Peripheral nerve sheath tumors arising in salivary glands: A clinicopathologic study

•Most salivary gland peripheral nerve sheath tumors arise in the parotid.•Most commonly, they represent neurofibromas.•The neurofibromas are often associated with neurofibromatosis type I.

Primary salivary gland peripheral nerve sheath tumors (PNST) are uncommon. This study is a retrospective, clinicopathologic review of 9 cases of PNST (5 neurofibromas, 3 schwannomas and 1 malignant peripheral nerve sheath tumor (MPNST)) arising from the salivary glands, encountered between 1990 and 2015. All patients with neurofibromas were male (ages 1–62 years) and had a single parotid lesion of which 2 were diffuse, 2 plexiform and one mixed diffuse/plexiform. Four had a history of neurofibromatosis I. Four of 5 presented with symptoms related to mass effect including facial swelling, facial drooping, and dysphagia. All underwent de-bulking surgery and recurred due to continued growth. Of the 3 patients with schwannomas, 1 was male and 2 were female (ages 19, 44 and 56 years). One tumor each arose in the sublingual, submandibular, and parotid glands. Two of 3 presented with soreness and swelling local to the affected gland, especially while chewing. There was no recurrence of these tumors after resection. An MPNST in a male presented as a tender mass in the patient's left parotid; the tumor was resected. There was no evidence of tumor elsewhere in the body. The tumor did not recur in 12 years of follow-up. The most common tumor type in the current series was neurofibroma; most arose in the background of neurofibromatosis type I and all of which recurred after initial subtotal resection. Most PNST arose in the parotid gland.