Chronic otomastoiditis with ossicular erosions

Chronic otomastoiditis with ossicular erosions, also known as non-cholesteatomatous ossicular erosions or post-inflammatory ossicular erosions, is defined by the erosive changes involving the middle ear ossicles in the absence of cholesteatoma in a patient with a history of chronic otomastoiditis.

Radiographic features

Normal anatomy of the ossicular chain should be checked to confirm the diagnosis:

  • ice cream cone configuration in the epitympanum: in the disease erosion of the cone (incus body/short process) may occur
  • two parallel lines in mesotympanum: erosive changes occur in the posterior line (incus lenticular process, incudostapedial joint and stapes head)
  • in coronal CT: erosions occur in the vertical segment of the right angle (long process of incus)  
  • tympanic membrane usually is thick and retracted

Differential diagnosis

  • congenital/acquired cholesteatoma with ossicular erosions
  • post-operative ossicular loss (associated with mastoidectomy)
  • post-traumatic ossicular dislocation

See also