Fig. 4.

GH producing (cell) adenoma (GHoma). The tumor cells of hematoxylin eosin (H&E) staining (a). In IHC, it shows many GH positive tumor cells (b), frequently cells are also positive for PRL (c) and αSU (d). The IHC of pituitary-specific transcription factor 1 (Pit-1), which regulate the functional differentiation of GH–PRL–TSH cell lineage (e). In electron microscopy, many GHoma are type of densely granulated cells, which contain many dense cored numerous secretory granules (f). SSTR2a is immunostained in cell membrane (g), which provides important information for SSAs therapy