[An unrecognised cause of hypercalcaemia: hypercalcaemia-hyocalcluria syndrome]

A 32-year-old man with insulin-dependent diabetes secondary to chronic calcifying pancreatitis of alcoholic origin in whom hypocalciuria (22 to 88 mg/24 hours) was discovered by chance, renal function being normal. Plasma phosphate levels were between 25 and 35 mg/l and the level of parathyroid hormone was at the upper limit of normal. Cervicotomy led to the discovery of three parathyroid glands which were removed. Their weight was increased and their histological appearance normal. The fourth parathyroid was not seen. Hypercalcaemia and hypocalciuria were found during the operation and persis 3 years after, with none of the usual causes being found. This patient has a certain number of characteristics reminiscent of familial hypercalcaemia-hypocalciuria syndrome: high plasma calcium levels associated with low calciuria despite normal renal function and a plasma parathyroid level normal in most cases. The physiopathology of this syndrome remains unknown. Its course is benign, without renal complications. Partial parathyroidectomy is ineffective.