Tympanomastoid cholesteatoma has no accepted staging or scoring system up till now. Many classifications/staging were adopted worldwide; yet, failed to gain acceptance.
We adopted a newly designed, objective, broad, decisive scoring system for all types of tympanomastoid cholesteatoma that focused on the basic biologic behavior of this serious disease to cover all the black spots in the previous scoring and staging systems.
Our scoring system relied on clinical, CT findings, and confirmed with intraoperative findings. All bony items in the tympanomastoid area that could be affected by cholesteatoma were scored in an ascending scale from 0~3, including: scutum (S), ossicles (O), mastoid air cells (M), posterior bony canal wall (C), lateral sinus plate (L), inner ear structures (E), facial nerve canal (F), and tegmen (T). These items called collectively SOM CLEFT scoring system. Cranial and intracranial complications were included as the highest score for each bone specifically.
According to this scoring system, we could stage cholesteatoma into 5 stages:
Stage 0: CIS (Cholesteatoma in situ) = S0O0 cholesteatoma i.e. cholesteatoma confined to the ME cavity with no evidence of bone erosion
Stage I: S0-1O0-3 cholesteatoma i.e. cholesteatoma confined to the ME cavity with evidence of limited bone erosion of the scutum and /or ME ossicles
Stage II: M1C1 cholesteatoma i.e. cholesteatoma that extend to the mastoid with erosion of mastoid air cells with or without canal wall erosion
Stage III: M2-3C2L1E1-2F1-2T1 cholesteatoma i.e. cholesteatoma with cranial complications with or without tegmental erosion and sinus plate erosion
Stage IV: L2-3E3F3T2 cholesteatoma i.e. cholesteatoma with intracranial complications with or without labyrinthitis and/or complete facial nerve paralysis