Table 3. University of Pittsburg staging system proposed by Arriaga et al. for the external auditory canal [67, 68].

 

T- Status            Description

T1                             Tumor limited to the external auditory canal without bony erosion or evidence of soft-tissue extension

T2                             Tumor with limited external auditory canal bony erosion (not full thickness) or radiographic finding consistent with limited (<0.5 cm) soft tissue involvement.

T3                             Tumor eroding the osseous external auditory canal (full thickness) with limited (<0.5 cm) soft-tissue involving middle ear and/or mastoid, or patients presenting with facial paralysis

T4                             Tumor eroding the cochlea, petrous apex, medial wall of middle ear, carotid canal, jugular foramen or dura, or with extensive (>0.5 cm) soft-tissue involvement

N-status              Involvement of lymph nodes is a poor prognostic finding and Automatically places the patient in advanced stage (i.e., Stage III [T1, N1] or Stage IV [T2, T3, T4, N1] disease)

M-status             Distant metastasis indicates a very poor prognosis and immediately places the patient in the stage IV category. In the absence of metastatic lymph nodes or distant metastases, T-status defines the overall clinical stage of the patient.