A Rare Case of Primary Renal Liposarcoma

Within the broad category of retroperitoneal tumors, primary renal liposarcoma represents an exceedingly rare entity, accounting for less than 1% of tumors.Presentations are often nonspecific, but providers should focus on initial stabilization and consultation with specialists.We present a rare case of primary renal liposarcoma presenting with nonspecific symptoms.A 79-year-old female presented with an abdominal mass, nausea, and bilateral lower extremity edema.Computed tomography (CT) revealed a heterogeneous right retroperitoneal mass measuring 20.6 x 14.9 x 16.0 cm.A subsequent biopsy showed de-differentiated liposarcoma positive for MDM2 (via amplification testing) and CD34 (atypical for this entity).The patient was ultimately discharged and had extensive outpatient resection done.The diagnostic pathway for primary renal liposarcoma begins with a CT, followed by tissue biopsy.Unfortunately, renal liposarcomas carry a poor prognosis because these tumors grow remarkably large due to the ability of the retroperitoneum to accommodate them, and the location itself causes anatomical constraints to surgery.This case highlights that even in the absence of severe clinical complaints, malignant pathology cannot be ruled out.The emergency department (ED) has become an increasingly important pathway for cancer diagnosis, and emergency medicine (EM) physicians play an essential role in initiating multidisciplinary care of patients with aggressive malignancies.