MORPHOGENESIS OF INCLUSION-BODIES OF UROTHELIAL CARCINOMA - A CASE-STUDY

The morphogenesis of inclusions of urothelial carcinoma (K. Donhuijsen et al.: Hum Pathol. 23:860, 1992) is described in a case of a 51-year -old man with poorly differentiated urothelial carcinoma Peritoneal fl uid preparations contained numerous dyscohesive, large, anaplastic cel ls with abundant dense amphophilic cytoplasm often compartmentalized i nto multiple, variably sized, intracytoplasmic lumina, each containing ''bull's eye''-like inclusions, with a periodic acid Schiff-positive refractile central core and an alcian blue/mucicarmine-positive rim Ul trastructurally, the progression of osmiophilic substance from membran e-hound exocrine-type secretory granules, via exocytosis, to a presenc e in both intracytoplasmic lumina and extracellular space has been doc umented Immunohistochemically, the periodic acid Schiff-positive refra ctile cores, as well as the minute periodic acid Schiff-positive granu les in the cytoplasm, stained positively for secretory component and p eanut agglutinins, whereas the alcian blue-positive mucinous material, which coated the refractile cores as well as the lining of the intrac ytoplasmic lumina, stained strongly for epithelial membrane antigen an d leu M1. Ultrastructurally, protein A-gold probes, immunolabeled for peanut agglutinin and secretory component, were localized to the osmio philic substance.