Figure 5:

Eosinophilic solid and cystic (ESC) renal cell carcinoma (ESC case #3, 28 year old female). The neoplasm demonstrated solid and cystic architecture (A). On higher power magnification one can appreciate the eosinophilic cytoplasm of the neoplastic cells, as well as multinucleate cells lining the cysts (B). At high power, one can appreciate the precipitated, clumped cytoplasm characteristic of this neoplasm (C). The neoplasm demonstrates patchy immunoreactivity for cytokeratin 20, accentuated in the cyst lining (D).