A 68-year-old diabetic man presents with severe otalgia, purulent otorrhoea and granulation tissue at the bony-cartilaginous junction of the external auditory canal. Imaging shows spread of infection to the skull base. Through which anatomical pathways did the infection most likely escape the canal?

• A Fissures of Santorini ✓
• B Petrotympanic fissure
• C Tympanomastoid fissure
• D Huschke's foramen

Explanation

Malignant otitis externa, classically due to Pseudomonas aeruginosa in a diabetic, spreads from the cartilaginous canal through the fissures of Santorini, natural dehiscences in the cartilage of the canal floor, to reach the skull base and temporomandibular joint. The petrotympanic fissure transmits the chorda tympani and lies in the middle ear, not the canal wall.

Reference: Scott-Brown's Otorhinolaryngology and Head and Neck Surgery, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.