Squamous cell carcinoma of the middle ear: report of three cases.

Squamous cell carcinoma of the middle ear (SCCME) accounts for 1.5% of malignant tumors in the ear. Because of the low incidence and infrequent reports of SCCME, the extent of concordance between CT and MRI results, surgical findings, and pathology reports are not well-characterized. In the present study, we reported CT and MRI images in three SCCME cases, and assessed the relationship between these results and those of surgery and the pathological report. Middle ear carcinoma is frequently misdiagnosed before surgery. In three cases of middle ear carcinoma, CT revealed the following: 1) soft tissue density lesions centered around the middle tympanum, exhibiting increased density, with external auditory canal involvement; 2) damage and absorption in the mastoid area, ossicles, and facial nerve canal, characterized by an irregular, worm-eaten appearance, without sclerotic margins; and 3) lesion infiltration of the surrounding bony substance of the middle ear, temporal squama, temporomandibular joint, anterior wall of the sigmoid sinus, and horizontal segment of the canalis caroticus (in one case lesion invasion into the intracranial cavity occurred through sigmoid sinus walls; no signs of intracranial invasion were seen in the other two cases). Enhanced lesion imaging revealed partial heterogeneous enhancement. In one patient MRI revealed a defined mass in the mastoid area of the middle ear. Signals in the lesion were partially heterogeneous and similar to brain tissue in T1- and T2-weighted images. The lesion was significantly enhanced following application of a contrast agent, while the adjacent meninges also exhibited linear enhancement. No abnormal signals were detected in the brain parenchyma. The destruction of adjacent bone plates was poorly defined. The CT and MRI results were consistent with the invasive features of middle ear cancer documented in the post-surgery pathology report.