EN4.{7,11} | Squamosal CSOM with Mastoidectomy — Summary & Reflection

KEY TAKEAWAYS

Squamosal (atticoantral) CSOM is the 'unsafe' variant of chronic middle ear disease, characterised by an attic or marginal TM perforation, the presence of cholesteatoma (keratinising squamous epithelium cyst), and a high risk of intracranial and extracranial complications. Cholesteatoma destroys bone through collagenase-mediated osteolysis, eroding ossicles, tegmen, semicircular canals, facial nerve canal, and sigmoid sinus. The three types are congenital (intact TM, no prior ear disease), acquired primary (pars flaccida retraction pocket, Prussak's space — invagination theory), and acquired secondary (marginal perforation with epithelial migration — most common). Clinical features: scanty foul-smelling discharge, progressive conductive or mixed hearing loss, and typically no spontaneous pain until complications develop. Red flags (facial palsy, vertigo, headache, neurological signs) indicate spreading complications requiring emergency treatment. Otoscopy reveals attic crust, attic perforation with pearly-white debris, or granulation tissue. HRCT temporal bone is mandatory: classic findings are scutum erosion and attic soft-tissue density. Management is always surgical: modified radical mastoidectomy (MRM/Bondy) is the most common approach, taking down the posterior canal wall to create an open cavity. Radical mastoidectomy removes all TM and ossicles. Combined approach tympanomastoidectomy preserves the canal wall but requires a second-look operation at 9–12 months. Ossicular reconstruction with PORP or TORP may restore hearing when the stapes remains. Post-operative cavity care (lifelong) and surveillance for recurrence (10–30%) are essential components of the ongoing management.

REFLECT

A 16-year-old girl with recurrent childhood ear infections is referred with an HRCT report showing 'scutum erosion, soft tissue density in the right attic extending into the mastoid antrum, and probable erosion of the long process of the incus.' She has no facial weakness and no vertigo. Her hearing on the right is reduced (PTA shows 45 dB conductive loss). She asks: 'Does this mean I need a big operation, and will I lose my hearing permanently?' Reflect on the following: What operation do you recommend and why, and how do you explain the choice between MRM and combined approach tympanomastoidectomy in terms she can understand? What will you tell her about the risk of recurrence and why she will need lifelong follow-up? How do you counsel her about the realistic hearing outcomes after mastoidectomy, and when might ossicular reconstruction be offered?