Chondroid lipoma. A newly described lesion that may be mistaken for malignancy.

A case of chondroid lipoma located in the submandibular region of a 21-year-old man is presented. On macroscopic evaluation the tumor was lobulated and quite yellow. Microscopic examination showed that this tumor was composed of mature adipose tissue and eosinophilic cells. The eosinophilic cells displayed single or multiple vacuoles and resembled lipoblast or hibernoma-like cells. These were set in a myxoid or chondromyxoid stroma. Most cells reacted with antibodies directed against vimentin and neuron-specific enolase. Focal weak positivity for S-100 protein was noted. Principal considerations in the histopathologic differential diagnosis included hibernoma, myxoid liposarcoma, and extraskeletal myxoid chondrosarcoma (chordoid sarcoma).