Typical cases are as follows: In a patient with craniopharyngioma, GM, and elevated prolactin, the inflammatory breast lesions completely subsided after craniopharyngioma resection and prolactin levels returned to normal, indicating that hyperprolactinemia caused by intracranial lesions may be the direct cause of GM (Nikolaev et al., 2016). This evidence concerns the gene PRL and craniopharyngioma.