https://www.selleckchem.com/products/proteinase-k.html To evaluate whether a combined translabyrinthine-transsphenoidal approach can be used to achieve adequate surgical resection of an extensive petrous bone cholesteatoma and create a debris drainage route for the residual cholesteatoma that is maintained long-term. A 71-year-old man with residual petrous temporal bone cholesteatoma that had spread extensively to the internal carotid artery and posterior cranial fossa. Surgical resection of the cholesteatoma via a translabyrinthine approach and creation of a debris drainage route into the nasopharynx via a transsphenoidal approach. Control of unresectable petrous temporal bone cholesteatoma and occurrence of cholesteatoma- or surgery-related complications. Although complete removal of the cholesteatoma was attempted via a translabyrinthine approach, this was not possible because the epithelium of the cholesteatoma was strongly attached to the internal carotid artery and posterior cranial fossa. A debris drainage route leading to the nasopharynx was crea suitable method for keeping cholesteatoma under control in patients with unresectable petrous bone cholesteatoma. Cholesteatoma is an inflammatory disease, frequently observed in childrens and young adults, with a risk of relapse or recurrence. The few studies which analyzed cholesteatoma localization on magnetic resonance imaging (MRI) usually merged CT-MR images or relied on their authors' anatomical knowledge. We propose a compartmental reading method of the compartments of the middle ear cavity for an accurate localization of cholesteatomas on MR images alone. Our method uses easily recognizable anatomical landmarks, seen on both computed tomography (CT) and MRI, to delimit the middle ear compartments (epitympanum, mesotympanum, hypotympanum, retrotympanum, protympanum, antrum-mastoid cavity). We first tested it on 50 patients on non-enhanced temporal bone CT. Then, we evaluated its performances for the localiza