Chorda tympani schwannoma: one new case revealed during malignant otitis externa and review of the literature

Abstract

This report relates the case of an 89-year-old male patient who presented a chorda tympani schwannoma dis-closed during the management of malignant otitis externa (MOE). To the best of the authors' knowledge, this is the first case in literature with incidental radiological finding of asymptomatic chorda tympani schwannoma

A New Case of Endoscopic Resection of a Chorda Tympani Schwannoma

“…The bone destruction may be caused by tumor compression or factors secreted by the tumor; however, the underlying causes need to be further studied. Magnetic resonance imaging often demonstrates a circular, equal, or low signal intensity in T1WI, and high signal intensity in T2WI, 4,7 in our present case. Although the specific manifestations of chorda tympani schwannoma on CT and MRI are helpful in the diagnosis and understanding of the lesion range and the surrounding anatomical relationship, which is of diagnostic relevance, it is still often necessary for the surgeon to determine the true source of schwannoma through surgery.…”

“…About 25% of schwannomas are reported to occur in areas of the head and neck, 2 but chorda tympani schwannomas are exceedingly rare, with only 12 reported cases in the English literature. 1,4,5 Only 2 cases of chorda tympani schwannoma have been clearly reported in the Chinese literature. 6,7 In this case report, we describe the clinical course of a patient presenting with a chorda tympani schwannoma treated with surgical resection using a transcanal endoscopic approach.…”

An Incidental Chorda Tympani Schwannoma Identified During Middle Ear Surgery

“…Our patient had facial paralysis and purulent ear discharge in presentation, however, we believe such a small tumor was unlikely responsible for the facial paralysis. Due to the slow-growing nature of CTS and compensatory mechanisms, gustatory dysfunction has not been reported ( 2 , 3 , 5 ). As in our case, gustatory dysfunction is rarely appreciated even after complete resection of the nerve ( 2 , 5 ).…”

“…They may contain psammoma bodies. These tumors are EMA positive and S100 negative ( 3 ). In our case, the tumor cells were diffuse and strongly positive with S100; but negative for pan-cytokeratin, chromogranin, and synaptophysin.…”

“…Schwannomas are the most common tumors of the facial nerve in the middle ear cleft. They can arise from any segment of the facial nerve or its branches ( 1 ).Although isolated chorda tympani schwannomas (CTS) are extremely rare, there are several reported cases in the English literature ( 2 , 3 , 4 ). The presented case is an incidental CTS identified during middle ear surgery for chronic otitis media.…”