Large intraparotid facial nerve schwannoma: report of a case with radiological-pathological correlation and surgical approach

Abstract Background Schwannomas are benign, slow-growing tumors arising from Schwann nerve sheath cells and affecting the peripheral and cranial nerves. Twenty to 40% of all schwannomas involve the head and neck region. Facial nerve schwannomas are rare and tend to occur in the infratemporal part of the nerve. Intraparotid facial nerve schwannomas involving the deep lobe of the parotid are uncommon. Case presentation A 72-year-old woman was admitted to our maxillofacial surgery clinic with a mass in the left retromandibular region. The patient underwent an MRI examination that showed a sizeable well-circumscribed lesion affecting the deep lobe and the inferior part of the left parotid gland and a CT scan without contrast injection to evaluate the stylomastoid foramen and the facial nerve canal. The patient underwent a parotidectomy without sparing the facial nerve. Histopathological examination showed a biphasic neoplasm with spindle cell areas arranged in fascicles with striking palisades resulting from stacked nuclei alternating with anucleate zones. Conclusions Intraparotid facial nerve schwannoma (IFNS) is a rare entity. Although radiological diagnosis represents a challenge, the presence of some radiological signs, morphological characteristics, and the typical intensity signal in MRI could be beneficial for preoperative diagnosis and treatment. This case report will discuss the radiological-pathological findings and surgical management of a large intraparotid facial nerve schwannoma.