[A 63-year-old patient with worsening general condition, bone demineralization, hypocalcemia and excess parathyroid hormone: late manifestations of pseudohypohyperparathyroidism].

HISTORY AND CLINICAL FINDINGS: A 63-year-old man was hospitalized because of his worsening general condition and weight loss. Physical examination revealed marked thoracic kyphosis with impaired mobility of his back and restricted walking because of pain in the right hip. He also had other bone pains.

INVESTIGATIONS: Serum calcium was reduced (1.60 mmol/l) and there was generalized bone demineralization. Subsequently an increased parathormone (PTH) level was noted (499.0 ng/l) as well as markedly increased activity of enzymes involved in bone metabolism, decreased renal excretion of phosphates (4.76 mmol/24 h) and multiple pathological fractures.

TREATMENT AND COURSE: The listed abnormalities indicated the diagnosis of pseudohypoparathyroidism (PHP), type 1 b. After treatment had been started with vitamin D (calcitriol 2 x 0.25 micrograms/d) and calcium (calcium gluconate, 3 x 500 mg/d), the levels of calcium, PTH and enzymes in bone metabolism gradually became normal. A cataract operation had to be performed because of calcification of the lens.

CONCLUSION: The level of PTH should be determined in patients with extensive bone demineralization and hypocalcaemia. If PTH is raised, PHP should be included in the differential diagnosis. Normalization of serum calcium by calcium substitution and vitamin D administration will normalize PTH and improve mineralization of the skeleton. In this way the debilitating effects of osteodystrophia cystica generalisata (OCG) (Engel von Recklinghausen syndrome) can be prevented. Also, the consequences of extraosseous calcification, such as extrapyramidal symptoms of calcification of the brain-stem ganglia can be avoided if treated in time.