A 60-year-old presenting with complaints of hard of hearing and recurrent episodes of left sided headache.
A 60-year-old presented with complaints of hard of hearing and recurrent episodes of left-sided headache.
- HRCT and Contrast Temporal bone imaging demonstrate moderately enhancing, smooth, soft tissue mass in left external auditory canal.
- HRCT reformatted bone window demonstrates permeative destruction of mastoid bone inferior to inferior wall of external auditory canal, destruction and widening of mastoid part of left facial nerve canal, and widening of stylomastoid foramen.
- Rarefaction of the lateral wall of the left jugular foramen, with the intact jugular spine.
- The left tympanic membrane is intact.
- No soft tissue in the left middle ear cavity.
DIAGNOSIS AND DISCUSSION:
- Soft tissue mass in the left external auditory canal, with the erosion of underlying bone.
- In view of absent soft tissue in the middle ear cavity and intact jugular spine, diagnosis of Paraganglioma of left external canal was considered, likely arising from Arnold’s nerve (branch of the vagus nerve).
- The patient underwent surgical resection and HPE was suggestive of paraganglioma.
Discussion:
- Paragangliomas are benign neuroendocrine tumors originating from paraganglia rests.
- In the ear, paragangliomas are commonly found in the middle ear (glomus tympanicum) or jugular bulb (glomus jugulare).
- Glomus jugulare – Erosion of the caroticojugular spine between the carotid canal and jugular fossa may be present (Phelp sign).
- Glomus tympanicum – soft tissue mass in middle ear cavity, lateral to cochlear promontory.
- Paragangliomas of the external auditory canal (EAC) are extremely rare and are related to paraganglia rests present in the Arnold’s nerve.
- This may be misdiagnosed as a polyp.
REFERENCES:
- Renu S Rajguru, Shruti Anil Sharma, Ritu K Mehta, Inderdeep Singh. Paraganglioma of the external auditory canal: A rare entity. Published Online Jun 19, 2019. doi: 10.4103/indianjotol.indianjotol_131_18
- Hyo-Seok Seo, Sung-Won Choi, Soo-Keun Kong, Eui-Kyung Goh. Paraganglioma of the External Auditory Canal: A Case Report. J Clinical Otolaryngol 2017;28:234-237
- Liam JS, Aongus JC, Colma B, Conrad IT. Paraganglioma of the external auditory canal: an unusual case. Published Online Mar 08, 2006. doi.org/10.1258/0022215001905599.
Dr Anita Nagadi MD, MRCPCH, FRCR
Senior Consultant Radiologist
Columbia Asia Radiology Group.
Dr. Diwakar C
Radiology resident
Columbia Asia Referral hospital.
