Lung and gastric uptake of 99mTc-MDP in bone scintigraphy in a patient with hypercalcemia induced by alfacalcidol administration

Bone scintigraphy of a patient with hypercalcemia and renal failure resulting from vitamin D administration showed massive technetium-99m methylene diphosphonate (Tc-99m-MDP) uptake in the lung and stomach. Our patient is the second reported case of lung and stomach uptake of Tc-99m-MDP induced by vitamin D. Alfacalcidol (la-hydroxy vitamin D-3) at a dosage of 0.5 mu g per day had been administered for 1 year, but no calcium-enriched foodstuffs were ingested. We examined 1,25 (OH)2 vitamin D levels and performed an alfacalcidol loading test after the laboratory data improved. The 1,25 (OH)2 vitamin D levels before and at 3 hours and 6 hours after the first administration and 7 days after continuous administration of 0.5 mu g alfacalcidol per day were 60 pg/mL (normal range, 20-60 pg/mL), 61, 67, and 66 pg/mL, respectively. This suggests that the synthesis of active vitamin D might be enhanced in this patient by an unknown cause.