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 arise from the walls of cystically dilated glandular spaces and project into the lumen. They are variably-sized, have a complex architecture and many have completely hyalinized cores.