Given the multi-glandular nature of parathyroid involvement in MEN1, preoperative imaging to localize the parathyroid tumors, such as ultrasound of the neck, Tc99m-sestamibi parathyroid scintigraphy, or chest computed tomography (CT), is of limited value, with the exception of possible use in cases of recurrent or persistent PHPT. This evidence concerns the gene MEN1 and tumor of parathyroid gland.