Yi Yan1, Yong Jia2, Mohammad Akra4, Shady Attalla5, Miao Lu2 and Signy Holmes1,3*
1Department of Radiology, University of Manitoba, Canada
2Department of Pathology, University of Manitoba, Canada
3Department of Radiology & Diagnostic Imaging, Cancer Care Manitoba, Canada
4Cancer Care Manitoba, Canada
5Ain Shams University, Egypt
Liposarcoma is one of the most common primary retroperitoneal neoplasms, and the perinephric space is a classic location. Liposarcoma displays a wide range of radiographic features depending on histological types and tumor size, and dedifferentiated liposarcoma can present with an even broader spectrum of imaging findings; therefore, the diagnosis of liposarcoma often requires tissue sampling. We present a unique case of a giant perinephric dedifferentiated liposarcoma mimicking a cystic renal tumor.
A 48-year-old man presented to the emergency department with worsening of 2 months of sciatica. Lumbar spine CT revealed disc herniation at L4-L5 level with an incidental finding of a large mass occupying the left retroperitoneum. Subsequent abdominal CT demonstrated a well-defined 20 cm cystic mass intimate to the lower pole of the left kidney that contained no solid components or foci of macroscopic fat. The favored diagnosis was cystic renal cell carcinoma. MRI was advised for further characterization, but unfortunately was terminated early due to the patient's claustrophobia. The patient was subsequently referred for urology consultation. Since the image findings suggested cystic renal malignancy, a right radical nephrectomy was performed. Grossly, the tumor showed a predominantly gelatinous and glistening cut surface with small pale yellow fleshy component. Occasional hemorrhagic areas were also present. The final diagnosis was dedifferentiated liposarcoma arising from the perinephric tissue.
Our case highlights that, when confronted with a large perinephric cystic mass on CT scan, both benign and malignant etiologies (i.e. extra-renal AML, cystic RCC and dedifferentiated perinephric liposarcoma) should be included in the differential diagnosis.
Perinephric liposarcoma; Dedifferentiated liposarcoma cystic renal mass
Yan Y, Jia Y, Akra M, Attalla S, Lu M, Holmes S. Giant Perinephric Dedifferentiated Liposarcoma Masquerading Cystic Renal Tumor: A Case Report and Literature Review. Clin Oncol. 2021;6:1798..