Primary Multiple Mesenteric Liposarcoma of the Transverse Mesocolon
A 63-year-old female with no comorbidities presented with gradually progressive, painless, upper abdominal distension and loss of appetite for one year. Physical examination revealed a distended abdomen and epigastrium, as well as right and left hypochondrium fullness extending to the umbilicus. A nontender mass of about 15 cm × 12 cm in size was palpable in the epigastrium, the right and the left hypochondrium, and the umbilical regions. The mass was firm, had a smooth surface, moved from side to side, and fell forward when the patient was in the knee-elbow position. The findings of abdominopelvic ultrasound showed a 12.5 cm × 9.6 cm uniformly echogenic lesion with unclear margins in the midline; the lesion occupied the epigastric and umbilical regions and pushed bowel loops to the periphery.\nContrast enhanced computed tomography (CECT) of the abdomen and the pelvis showed a space-occupying lesion in the epigastric/umbilical region measuring 16 cm × 16 cm × 10 cm. The lesion was a nonhomogenous mass with irregular enhancement and displaced the bowel loops (straddling sign, ). Bowel loops were located between the tumor and the anterior abdominal wall, suggesting a probable mesenteric origin []. No evidence of a retroperitoneal lymphadenopathy was found, and the lesion was reported as a large teratoma occupying the anterior epigastric/umbilical regions with a possible mesenteric origin.\nThe patient underwent surgery. A midline laparotomy was done, and the peritoneal cavity was explored. A huge lipomatous mass measuring 23 cm × 16 cm × 12 cm was found in the lesser sac over the transverse mesocolon. The lesser sac was opened, and the mass was found to be well defined without any major vascular invasion. The tumor was excised in toto with macroscopically negative margins. On further exploration, multiple such separated masses with sizes ranging from 4 to 7 cm were found to be attached to the transverse mesocolon ( and ), and each was excised with clear margins. Postoperative period was uneventful. Histopathology showed similar features suggestive of an atypical lipoma or a well-differentiated liposarcoma in all of the excised lesions, suggesting possible multicentricity or the presence of satellite nodules.