一側頭骨標本にみられた球形嚢内の特異な膜条構造

抄録

A few pathoses of the otolithic membrane have so far been morphologically con-firmed. We recognized a supposed abnormal otoconial membranous structure in a specimen of the right temporal bone of a 77-year-old woman who died of mucoepidermoid carcinoma of the parotid gland. A report is made here of this case. The abnormal membranous structure was observed in the sacculus, a partial wall of which has formed a membrane in such a manner as makes up a fold from rear to front. The structure is 25 μm thick and a quasi-transparent layer is covered on its both sides with a flat layer of cells. A particle of about 10 μm in long diameter was seen in the quasi-transparent layer. We presumed the particle to be otoconia. Its functional rela-tionship is not obvious in the absence of the patient's complaint of disequilibrum. Neither period nor mechanism of its pathogenesis is known.