Erosions of the petrous temporal bone

Primary mucocele of the mastoid: An incidental finding

“…Differential diagnosis of lesions causing erosion of the temporal bone includes inflammatory lesions such as cholesterol granuloma or cholesteatoma, extracranial cysts like epidermoid or dermoid cysts, intracranial lesions such as epidermoids or subarachnoidal cysts, histiocytosis, lymphoproliferative disorders, and solid tumors like schwannomas, tympanic‐jugular paragangliomas, meningiomas, gliomas, giant cell tumors, osteomas, ossifying fibromas chordomas, and primary or metastatic carcinomas …”

“…12 Differential diagnosis of lesions causing erosion of the temporal bone includes inflammatory lesions such as cholesterol granuloma or cholesteatoma, extracranial cysts like epidermoid or dermoid cysts, intracranial lesions such as epidermoids or subarachnoidal cysts, histiocytosis, lymphoproliferative disorders, and solid tumors like schwannomas, tympanic-jugular paragangliomas, meningiomas, gliomas, giant cell tumors, osteomas, ossifying fibromas chordomas, and primary or metastatic carcinomas. 2,11,13 Adequate radiological assessment is based on CT and MR. Complete opacification, an enlarged cavity with bony defects, and sometimes peripheral calcifications and possible peripheral enhancement, if a contrast agent is administered, are the features seen by CT. 2,11 The MR signal is variable according to the proportions of water, mucus, and protein: A low signal in water-rich content and high signal in protein-rich content is evident in T1-weighted images, a high signal in water-rich content, and a low signal in protein-rich content in T2-weighted images.…”