Lymphangiomas are rare benign congenital malformations of the lymphatic system. Clinical presentation varies from asymptomatic masses to acute abdominal pain. A 25-year-old female who presented with acute onset of abdominal distension and severe pelvic pain is presented. As a palpable mass was found on the pelvic examination and ultrasonography demonstrated a hypoechoic cystic mass, an ovarian malignancy was suspected. Exploratory laparotomy was performed and revealed cystic lymphangioma of the sigmoid colon. The clinical, radiological and pathological findings of the patient are discussed with a brief review of the literature.