Leiomyosarcoma of the colon: A challenging diagnosis in young women - A case report

Abstract

Leiomyosarcoma (LMS) of the colon is an extremely rare colorectal malignancy, accounting for less than 0.1% of all colorectal cancers. The clinical symptoms of colonic LMS are often vague and nonspecific, including abdominal pain, changes in bowel habits, rectal bleeding, or an abdominal mass, which makes early diagnosis difficult. The majority of cases occur in middle-aged adults, with a slight male predominance. We report a rare case of colonic LMS in a young woman, whose clinical symptoms closely resembled those of a ruptured bleeding ovarian cyst or ectopic pregnancy, leading to an initial misdiagnosis. The definitive diagnosis was made through laparoscopic surgery and histopathological biopsy. Histopathological examination using histopathological examination (H&E) staining and immunohistochemistry (IHC) confirmed colonic LMS. Metastatic involvement was identified in 7 out of 11 regional lymph nodes. Our report highlights a very rare case of LMS involving the rectum and sigmoid colon, underscoring the diagnostic challenge in young female patients and emphasising the importance of surgical exploration and pathological confirmation in atypical pelvic presentations.