ENT 2019: Auricular schwannoma: a case report

Schwannoma is a benign tumour of schwann cells and is seldom to be seen in the auricle. In the literature, very few cases of schwannomas originating in the pinna were reported. In this article, we described a 35-year-old female patient who presented with right painless auricular mass which was treated by excision under general anesthesia. The clinical and histopathologic features, the differential diagnosis, and the treatment of auricular schwannomaare discussed. Key words: auricle,schwannoma, Iraq. Introduction: Schwannomasare slowly growing benign tumour of neuro-ectodermal origin. Schwannomas are well known to arise from schwann cell of the branches of peripheral, cranial or autonomic nerves. They are usually presented as a painless solitary swelling. They are affecting the head and neck in a 25-45%, where the vestibular schwannoma is the commonest. The presentation of head and neck schwannomas depends on their location. Auricle is a rare site of affection by schwannoma (1). The first case of external ear schwannoma was reported in 1977 (2). When we were reviewing the literatures, only five cases of auricular schwannomas were reported in the world (1- 5). In the present article we describe a further case of auricular schwannoma. Case report: A 35 year old female was presented to the outpatient ENT clinic in AL-Hussein teaching hospital/ Samawah city with painless swelling over the posterior aspect of the right auricle (Figure 1) 2 years ago, the swelling is gradually increasing in size. There is no history of previous trauma or surgery. No other ear, nose and throat or general symptoms. The mass is non-tender, oval in shape, measured 5ₓ3 cm. in diameters, freely mobile, fluctuant and the overlying skin is warm on touch and there is an increased in its vascularity. There is no scar and no changes over the skin surrounding the swelling. The swelling is neither pulsatile nor compressible.Other ear, nose, and throat examination were completely normal. We put the sebaceous cyst, epidermoid cyst, lipoma,haemangioma, and keloid as a differential diagnosis for such mass. The mass was easily excised completely under general anaesthesia and sent for histopathological examination. Grossly the mass is an oval in shape, 5ₓ3 cm in diameters, when we excised part of it, its cavity contains a blood with a thick wall but it contains no hair (Figure 2). The histopathological result showed the diagnosis of auricular schwannoma (Figure 3). The tumour cells were stained strongly for S-100 protein on immunohistochemical staining. The final diagnosis of the mass was established as auricular schwannoma. There is no recurrence during a 3 years follow-up.This study was approved by scientific team of AL-Hussein Teaching Hospital in Sammawah city/Iraq. Figure 1: The patient with right auricular mass. Figure 2: The excised mass contains a blood with in its cavityand has a thick wall. Figure 3: Microscopic section of the tumor showing areas ofcompact spindle cells arrayed in a palisade pattern known asAntoni type A, Antoni type B, Verocay bodies and an area of hemorrhage within a cavity. (H&E staining, A: 40× and B: 4× magnification power) Discussion: Verocay in 1908 was the first who describe the solitary schwannoma and gave it the name of neurinoma; the name schwannomawas assigned by Batsakis in 1974. Schwannoma is also known by other terms, such as neurinoma, neurilemmoma, mioschwannoma, schwannoglioma, etc (6).The first case of auricular schwannoma was reported by Fodor et al in 1977.Following this case only 4 cases were reported in the world (1-5). Schwannoma is a slowly growing, painless, benign, encapsulated tumourarising from schwann cell, so any nerves could be affected by this kind of tumour except the olfactory and optic nerves.Affection of the external ear by schwannoma is extremely rare (7). The nerve supply to the auricle are derived from auriculotemporal, greater auricular, lesser occipital and partly from facial and vagus nerves (1). Owing to the location of the presenting case, the swelling may have originated from the branch ofgreater auricular nerve. Due to its rarity occurrence, auricular shwannoma is rarely put in the differential diagnosis of the swelling of the pinna. The final diagnosis of the schwannomadepends on histopathological evaluation and immunohistochemical study.The treatment of choice for such tumour is by complete surgical excision. The recurrence is rare after complete surgical removal (7). Conclusion: Despite auricular schwannoma is extremely rare tumour, it should be considered in the differential diagnosis of a benign looking swellings of the pinna.

Author(s): Raid M. AL-Ani*, HaidarKhudairAbd

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