Spindle Cell Lipoma : Microscopic
Microscopic Features: Spindle cell/pleomorphic lipomas have a range of morphologic appearances. A typical case consists of an admixture of mature adipocytes and bland spindle cells in about equal proportions set in a myxoid and fibrous stroma. Some tumors are lipoma-like with abundant mature adipose tissue and only scattered foci of spindle cells or pleomorphic cells (see left panel). Others are composed predominantly or exclusively of spindle/pleomorphic cells. These fat-free lipomas may show pure spindle cell pattern (see right panel), pure pleomorphic pattern, or an admixture of the two.