Liposarcoma of the colon.

Lipomas are frequently encountered in the gastrointestinal tract but liposarcomas in this location are extremely rare. We present the first reported case of primary colonic liposarcoma. CASE REPORT: A 54 year old female presented with lethargy, abdominal discomfort, diarrhoea, and loss of 7 kg weight. She was clinically anaemic. A firm, irregular 6 cm mass was palpable in the right upper quadrant of the abdomen, and a 6.5 cm mass in the left breast. Haemoglobin was 7.3 g/dl with microcytic hypochromic indices. Faecal occult blood tests were positive. Barium enema revealed a polypoid tumour in the colon just proximal to the hepatic flexure (Fig 1). Fine needle aspiration cytology confirmed the presence of a carcinoma in the left breast. Right hemi-colectomy and left mastectomy operations were performed. There was no clinical, operative or radiological evidence of primary tumour at any other site. Pathological examination revealed a 6 x 4 x 5 cm polypoid tumour projecting into the colonic lumen (Fig 2). It was largely covered by mucosa with only focal areas of surface ulceration. The cut surface showed multi-lobulated well circumscribed greyish yellow polypoid tumour of firm consistency with no gross evidence of haemorrhage or necrosis. Histological section showed the classical features of the pleomorphic variant of liposarcoma, including univacuolar and multivacuolar lipoblasts with bizarre forms, multinucleated giant cells and numerous mitotic figures (Fig 3). Immunohistochemical markers for epithelial, smooth muscle and neural antigens were all negative. Oil red fat stain was strongly positive. Electronmicroscopy confirmed the lipoblastic and lipocystic differentiation of the tumour cells. One enlarged mesocolic lymph node showed metastatic involvement with tumour cells similar to that of the primary colonic neoplasm