Secondary hypoadrenalism presenting with hypercalcaemia.

We describe a young woman with lymphocytic hypophysitis presenting in the early post-partum period. She had selective corticotroph failure causing secondary adrenal insufficiency. At the time of presentation she had transient hyperthyroidism due to thyroiditis, and hypercalcaemia. This is the third case to be described of hypercalcaemia occurring in association with lymphocytic hypophysitis. Hypercalcaemia is not a recognized complication of other forms of pituitary failure. The two previously described cases also had selective corticotroph failure and hyperthyroidism due to thyroiditis. This pattern of presentation supports the concept that thyroid hormone action in the presence of glucocorticoid deficiency is responsible for the increased calcium efflux from bone into the circulation. Reduced renal excretion of calcium due to a reduction in calcium delivery to the glomerulus and increased proximal tubular reabsorption are also implicated in the aetiology of hypercalcaemia associated with adrenal failure.