Nerve sheath myxoma of the oral cavity: case report and review.

Nerve sheath myxoma is a benign peripheral nerve sheath tumor that rarely occurs in the oral cavity; approximately 12 cases have been reported to date. On histologic evaluation the lesions consist of closely aggregated fascicles that vary considerably in cellularity. Some of the lesions are predominantly myxoid with widely spaced, stellate-shaped cells. Other lesions consist of closely aggregated spindle cells in a matrix that appears fibrous yet stains strongly for acid mucopolysaccharides (extracellular mucin). Small numbers of mitotic figures may be observed. Because of their rarity and unusual histologic appearance, it is advisable that the pathologist be familiar with these lesions; they may be mistaken for other myxoid lesions of the oral mucosa. We describe a single case of nerve sheath myxoma that arose in the buccal mucosa in a woman.