A child with CSOM presents with fever, postauricular pain and ear protrusion. Imaging shows pus extending from the epitympanic recess into the largest air cell of the temporal bone. Through which opening did infection pass?

• A Foramen of Huschke
• B Aditus ad antrum ✓
• C Cochlear aqueduct
• D Petrotympanic fissure

Explanation

The mastoid antrum, the largest mastoid air cell, communicates with the epitympanic recess of the middle ear through the aditus ad antrum, allowing CSOM to spread to the mastoid and cause acute mastoiditis with postauricular swelling and displacement of the pinna. The petrotympanic fissure transmits the chorda tympani and anterior tympanic artery, while the cochlear aqueduct connects perilymph to the subarachnoid space, neither being a route for middle ear to mastoid spread.

Reference: Gray's Anatomy, 42nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.