Retroperitoneal liposarcoma mimicking pheochromocytoma

Abstract

Retroperitoneal liposarcomas are rare mesenchymal tumors which carry a poor prognosis because of their late presentation. When symptoms do occur, they are usually nonspecific and related to mass effect or invasion of local structures. Rarely, retroperitoneal liposarcomas can clinically and biochemically mimic phaeochromocytomas. We discuss one such case of a 56-year-old Afro-Trinidadian female who presented to her primary care physician with a 3-month history of weakness, intermittent sweating, difficulty sleeping and elevated blood pressure. After a 2 week trial of an oral antihypertensive regime her blood pressure was still elevated and she complained of new right sided abdominal pain. A subsequent Computed Tomography scan of her abdomen revealed an enhancing, heterogeneous right suprarenal mass suspicious for pheochromocytoma. Urinary catecholamines were also elevated and an MRI of her abdomen supported the diagnosis of pheochromocytoma although intralesionsal fat was noted, an uncommon feature of pheochromocytomas. She was booked for laparoscopic adrenalectomy. Histological analysis of the resected specimen confirmed a dedifferentiated retroperitoneal liposarcoma. While the imaging features of phaeochromocytomas and retroperitoneal liposarcomas can be similar, the presence of intralesional fat on CT and MRI should favour the diagnosis of a retroperitoneal liposarcoma, albeit the clinical and biochemical picture.

Keywords

• Retroperitoneal liposarcoma
• Pheochromocytoma