Liposarcoma of the oral cavity. Clinical, tissue culture, and ultrastructure study of a case.

This report represents the histologic, tissue culture, and ultrastructural findings in a well-differentiated liposarcoma that originated in the buccal mucosa of a 42-year-old female. A variety of cell types were identified in the recurrent tumor with light and electron microscopy; namely, rounded mesenchymal cells, signet-ring cells, multivacuolated cells and bizarre giant cells. The giant cells possessed large, multilobed nuclei with large nucleoli. Mitochondria appeared in varied numbers and Golgi zones were highly organized. Cytoplasmic inclusions were variable in the cytoplasm of the tumor cells. A morphologic variation among cells was also noted in the tissue culture media. The histogenesis of this unusual and sometimes difficult to interpret neoplasm of the oral cavity is discussed.