骨部外耳道拡大と表皮角化物の堆積をきたす病態に関する臨床的研究

抄録

The pathological conditions which cause expansion of the bony external auditory canal and accumulation of keratin debris have been considered to be of two different types. Type I is characterized by the accumulation of keratin debris and the generalized widening of the bony canal and type II by the appearance of a sac-like bone destruction which arises near the tympanic membrane.
During the past three years and ten months, we treated 73 patients with type I and only one with type II. We studied the clinical features and the pathogenesis of these two conditions.
In type I, the epithelial migration on the tympanic membrane and external auditory canal was disturbed to various extents. This disturbance of epithelial migration was proved to be a major cause of the accumulation of keratin debris. Bone resorption was found to be secondary to the accumulation of keratin debris.
Type II is a very rare condition, and it is probable that the accumulation of keratin debris is a sequela of localized sequestrative periosteitis. Therefore, these two types should be strictly differentiated. Our study indicates hat “keratosis with bone resorption”is the suitable nomenclature for type I and, as in the previous literature, “benign necrotic osteitis”for type II.