A study of vesical adenocarcinoma, intestinal metaplasia and related lesions using mucin histochemistry.

Biopsy and autopsy material from the urinary bladder was studied using PAS and PAS-D techniques to identify glycogen and neutral mucins, the alcian blue/high iron diamine method to distinguish sialo- and sulphamucins and the PB/KOH/PAS technique to localize O-acylated sialomucins. All of 10 examples of normal urothelium and both of two cases of transitional carcinoma in situ contained glycogen, but no mucin. Other lesions displayed one of two patterns of mucin production: the extracellular mucin seen focally in 17 cases of cystitis cystica consisted of sialo- and/or neutral mucins only, a pattern also displayed by mucins produced in 10 of 13 examples of transitional cell carcinomas and by three of nine tumours purely or in part adenocarcinomas. The intracellular mucins expressed in five of the 17 cases of cystitis glandularis and in all of eight cases of frank intestinal metaplasia with goblet cells displayed a colonic phenotype, with production of O-acylated sialomucins. A similar profile was expressed by six adenocarcinomas and this included tumours likely to be of vesical and also of urachal origin. It is concluded that identification of O-acylated mucins cannot distinguish between primary bladder tumours and metastases from a colonic primary, or between carcinomas of vesical and urachal origin.