Myxoma of the jaws with an unusual intracellular banded structure.

Myxoma of the jaw is a rare odontogenic tumor, probably derived from the dental apparatus. The case described here was studied by both light and electron microscopic methods. Stellate cells with branching processes were reported in an abundant acid mucopolysaccharide stroma, and ultrastructurally these cells were seen to be fibroblast. Occasionally myxoblasts and macrophages were reported in the tumor. No odontogenic epithelium was identified, while an intracellular synthesis of cross-striated fibrils was observed. The ultrastructural features suggest that the connective tissue cell is the proliferating component of the tumor and is very similar to a fibroblast.