Non-papillary carcinoma in situ of the urinary bladder. An electron microscopic study.

A case of non-papillary carcinoma in situ of the urinary bladder was presented with ultrastructural descriptions. Dysplastic urothelial cells had a large nucleus with prominent nucleoli and increased euchromatin. The nuclei had a wavy outline with irregular invaginations. Cytoplasmic organella were immature and fairly good amount of glycogen particles existed in the cytoplasm. Among the dysplastic cells, there are two types of epithelium, one which has irregular pleomorphic cytoplasmic processes and the other which has relatively smooth cell borders. Both types had few poorly developed desmosome-like cell attachments and wide intercellular space. This study revealed that decreased numbers of desmosome-like attachments and wide intercellular space with or without cytoplasmic processes of non-papillary transitional cell carcinoma of the urinary bladder might be a morphologic expression of loss of cohesiveness in this type of carcinoma.