[Retroperitoneal tumors. Retroperitoneal myxoid liposarcoma. Report of a new case]. / Tumores retroperitoneales. Liposarcoma mixoide retroperitoneal. Presentación de un nuevo caso.

OBJECTIVE: To describe an additional case of a large retroperitoneal liposarcoma. METHODS/RESULTS: A case of a large retroperitoneal liposarcoma in a young male is presented. Treatment was by surgery. The clinical and pathological features, diagnosis, course and treatment of this lesion are discussed. CONCLUSIONS: Retroperitoneal tumors constitute a heterogeneous group of uncommon neoplasms of unknown etiology. Liposarcoma is the most frequent lesion in this group. It is usually asymptomatic and is often identified by the presence of a large abdominal mass. It is considered to be a peculiar lesion because of its biological and morphological features and course.