An interesting normal variant of the temporal bone.
The purpose of this brief communication is to call attention to a small, rounded bony knob which is infrequently present on the superior margin of the petrous bone. This finding is more often unilateral but may rarely be bilateral. The bony excrescence has the same osseous density as the surrounding dense petrosa from which it arises. Lack of familiarity with this normal variant may lead to the erroneous diagnosis of a petrosal meningioma.
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D011859:Radiography; D013701:Temporal Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging*