2022 Volume 21 Issue 2 Pages 98-102
A 63-year-old man complained of a tumor on the left back that had been slowly enlarging for 10 years. The tumor was subcutaneous beneath an elastic and hard lesion. Tumor with a welldefined margin was removed under local anesthesia. The histological findings included atypical spindle cells, adipocytes, lipoblast, and pleomorphic cells in variable amounts of collagenous and myxoid extracellular matrix. Immunohistochemically, the tumor cells expressed CDK4. None of the tumor cells showed expression of MDM2 and RB1. We diagnosed this tumor as an atypical spindle cell/pleomorphic lipomatous tumor. This tumor is rare and represents a new concept as a benign adipocytic tumor. Further studies are needed to clarify this tumor concept. Skin Research, 21 : 98-102, 2022
