Multiple schwannomas with pseudoglandular element synchronously occurring under the tongue: A case report

BACKGROUND: Schwannoma is a rare benign, encapsulated tumor of the nerve sheath under the tongue, mostly occurring as solitary tumors with classical histological pattern and several common morphological variants. To our knowledge, multiple schwannomas with pseudoglandular element synchronously occurring under the tongue are rare; we report herein the first such case. CASE SUMMARY: A 53-year-old man had first noticed an isolated asymptomatic mass under the tongue, and as the mass grew, the tongue was elevated. Physical examination showed multiple oval neoplasms, and the overlying mucosa was normal. Computed tomography showed three low-density oval neoplasms under the tongue, which were cystic-solid with unclear boundary. The patient has no cutaneous tumors, VIII nerve tumors, or lens opacities and no history of neurofibromatosis 2 or confirmed schwannomatosis in any first-degree relative. Magnetic resonance imaging showed no evidence of vestibular schwannoma. The preoperative diagnosis was mucoepidermoid carcinoma. During hospitalization, all neoplasms were completely excised by surgeons through an intraoral approach under general anesthesia. The diagnosis of the multiple schwannomas with pseudoglandular element was made by histopathology after surgery. At the 15-mo follow-up visit, the patient had no sign of recurrence or development of other peripheral nerve tumors. CONCLUSION: Although rare, multiple schwannomas with pseudoglandular element do exist in patients presenting with masses under the tongue. Oral surgeons should be aware of the existence of multiple schwannomas with pseudoglandular element when considering masses under the tongue due to the different prognosis between multiple schwannomas with pseudoglandular element and mucoepidermoid carcinoma.