MEN1 and primary hyperparathyroidism: Furthermore, besides a determination based on genetic testing, a diagnosis of MEN1 is made by the presence of at least 2 of the primary MEN1-related manifestations (pituitary adenomas, primary hyperparathyroidism [PHPT], and dpNETs) or at least 1 of the primary MEN1-related manifestations in association with a positive family history of MEN1 in a first-degree relative.