Temporal Bone Cholesteatoma: Typical Findings and Evaluation of Diagnostic Utility on High Resolution Computed Tomography.

Background Pre-operative assessment of middle ear cholesteatoma is a must for assessing the disease's location, extent, and complication, and high-resolution computed tomography (HRCT) is the modality of choice. Therefore, this study aims to assess the common signs of cholesteatoma on HRCT and its diagnostic ability.  Methods Fifty patients with suspected cholesteatoma were considered for the study, which was carried out on an Ingenuity Core 128 slice CT scanner (Philips, Amsterdam, Netherlands). The bilateral temporal bones of 50 patients were assessed for soft tissue density and associated findings. The number of temporal bones with soft tissue density was then correlated with intra-operative and histopathological examinations (HPE).  Results Out of 100 temporal bones, 63 were diseased, and 37 were normal temporal bones. Epitympanum/Prussak's space was the most involved site with soft tissue density seen in 60/63 (95.2%) diseased temporal bones, followed by aditus ad antrum and mesotympanum, which was seen in 51/63 (80.9%) diseased temporal bones. The majority of the soft tissue lesions were non-dependent, accounting for 43/63 (68.2%) of the diseased temporal bones. Bony erosions were seen in 54/63 (85.7%) and bony expansion in 35/63 (55.5%) of the diseased temporal bones. HRCT showed a sensitivity of 100%, specificity of 88.1%, a positive predictive value (PPV) of 92.1%, a negative predictive value (NPV) of 100%, and accuracy of 95% for detection of cholesteatoma.  Conclusion HRCT of the temporal bone precisely demonstrates cholesteatoma's location, extent, and bony changes. Therefore, it has exceptional sensitivity, high specificity, and accuracy in diagnosing cholesteatoma.