Dedifferentiated retroperitoneal liposarcoma presenting as lower gastrointestinal bleeding, a case report and review of the literature.

Retroperitoneal sarcoma is a rare tumor that accounts for 10-15% of soft tissue malignancies. The incidence is 2.5 per million and liposarcoma accounts for approximately 20% of all retroperitoneal sarcomas. Treatment of retroperitoneal liposarcomas is primarily surgical and the ability to completely resect the turmor is the most important predictor of local recurrence and overall survival. Unfortunately, these tumors are almost always large at the time of diagnosis owing to their slow growth and vague symptoms. Abdominal discomfort is the presenting complaint in 60-70% and palpable mass on 70-80%, lower gastrointestinal bleeding is a rare presentation for these malignancies. These vague symptoms allows them to attain a size and extent which make treatment with tumorcidal doses of radiation difficult and likely to cause significant morbidity. We present a rare case of a dedifferentiated retroperitoneal liposarcoma presenting primarily as a lower gastrointestinal bleeding.