Myxoma of the mandible--a fibroblastic tumor.

A case of myxoma of the mandible is described. The tumor was examined by both light and electron microscopy. Histochemistry showed an abundant acid mucopolysaccharide stroma, embedded in which were stellate cells with branching processes. Ultrastructurally, these cells were seen to be fibroblasts. Occasional myofibroblasts were seen in the tumor. No odontogenic epithelium was identified, and this component was not thought to be important in the histogenesis of the tumor.