Figure 7.

Immunohistochemical (immunoperoxidase and hematoxylin counterstain) findings of synchronous primary carcinoid tumor and primary adenocarcinoma arising within mature cystic teratoma of horseshoe kidney. (A) CD56 staining was positive in the carcinoid tumor component. Original magnification ×400. (B) Synaptophysin staining was positive in the carcinoid tumor component. Original magnification ×400. (C) Pancytokeratin staining was focally positive in the carcinoid tumor component. Original magnification ×200. (D) Cytokeratin 20 was negative in the carcinoid tumor component. Original magnification ×200.