Familial hypocalciuric hypercalcemia type 3 should be considered as differential diagnosis in patients with suspected primary hyperparathyroidism and/or suspected multiple neoplasia syndrome, as correct diagnosis will spare the patients for going through multiple futile parathyroidectomies and for the worry of being diagnosed with a cancer susceptibility syndrome.
Keywords: AP2S1; familial hypocalciuric hypercalcemia type 3; multiple endocrine neoplasia type 1; neuroendocrine tumors; primary hyperparathyroidism.