Retroperitoneal dedifferentiated liposarcoma lacking MDM2 amplification in a patient with a germ line CHEK2 mutation.

[dedifferentiated liposarcoma]

Germ line mutations in genes that encode proteins involved in the DNA damage response predispose patients to a variety of tumors . Checkpoint kinase 2 , encoded by the CHEK 2 gene , is important in transducing the DNA damage response . Germ line CHEK 2 mutations are seen in a subset of patients with a familial breast cancer and sarcoma phenotype . We report a case of retroperitoneal dedifferentiated liposarcoma in a 61 -year -old female with germ line CHEK 2 mutation . MDM 2 gene amplification normally present and used to aid in the diagnosis of retroperitoneal dedifferentiated liposarcoma was absent in this case . Lack of MDM 2 overexpression has similarly been reported in liposarcomas arising in patients with germ line TP 53 mutations . We propose this case may highlight a nonamplified MDM 2 phenotype in well- and dedifferentiated liposarcomas arising in patients with germ line mutations of genes involved in p 53 -associated DNA damage response pathways .