Breast cancer in a patient with prolactinoma.

Although the role of prolactin in the initiation and promotion of mammary carcinoma has been proved in animal experiments, a similar effect of hormone in the development of human mammary tumor has not been clearly demonstrated. If hyperprolactinemia is a significant factor in the initiation and promotion of human breast carcinoma, the incidence of mammary carcinoma in patients with hyperprolactinemia, with or without prolactinomas, might be higher than in control populations, but this relationship has never been documented. We present this case to stimulate awareness of the possibility so the condition will be investigated further.