Based on the 2022 WHO classification, a pathological examination protocol must include immunostains of the transcriptions factors (Pit-1, T-Pit, and SF-1) for the determination of cell lineage, and then the following stains for possibly associated hormones based on the results of the TF stains: GH, PRL, and TSH for PIT-1-positive adenomas, only ACTH for T-Pit-positive adenomas, and LH and FSH for SF-1-positive adenomas. Here, PRL is linked to adenoma.