Subtle open-type congenital cholesteatoma should be distinguished from congenital ossicular anomaly -Endoscope assisted microscopic trans canal approach-: Presenting Author: Amiko Ishii. (May 2016) - Ishii, Amiko; Takizawa, Katsumi; Nakanishi, Wakako; Okada, Kazunari; Yamada, Chikako; Monobe, Hiroko