Keratosis obturans

Case contributed by Dr Dalia Ibrahim

Presentation

Right conductive hearing loss. Clinical otoscopic examination revealed a right aural polyp.

Patient Data

Age: 50 years
Gender: Male
CT

Right external auditory canal intra-luminal soft tissue density extending laterally from tympanic membrane. Note absence of underlying bony changes. The middle ear and osicular chain are not involved.

Left external auditory canal small soft tissue density showing internal air loculi representing external auditory canal debris.

Small opacification of the right mastoid air cells.

 

Case Discussion

Pathology revealed "Keratosis obturans"

Gross:

1 - soft tissue polyp in external auditory canal: Membranous tissue pieces, 1x1cm,totally submitted

2 - granulation tissue in external audtory part of external auditory canal: very tiny tissue portion.

MICROSCOPIC:

Examination of the specimen (1) received fragments of cyst wall lined by keratinized squamous epithelium and filled with keratin,specimen (2) revealed tiny fibrous stripe with minimal inflammatory cell infiltration.

No specific granuloma or atypia in sections examined.

Keratosis obturans is a rare external auditory canal (EAC) disease characterized by abnormal accumulation and consequently occlusion and expansion of the bony portion of the EAC by a plug of desquamated keratin.

Differential diagnosis

  • External auditory canal debris, which are partially filling the EAC and usually show air foci
  • External auditory canal cholesteatoma: EAC soft tissue density with bony erosion
  • External auditory canal carcinoma: irregular mass with or without bony erosion
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Case information

rID: 63538
Published: 8th Oct 2018
Last edited: 9th Oct 2018
System: Head & Neck
Inclusion in quiz mode: Included

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