Head and Neck Schwannomas: 20-Year Experience of a Single Institution Excluding Cutaneous and Acoustic Sites

Abstract

While head and neck sites comprise the most common location of schwannomas, clinicopathologic data regarding those tumors occurring in non-acoustic and non-cutaneous locations are relatively sparse. In this study, therefore, we sought to examine retrospectively the clinical and pathologic features of head and neck schwannomas excised at our institution over a 20-year period. During this period, we identified a total cohort of 85 patients, which included 36 males (42.4 %) and 49 females with average age of 41.3 years, the majority of which presented asymptomatically with a mass. Localized symptoms were, however, associated with all of the schwannomas that arose in the oral cavity and larynx, while tumors within or adjacent to bone were often associated with neurologic complaints (7 of 15 such tumors [46.7 %]). Clinical follow-up data was available in 86.4 % of all cases and demonstrated no recurrences or mortality. Pathologically, the microscopic features were characteristic of those well-described for schwannomas in other sites, including alternating Antoni A and B areas and the presence of degenerative changes. Tumor encapsulation, however, was variable and was completely absent in schwannomas of the nasal cavity, paranasal sinuses, and larynx. Additionally, a significant minority of the tumors (28.2 %) exhibited foci that resembled neurofibroma. Non-acoustic, non-cutaneous schwannomas of the head and neck appear to have clinicopathologic features similar to their soft tissue counterparts with some subsite variation in presentation and/or microscopic features.

Keywords: Nerve sheath tumor; Schwannoma; Sinonasal.

Fig. 1

Plexiform schwannoma from a patient with neurofibromatosis type 2 (a). A schwannoma of the nasal cavity demonstrating lack of encapsulation (b). Schwannoma with neurofibroma-like foci (right side), characterized by coarse collagen bundles in a myxoid background (c). A prominent pseudoglandular space within a schwannoma of the parotid gland with condensation of tumor cells at the periphery of the space (upper left) (d)

Fig. 2

An intranasal schwannoma, which grew as a polypoid mass (a) and lacked a capsule when sectioned (b). A capsule is grossly apparent in this schwannoma excised from a parotid gland (c)