. Conclusion: Herein, we reported two rare cases of primary leiomyosarcoma of sigmoid colon that was treated with laparoscopic surgery.