1. H&E satined tumor with solid growth pattern, poorly cohesive tumor cells with relatively large nuclei and eosinophilic cytoplasm; Magnification x200.
2. Some tumor cells are somatotropin-positive; STH IHC; Magnification x200
3. Pancytokeratin-positive fibrous bodies in nearly all tumor cells, AE1-AE3 IHC; Magnification x200; sparsely granulated somatotroph adenoma.
4. Slightly elevated proliferation activity; Ki67 (MIB1) IHC; Magnification x200.