Retroperitoneal Hibernoma: Exhibition of Three Case Reports and Literature Review

Abstract

Hibernoma is a rare benign tumor that becomes from the vestiges of fetal brown adipose tissue. It can be located on different regions of the body, being tight the most frequent. Retroperitoneal region is approximately of 9.4%. The first person to describe this histological type was Merkel. To the present, there are only described 25 cases on this location. It has a slowly growth, so it is normally asymptomatic, and it usually presents doing compression of different structures. To diagnose the MRI is the best prove, although biopsy will provide definite diagnosis describing four possible variants. Immunochemistry of MDM2, CDK4 and p16 genes is really important to do the differential diagnosis with well-differentiated liposarcoma (WDLS). Only one extensive review of hibernoma with 170 cases on different regions is published. But there is no review on literature specifically of retroperitoneal region, so this is the purpose of the current study. Following we present three more cases of retroperitoneal hibernoma that we have treat on our Mesenchymal Tumours Unit and a revision of the previously published.