We experienced a rare case of primary leiomyosarcoma of sigmoid mesentery. A 45-year-old woman was presented to us with left iliac fossa mass and discomfort for 4-month duration. CT scan of abdomen and pelvis revealed a huge mass 14 cm×14 cm×16 cm occupying left iliac fossa mimicked having a large left ovarian carcinoma. She was subsequently planned for elective total abdominal hysterectomy and bilateral salpingo-oophorectomy by gynaecology team. During laparotomy, a huge mass was revealed arising from sigmoid mesentery invaded to the left lower ureter. Curative resection was done and pathological findings show the tumour being leiomyosarcoma with immunohistochemistry tests on caldesmon, desmin, smooth muscle actin and CD34 reagent all positive. Clinicopathological and literature review of this rare primary leiomyosarcoma of mesocolon was discussed in our case presentation.

The NBI system in colonoscopy was capable of distinguishing neoplastic from non-neoplastic colorectal lesions. It indicates an acceptable level of agreement with histopathology, the gold standard. However, the role of NBI in screening and surveillance in Malaysia still needs further evaluation and exploration.

A 61-year-old gentleman presented with small bowel intussusception from small bowel melanoma intussusceptum. He complains of intermittent abdominal distension but no history of intestinal obstruction. Apart from this, he was also symptomatic anemia which required repeated transfusion for the past few months. The contrast-enhanced computed tomography of the abdomen shows an omental mass with small bowel intussusception. He then underwent an exploratory laparotomy with segmental resection of the affected segment. Histopathological examination confirmed primary gastrointestinal melanoma. Multiple small bowel malignant melanoma is a rare disease. It remains a controversial diagnosis as it may be a primary or metastasis from an unidentified or regressed primary cutaneous melanoma. Prompt surgical intervention enables us to obtain tissue diagnosis, prevent complete intestinal obstruction and strategize the goals of treatment for the patient.