The pathogenesis of the association of medullary sponge kidney and hyperparathyroidism from parathyroid adenoma remains obscure. This unusual case of medullary sponge kidney and secondary hyperparathyroidism due to renal-leak hypercalciuria gives insight into a possible mechanism for the occurrence of medullary sponge kidney with parathyroid adenoma. Suppressible hyperparathyroidism due to renal calcium wasting could represent an intermediate stage in the development of unsuppressible parathyroid hormone secretion. Thus, parathyroid adenoma occurring with medullary sponge kidney may represent a consequence of disordered renal calcium excretion rather than a primary abnormality.
(JAMA 241:1490-1491, 1979)