PRL and neoplasm: Immunohistochemistry revealed that these tumor cells were diffusely positive for PIT1 (Sigma Life Science, St Louis, MO, USA) (Figure 3C) and focally positive for thyroid-stimulating hormone (TSH; Dako, Glostrup, Denmark) (Figure 3D), GH (Dako, Glostrup, Denmark) (Figure 3E), prolactin (PRL; Dako, Glostrup, Denmark), and estrogen receptor (Novocastra, Leica Biosystems Newcastle Ltd, New Castle, UK).