Ectopic muscle in the middle ear.

An ectopic muscle was found in the hypotympanum of a 31-year-old Japanese male. The muscle produced symptoms quite similar to those seen in cases of glomus jugulare tumor: a red mass visible through the ear drum, conductive deafness, a compressed jugular bulb demonstrable by retrograde jugulography, and VIIth and IXth nerve paresis. However, the audible pulsating tinnitus of glomus jugulare tumor was absent. The mass proved to be a muscle speculated as being a part of the levator veli palatini muscle. In view of our findings, ectopic muscle should be included in the differential diagnosis of glomus jugulare tumor.