However, in some cases, patients clinically diagnosed with MEN1 may be genotype-negative.<h4>Case presentation</h4>A 56-year-old female was diagnosed with MEN1 based on a macroprolactinoma (19 mm in diameter), primary hyperparathyroidism, and a cortisol-producing adrenal adenoma, without a family history. The gene discussed is MEN1; the disease is primary hyperparathyroidism.