K Swaraj, R Mansberg, L Emmet, M Magee, H Van der Wall
dystrophic calcification, idiopathic hypercalcaemia
K Swaraj, R Mansberg, L Emmet, M Magee, H Van der Wall. Severe Idiopathic Hypercalcemia In A Young Female Demonstrated On Skeletal Scintigraphy. The Internet Journal of Nuclear Medicine. 2006 Volume 3 Number 2.
A 30 year old female developed nodules on the extensor services of the forearms, knees and back and was noted to have hypercalcemia. Skeletal scintigraphy demonstrated increased uptake throughout the lung fields diffusely and in multiple joints. Multiple investigations were unsuccessful in revealing a cause of the hypercalcemia but confirmed widespread organ calcification. This case is unusual due to the young age of the patient, severity of manifestations on imaging techniques and the lack of an underlying aetiology.
Investigations revealed hypercalcemia 3.32 mmol/L corrected ( NR 2.1-2.6 mmol/L ) and renal failure Cr 215 µmol (NR 50-90 µmol/L). Her parathyroid hormone, ACE and urinary Calcium levels were normal. She was referred for a bone scan to exclude metastatic bone disease as a cause of her hypercalcemia. Whole body scintigraphy performed 3 hours following administration of 25 mCi (1000 MBq) 99m MDP revealed diffuse intense tracer uptake by the lungs and throughout the joints. Linearly increased uptake was noted in the midline of the skull.
Lung function tests and bronchoscopy revealed calcification of airways.
Renal biopsy showed nephrocalcinosis with deposition of calcium in tubules and glomeruli with chronic inflammatory changes.
A skeletal survey and bone marrow biopsy were normal.
The patient was diagnosed with idiopathic hypercalcemia in the absence of an underlying pathology and commenced on high dose corticosteroid therapy with good initial response.
Hypercalcemia can be a manifestation of a serious illness such as malignancy (1) or can be detected incidentally by laboratory testing in a patient with no obvious illness.
Whenever hypercalcemia is confirmed, a definitive diagnosis must be established. Although hyperparathyroidism, a frequent cause of asymptomatic hypercalcemia, is a chronic disorder in which manifestations, if any, may be expressed only after months or years, hypercalcemia (2 ) can also be the earliest manifestation of malignancy, the second most common cause of hypercalcemia in the adult. The causes of hypercalcemia are numerous, though hyperparathyroidism and cancer (3, 4) account for 90% of cases.
Hypercalcemia in an adult who is asymptomatic is usually due to primary hyperparathyroidism. In malignancy-associated hypercalcemia the disease is usually not occult; rather, symptoms of malignancy bring the patient to the physician, and hypercalcemia is discovered during the evaluation. In such patients the interval between detection of hypercalcemia and death is often <6 months. Accordingly, if an asymptomatic individual has had hypercalcemia or some manifestation of hypercalcemia, such as kidney stones, for >1 or 2 years, it is unlikely that malignancy is the cause. Nevertheless, differentiating primary hyperparathyroidism from
Dr R Mansberg Department of Nuclear Medicine Concord Hospital Concord NSW 213 Australia Tel +61297676339 Fax +61297677451 Email: firstname.lastname@example.org