HMGA2-Rearranged Lipoblastoma in an Adult Patient With Novel GRIP1 Gene Fusion Partner.

Lipoblastoma is a benign tumor of adipocytic differentiation originating from embryonal white fat that is commonly described in young children, with rare cases arising in adults. PLAG1 gene (8q11-13) rearrangement is a characteristic feature of lipoblastoma. However, HMGA2 gene rearrangement has also been reported in a few cases of lipoblastoma, with the gene fusion partners reported thus far being EP400, FGD6, and GSN genes. Herein, we report an HMGA2-rearranged lipoblastoma arising in the chin of a 51-year-old female with a novel gene fusion partner, the GRIP1 gene, that has not been previously described in lipoblastomas. Our case adds to the growing pool of gene fusion partners of HMGA2-rearranged lipoblastomas and expands the molecular spectrum of lipoblastomas in general beyond the previously described PLAG1 gene rearrangements, thereby suggesting that lipoblastomas may be more molecularly heterogeneous than previously appreciated.