Well differentiated "lipoma-like" liposarcoma of the sigmoid mesocolon and multiple lipomatosis of the rectosigmoid colon. Report of a case.

Liposarcoma is the second most common soft tissue sarcoma in adults. These neoplasms take their origin from primitive mesenchymal cells and are rarely encountered in fat rich areas, such as subcutaneous tissue and/or the subserosa of the intestinal tract which, on the contrary, are the two most common sites of lipomas. The two major locations of liposarcomas are the extremities and the retroperitoneum followed with much less frequency by the inguinal region. Other sites are uncommon, particularly the mesentery (9 cases to date in the literature) and, even more so, the mesocolon (only 3 cases of primary sarcoma of the mesocolon reported to date). This paper reports on the case of a well differentiated "lipoma-like" liposarcoma of the sigmoid mesocolon, associated with multiple lipomatosis of the recto-sigmoid colon in a 75 year-old female patient. Surgical treatment consisted of a trans-anal extra-peritoneal anterior resection by CEEA 28 stapler under endoscopic vision. The patient has been followed up for the last 2 years and is still disease-free and well. The peculiarity of the case consists in the contemporaneous presence in close contiguity of two different rare neoplasms whose association is not yet known.