Gastric Composite Tumor of Alpha Fetoprotein-Producing Carcinoma/Hepatoid Adenocarcinoma and Endocrine Carcinoma with Reference to Cellular Phenotypes
Figure 3
Immunohistochemistry for AFP-producing adenocarcinoma and neuroendocrine carcinoma. (a) AFP immunostaining in Case 1 (the tubular component of the composite tumor). A positive reaction for AFP is observed in the cytoplasm of the carcinoma cells. The upper side of the photograph shows the tubular and hepatoid components with a positive reaction for AFP, while the lower side shows the neuroendocrine component with a negative reaction for AFP. (b) Chromogranin A immunostaining in Case 1 (NEC component of the composite tumor). A positive reaction for synaptophysin is observed in the cytoplasm of the carcinoma cells. The upper side of the photograph shows the tubular and hepatoid components with a negative reaction for chromogranin A, while the lower side shows the neuroendocrine component with a positive reaction for chromogranin A. (c) CDX2 immunostaining in Case 8 (usual case of AFPC). A positive reaction for CDX2 is observed in the nuclei of tubular adenocarcinoma cells. (d) SOX2 immunostaining in Case 2 (usual case of NEC). A positive reaction for SOX2 is observed in the nuclei of neuroendocrine carcinoma cells. (e) SOX2 immunostaining in Case 1 (the tubular and hepatoid components). A positive reaction for SOX2 is observed in the nuclei of the carcinoma cells. (f) CDX2 immunostaining in Case 1 (NEC component). A positive reaction for CDX2 is observed in the nuclei of the carcinoma cells. (g) Ki-67 immunostaining in Case 1 (NEC component). More than 20% carcinoma cells are positive for Ki-67.