Clear Cell Carcinoma
Clear cell carcinomas of the ovary show a variety of architectural patterns and many different cell types admixed in various proportions and often present adjacent to one another. The most common architectural patterns include tubulocystic, papillary, and solid. The cell types seen in clear cell carcinomas include (in order of frequency) clear cells, hobnail cells, flattened cells, signet ring, and oxyphilic cells.
This image shows papillary architecture (left half) and solid sheet composed of signet ring cells (right half).