“Ancient” schwannoma of the submandibular gland

Abstract

Rationale:Schwannomas are solitary neurogenic tumors that arise from cells of the neural sheath. Ancient schwannoma is a relatively rare variant of schwannoma, characterized by increased cellularity and atypia. These cellular changes could be confusing and make the accurate pathologic diagnosis difficult.Patient concerns and diagnoses:A 36-year-old man presented with painless swelling in left submandibular region for more than 2 years. The computed tomography confirmed a well-defined cystic lesion in the left submandibular space, which caused superior and posterior displacement of the left submandibular gland. Surgical excision was performed and the pathology confirmed the diagnosis of ancient schwannoma. To our knowledge, this patient is the second case of primary submandibular ancient schwannoma reported in the literatures.Interventions and outcomes:The patient underwent tumor resection and postoperative recovery was uneventful. There were no nerve deficits after the operation. There was no recurrence within 1 year of follow-up.Lessons:Schwannoma originated from the submandibular gland is extremely rare and only a few cases have been reported. Ancient schwannoma is an even more rare tumor. The increased cellularity and atypia of ancient schwannoma can resemble features of malignancy. Great care must be taken to make differential diagnosis with fibrosarcomas and malignant schwannoma.

Ancient schwannoma in the right iliac fossa: A case report and review of literature

“…Ancient schwannomas, first described by Ackerman et al. in 1951, are a rare variety of schwannomas, which are benign tumors that arise from Schwann cells in the peripheral nervous system [ 1 , 3 ]. Ancient schwannomas have been reported in various regions of the body, most commonly in the head and neck region [1] .…”

“…Histologically, ancient schwannomas are characterized by encapsulated regions with atypia and nuclear hyperchromatism, and as they grow larger, they may demonstrate various degenerative changes such as cystic degeneration and hemorrhage, all of which may be confused with malignant neoplasms, such as sarcoma [ 1 , 3 ]. These degenerative changes contribute to the growth and aging of the tumor, hence termed ancient schwannoma [11] .…”

“…Typically, they are known to be solitary, encapsulated, and slow growing [2] . Ancient schwannomas, an uncommon variety of schwannoma, exhibit unique histopathological changes including spindle cells with Antoni A and B fibers, with areas of degenerative changes, such as calcification, hyalinization, and cystic necrosis [3] . These features could be confused with malignancy leading to an inaccurate diagnosis [1] .…”

Unmasking Hypoglossal Nerve Schwannomas Mimicking Submandibular Salivary Gland Tumors: Case Report of a Rare Presentation and Surgical Management

“…Schwannomas exhibit several histological subtypes: ancient, microcystic-reticular, epithelioid, cellular, psammomatous, and melanotic [14]. Histopathologically, submandibular schwannomas typically demonstrate a biphasic growth pattern comprising densely aggregated spindle cells (Antoni A) and areas of looser, disorganized cells (Antoni B) [4].…”