A case of hypocalciuric hypercalcemia without family history

Familial hypocalciuric hypercalcemia (FHH) is usually characterized by asymptomatic hypercalcemia, mild hypermagnesemia, and low urinary calcium excretion, and is occasionally associated with pulmonary fibrosis. It is inherited as an autosomal-dominant, and no sporadic case of hypocalciuric hypercalcemia has been heretofore reported. This report describes a patient with hypocalciuric hypercalcemia completely compatible with FHH but with no family history, suggesting that the most likely diagnosis is "nonfamilial" hypocalciuric hypercalcemia. We propose that the urinary excretion of calcium be examined in all patients with hypercalcemia, hypophosphatemia, and increased PTH before neck surgery, even if patients have no family history of hypercalcemia.