Endolymphatic sac tumors (ELISTs) are rare, locally aggressive tumors that typically arise in the petrous portion of the temporal bone and often present with hearing loss, tinnitus, and vertigo. Here, we report a 57-year-old female presenting with only ear-fullness and a reddish mass in the middle ear, initially suspected as a glomus tumor. Imaging showed no characteristic bone erosion, and it was difficult to diagnose pathologically. Based on clinical evaluation, the diagnosis was made with ectopic ELIST. This unusual case of an ectopic ELIST confined to the middle ear suggests that these tumors can occur outside their conventional location, underscoring the need for their inclusion in the differential diagnosis of middle ear neoplasms and for further research into their pathophysiology and origins.