Ultrastructural Pathology of the Middle Ear Mucosa in Serous Otitis Media

1. The majority of the “mucoid” ef fusion appears to be the result of secretion of the proliferated epithelium whereas “serous” effusion is an accumu lation of the transudates resulting from increased capillary permeability. 2. The pathologies of both “mucoid” and “serous” types are compatible with that of general inflammation. Unsuspected microbial infections were accounted for in only two cases, and only one case of possible viral origin. In the majority of cases examined, we could not single out any specific cause. There fore, it can be surmised that the in Hammatory reaction caused by various factors is the underlying reason for these effusions.