Fig. 4

Comparison of the two tumor components in morphology and IHC staining, × 200. Hematoxylin and eosin staining of two tumor cells (a Pheochromocytoma, b Metastatic breast carcinoma). CD56 is expressed on the membrane of pheochromocytoma cells (c Pheochromocytoma, d Metastatic breast carcinoma). CgA is diffusely expressed in pheochromocytoma (e Pheochromocytoma, f Metastatic breast carcinoma). SYN is also diffusely expressed in pheochromocytoma cells (g Pheochromocytoma, h Metastatic breast carcinoma). S100 is expressed in the sustentacular cells of pheochromocytoma (i Pheochromocytoma, j Metastatic breast carcinoma). CK is stongly positive in metastatic breast cancer cells (k Pheochromocytoma, l Metastatic breast carcinoma). HER-2 is stongly positive (3+) in metastatic breast cancer cells (m Pheochromocytoma, m Metastatic breast carcinoma). E-cadherin is membrane positive in metastatic breast cancer cells (o Pheochromocytoma, p Metastatic breast carcinoma). The proliferative index (Ki67) of pheochromocytoma is not more than 10% (q) and that of metastatic breast cancer is about 70% (r). GATA-3 is weakly positive in pheochromocytoma cells (s) and significantly positive in metastatic breast cancer cells (t)