Primary gastrointestinal liposarcoma-a clinicopathological study of 8 cases of a rare entity.

Primary gastrointestinal liposarcoma is rare, and information regarding this entity is largely based on single case studies. We report on 8 patients with primary liposarcoma of the gastrointestinal tract and review the pertinent literature. The cohort includes 6 men and 2 women who ranged in age from 51 to 81 years (median 68.5). Two tumors arose in the stomach, 4 in the small intestine, and 2 in the large intestine. Tumors ranged in size from 2.5 to 14.5 cm (median 7 cm), originated in the submucosa or muscularis propria of the intestinal wall, and frequently protruded into the bowel lumen, resulting in mucosal ulceration and luminal obstruction. Six tumors were dedifferentiated liposarcomas, and 2 were well-differentiated liposarcoma. Surgical excision was performed on all tumors except for 1 case of dedifferentiated liposarcoma. On follow-up, 1 patient with dedifferentiated liposarcoma developed a lytic sacral lesion suspicious for metastasis 4 months after resection of the primary, and another underwent marginal resection and presented with recurrence 4 years later, had tumor re-resection, and was considered disease-free at 6 weeks postsurgery. A third patient with dedifferentiated liposarcoma was alive with unknown disease status at 17 months following surgery, and another patient with dedifferentiated liposarcoma was alive without evidence of disease at 30 months following surgery. No follow-up information on the remaining patients is available. Overall, liposarcomas of the intestinal tract are most frequently high-grade dedifferentiated tumors that are biologically aggressive and require surgical excision with widely negative margins to help reduce the risk of local recurrence and dissemination. Important in the differential diagnosis is malignant gastrointestinal stromal tumor. Care must be taken not to misdiagnose one entity for the other because the correct diagnosis carries important therapeutic implications.