[Case report of lipoleiomyoma of the uterus].

A 64-year-old woman with a lipoleiomyoma of the uterus is reported. Histologically, the tumor was predominantly composed of mature fatty tissue and intermingled with irregular-shaped fibromuscular tissue. The fibromuscular tissue showed mast cell infiltration. Ultrastructural study revealed the smooth muscle component to have irregularly indented nuclei, there were cytoplasmic fusiform dense patches, discontinuous external lamina, and occasional fat vacuoles in the nuclei and cytoplasma. The histogenesis of this tumor is most likely metaplasia of the fibromuscular component of fatty tissue.