Endolymphatic sac tumor (ELST) is very rare but its aggressive papillary neoplasm destructs the temporal bone widely and often
involves the intracranial structures. The most effective treatment is complete surgical removal, but it is very difficult because
the character of tumor is very aggressive and extensive to the intracranial region. This tumor is not yet reported in Korea but
we have recently experienced one case of ELST which we treated surgically by the traslabyrinthine/petrosal combined approach.
We report the clinical and histological aspects of this rare tumor with a review of the literatures. (Korean J Otolaryngol
2000;43:996-1000)