Neurothekeoma of the Oral Cavity: Report of two cases of a distinctive variant and review of the literature

Neurothekeoma (NT) including nerve sheath myxoma (NSM), is a benign neoplasm derived from the peripheral nerve sheath that occurs very rarely in the oral cavity. We describe two cases of a distinctive variant of NT arising in the buccal mucosa and the tongue. Histologically, one of the lesions showed the coexistence of ill-circumscribed hypocellular and myxoid lobules and hypercellular fibrous fascicles, and the other demonstrated a scattered distribution of the tumor cells in myxoid matrix in various sizes of nests. These findings, together with immunohistochemical characteristics, suggest that the former lesion is a mixed variant of NT, and the latter is a myxoid variant of it. A review of the literature revealed 16 previous reports of NTs arising in the oral cavity.