A rare case of a giant retroperitoneal lipoma with multiple limb and trunk lipomata without familial multiple lipomatosis

Abstract

Retroperitoneal lipoma is exceedingly rare, and due to the difficulty in distinguishing between retroperitoneal lipoma and well-differentiated liposarcoma (WDLS), recommendation is en-bloc resection. A 58-year-old male was investigated for scrotal swelling, ultrasound and computed tomography showed a well-defined lipomatous mass occupying much of the left side of the lower abdomen. At laparotomy, a large left-sided retroperitoneal mass was found. Histology reported a 160 mm × 150 mm × 90 mm fatty tumour weighing 1540 g. MDM2 gene amplification was not present on fluorescence in situ hybridization. No significant somatic signatures were identified on whole exome sequencing. Retroperitoneal fatty tumours represent a diagnostic dilemma. Sampling via core biopsy has been recorded at 85% accuracy for WDLS. Positive amplification of the MDM2 gene supports a diagnosis of WDLS; however, a negative biopsy does not exclude the diagnosis due to varied amplification among different cells in the same tumour.

Giant retroperitoneal well differentiated liposarcoma: A case report and literature review

“…Like in the case of our patient, who had been asymptomatic throughout the illness except from a minor, nebulous abdominal ache. The clinical symptoms are often ambiguous [ 30 ]. Imaging tests are therefore essential in the diagnosis of malignant tumors.…”

Intra-Abdominal and Retroperitoneal Benign Lipomatous Tumors—An Extremely Rare Mimic of Liposarcoma and its Diagnostic Challenge

“…Ruling out other possibilities becomes necessary when lipomas present in unusual sites or if they are remarkably large. Lipomas have been recognized to occur in the retroperitoneum but prior to, and since, Macarenco et al's large series, 2 it is only described in case reports of unusual presentations, 10 - 19 such that additional experience in clinical–pathological findings and differential diagnostic considerations are difficult to find. In this study, we describe the clinicopathologic features of 9 additional abdominal cavity lipomas that were histologically and molecularly distinguished from WD-LPS.…”