Clear cell carcinomas of the ovary show a variety of architectural patterns and many different cell types admixed in various proportions. The most common patterns are tubulocystic, papillary and solid, often present adjacent to one another. The image shows areas of papillary architecture. The papillary fronds project from the walls of cystically dilated glandular spaces lined by hobnail cells. They are variably-sized, have a complex architecture and may have completely hyalinized cores. This field shows a few psammoma bodies within the papillary cores.