Fig. 4

DG somatotrophs represent the predominant component in XLAG adenomas (a GH staining with immunoperoxidase – x10), while neoplastic lactotrophs appear as smaller areas (b PRL staining, immunoperoxidase – x10); some tumor cells express the common α-subunit (c immunoperoxidase – x20); double immunofluorescence for GH (green) and PRL (red) shows lack of co-localization of the two hormones in neoplastic cells (d immunofluorescence – x63)