SALIVARY GLAND CHORISTOMA OF THE MIDDLE EAR

• Published in: JIBI INKOKA TEMBO Vol. 59; no. 2; pp. 80 - 84
• Main Authors: Nigauri, Natsuki, Komori, Manabu, Otori, Nobuyoshi, Kojima, Hiromi
• Format: Journal Article
• Language: Japanese
• Published: Society of Oto-rhino-laryngology Tokyo 15.04.2016
• Subjects: abonormalities of the ossicles; ectopic salivary gland; mass of the middle ear; salivary gland choristoma
• ISSN: 0386-9687; 1883-6429
• DOI: 10.11453/orltokyo.59.2_80

Choristoma is defined as the presence of a histologically normal tissue in an ectopic location. Salivary gland choristoma is a heterotopic mass of histologically normal salivary gland tissue. Occurrence of a salivary gland choristoma in the middle ear cavity is extremely rare. In most cases, choristoma is associated with other abnormalities of the ossicular chain and facial nerve. We report the case of a patient with salivary gland choristoma, in which the patient was a 5-year-old boy with conductive hearing loss in the right ear. Examination revealed a whitish mass over the anterior and inferior portions of the right TM. Temporal bone CT revealed abnormalities of the ossicular chain. We first suspected congenital middle ear cholesteatoma, and performed exploratory tympanotomy. The operative findings revealed depression of the horizontal portion of the facial nerve with a mass underneath it, and absence of the long crus of the incus and of the stapes super structure. Based on these findings, we suspected facial neuroma, and excised a specimen for histologic study. Then, we could remove the mass. The postoperative course was uneventful, and the facial movements remained normal. Histopathology revealed aggregation of normal salivary gland structures. We then made the final diagnosis of salivary gland choristoma of the middle ear.