A Case of Acquired Pars Flaccida Cholesteatoma Extending to the Supralabyrinthine Petrous Apex With Preservation of the Otic Capsule.

BACKGROUND

Supralabyrinthine petrous bone cholesteatoma is a rare subtype in which hearing preservation may be achievable depending on the anatomical extent and surgical approach. Appropriate selection of surgical strategy is essential.

CASE PRESENTATION: A 31-year-old man presented with a 2-year history of persistent left otorrhea. Otoscopic examination revealed pars flaccida cholesteatoma. Pure-tone audiometry demonstrated hearing loss with an air-bone gap of 35 dB. Computed tomography showed soft-tissue density extending from the tympanic cavity and mastoid air cells to the supralabyrinthine petrous apex. Inner ear function was almost preserved.

INTERVENTION: A staged surgical approach was adopted due to active inflammation. First, canal wall-down tympanomastoidectomy via a transmastoid approach was performed to control infection. Six months later, second-stage surgery was performed using the middle cranial fossa approach for complete removal of the supralabyrinthine cholesteatoma, along with ossicular chain reconstruction.

OUTCOME: No intraoperative or postoperative complications occurred. Postoperative non-echo-planar diffusion-weighted MRI at 4 months showed no residual disease. At 22 months, hearing improved with an air-conduction threshold of 21.7 dB, and no tympanic membrane findings suggestive of recurrence were observed.

CONCLUSION

In supralabyrinthine petrous bone cholesteatoma, selecting the surgical approach based on lesion extent, inflammatory status, and the need for hearing preservation is important for optimizing outcomes. In cases with extensive disease and significant inflammation, a staged strategy incorporating the middle cranial fossa approach may represent a safe and effective option for achieving disease eradication while minimizing the risk of inner ear dysfunction and postoperative complications.