Dendritic Myxofibrolipoma

ABSTRACT

Dendritic myxofibrolipoma is a recently described disease entity that represents a distinctive benign soft tissue neoplasm showing the combined features of spindle cell lipoma and the solitary fibrous tumor. Immunohistochemical stains reveal a strong positivity for vimentin, CD34 and bcl-2, which highlight the dendritic nature of the tumor cells by demonstrating slender complex cytoplasmic prolongations. There have been 12 cases of dendritic myxofibrolipomas reported in literature. In Korea, none of the cases have been described. We report such a case with a 28-year-old man who had a palpable subcutaneous mass on his right shoulder for 4 months. Grossly, the removed mass measured 11X7X5 cm and appeared to be a well-encapsulated, lipomatous tumor with marked myxoid appearance. Microscopically, this tumor consisted of spindle cells admixed with dense collagen fibers and mature adipocytes in abundant myxoid stroma with high vascularity. Immunohistochemically, the tumor cells were strongly reactive for vimentin and CD34 and weakly reactive for bcl-2, and negative for S-100 protein.