Rare case of salivary gland choristoma originating in inner ear in 8-year-old:A report
Salivary gland choristoma (SGCh) is a rare benign tumor reported in several unusual sites, such as the gastrointestinal tract, the optic nerve, and the internal auditory canal, but never reported in the inner ear. It is a rare benign tumor characterized by a histopathological finding of normal salivary tissue, mucous and mixed predilection, and occasionally, fibrosis . SGCh is distinguished from ectopic salivary glands which are present in abnormal locations without fibrous capsules .
In a recent development, a team of doctors under Yoshiharu Yamanobe, have reported an extremely rare case of a large inner ear SGCh extending into the middle ear and the internal auditory canal (IAC), with congenital unilateral profound hearing loss and ipsilateral progressive facial nerve palsy.The case has been reported in Journal of Otolaryngology - Head & Neck Surgery.
The primary sites of SGCh have been reported in several organs, such as the gastrointestinal tract, the optic nerve, and the internal auditory canal . SGCh in the middle ear can sometimes be accompanied by an aberrant facial nerve and middle ear malformations. "We had reasons to consider that the inner ear was the primary site in this case. First, the patient had a congenital profound hearing loss. Second, no previous abnormalities in the tympanic membrane had been detected. Third, imaging studies suggested that the tumor was mainly located in the inner ear."the team elaborated.
An 8-year-old girl with a history of left profound congenital hearing loss presented to the department of Otolaryngology-Head and Neck Surgery, Keio University School of Medicine, Japan, with ipsilateral progressive severe facial nerve palsy (House-Brackmann Grade VI).
Clinical examination revealed the left tympanic membrane was swollen with a pulsatile tumor. Radiological investigations revealed a multilocular tumor in the inner ear extending into the middle ear and internal auditory canal (IAC).
Suspecting a diagnosis of salivary gland choristoma, the team performed a partial resection of the tumor by transmastoid approach to preserve the anatomical structure of the facial nerve. The tumor was pathologically diagnosed as SGCh. Anatomical preservation of the facial nerve was considered significant to retain any chances for recovery of the facial palsy after surger. No intraoperative or postoperative complication such as spinal fluid leakage was observed.
Two years after surgery, her facial function recovered to House-Brackmann Grade II and the residual tumor did not show regrowth on MRI.
"Although the natural course of this rare tumor is unknown, a partial resection is an acceptable treatment procedure when functional recovery of the facial nerve is anticipated."the team of physicians concluded. The residual tumor needs to be carefully monitored in future using MRI, and total removal of the tumor through transotic approach may be necessary if there is an increase in the size of the residual tumor."the team concluded.
For full article follow the link: https://doi.org/10.1186/s40463-021-00511-3
