Jugulo-tympanic paragangliomas are the most common primary neoplasm of
the middle ear.
It is also known as "glomus" tumour or chemodectoma.
Jugulotympanic paragangliomas were first described approximately 75 years ago.
Since that time, there has been considerable evolution in knowledge of tumor biology, methods of classification, and appropriate management strategies.
The tumour is usually located in the middle ear.
The middle ear paraganglioma arise from the paraganglia situated in the wall of the jugular bulb.
Clinical presentation: Usually noted in the 4th to 7th decades of life. Solitary lesions are common in women.
The patient usually presents with conductive hearing loss. There may be pain in the ear, facial palsy, hemorrhage and tinnitus.
Otoscopic examination reveals red vascular mass either behind an intact eardrum or invading it to extend to the external auditory canal.
Macroscopic features: It is a soft reddish tumour.
In the external ear it may extend through eardrum.
In jugular type the petrous temporal bone is infiltrated by the tumour.
In the middle ear space soft tumour extends as far as the tympanic membrane.
The tumour cells form "small clusters" with numerous intervening blood vessels.
Atypical and sometimes multinucleate cells are noted.
Alveolar pattern like in middle ear adenoma has been described.
Neuron-specific enolase, and chromogranin are usually positive.
Sometimes S100 protein positive cells are present. Cytokeratin is negative.
Formalin-induced fluorescence indicate presence of cathecholamine.
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