[A case report of spindle cell lipoma with a marked myxoid change].

Spindle cell lipoma is a specific variant of lipoma that displays several characteristic clinicopathologic features proposed by Enzinger and Harvey. A tumor located in the nucheal subcutis of a 45-year-old man showed a mixture of fat cells and spindle cells with marked myxoid change of the matrix. Its fine structure revealed prominent microfilaments in the spindle cells. Immunohistochemical study suggested that these filaments were probably vimentin. Accumulated filaments and myxoid matrix containing hyaluronic acid may be degenerative rather than synthetic. The cell origin of the tumor may be a mixture of two cell types differentiating toward fat cells and fibroblastic cells.