[Middle ear adenoma. Long-term course of a rare neoplasm]

[A rare pathology of the petrous part of the temporal bone: adenoma of the middle ear]

Adenomas are very rare tumors of the middle ear. They are benign neoplasms originating from the glandular components of the mucous membrane of the middle ear. The middle ear adenoma was first described by Hyams and Michaels in 1976, which was named an adenomatous tumor. This article reports the case of a 50-year-old female patient, who presented with recurrent right-sided dull otalgia and pulse synchronous tinnitis, which began 1 year prior to presentation, with the suspected diagnosis of a glomus tympanicum tumor. Following the otorhinolaryngological examination and imaging an unclear mesotympanal space-occupying lesion was detected. A transmeatal endoscopic complete removal of the tumor was carried out. The histopathological investigations enabled the diagnosis of an adenoma of the middle ear. Adenomas are a rare differential diagnosis of tumors of the middle ear. In cases with a suitable localization an adequate exposure and removal of this rare tumor can be achieved by a transmeatal endoscopic access.

Ultrastructural morphology of a middle ear ceruminoma

The ultrastructural morphology of a ceruminous gland adenoma in the middle ear was examined electron microscopically. The epithelial tumor cells displayed apocrine caps, microvilli, cell junctions, secretory granules, vacuoles, lipid droplets and siderosomes, which are the characteristic ultrastructural features of apocrine glands. Concentric membranous bodies of the endoplasmic reticulum, phagocytic activity of the tumor cells, intracytoplasmic lumina, ciliated cells and also spiny collagen in the tumor stroma could be seen. The myoepithelial cells are an important tumor marker in the differential diagnosis between ceruminomas and adenomas of the middle ear. The ectopic origin in the modified apocrine ceruminous glands, the specific localization, the clinical features and the extremely rare occurrence of the ceruminoma makes this tumor a unique neoplastic entity.