It is a truism in otolaryngology that the early diagnosis of an abscess of the brain following infection of the ear is essential toward insuring the best chance of recovery. The prompt recognition of conditions which may simulate this dangerous complication is, for obvious reasons, equally important. When it is borne in mind that the treatment of abscess of the brain, at least after the acute stage, nearly always involves incision or at least aspiration of the collection of pus, it becomes all the more evident that the physician should be on the watch for possible errors in diagnosis, so as to avoid unnecessary traumatization and possible infection of a sterile brain. The following case report illustrates a condition which from this standpoint is peculiarly likely to serve as a pitfall for the otologist. REPORT OF A CASE The patient whose history forms the subject of this paper was a