Hypercalcemia as a result of sarcoidosis with normal serum concentrations of vitamin D

Abstract

A 68 yo man with a h/o aortic valve repair in 1995, BPH, and mild renal insufficiency (crea 153 mcmol, nl: 59–104)) developed painful paresthesias in the lower extremities, polyuria, and fatigue. Meds: furosemide, falithromb. No h/o Tbc. On admission, crea 274 mcmol, Ca 3.11 mmol. Physical examination: crackles. Laboratory: serum phos 1.1 mmol (0.84–1.45), intact PTH 0.76 pmol (1.06–6.89), PTHrP <0.5 pmol, nl serum and urinary immunelectrophoresis, ACE 1110 nkat (133–866), IL-2R 2216 U (<710), Neopterin 47 nmol (0–10), 25-OH VitD 34 ng (9–45), 1,25-OH VitD 38 pg (20–46), and 24h urinary Ca 6.86 mmol (<7.5). Prim HPT was excluded. Bone marrow bx was neg for mult myeloma. Abd US: right kidney stones. An x-ray revealed a mass at the lower right hilus. Chest CT demonstrated multiple pleural and intrapulmonary calcifications and lymph node enlargement of approx 3cm size. To further clarify whether a granulomatous disease, malignant lymphoproliferative disorder, or cancer were responsible for this patient's hypercalcemia, we performed a bronchoscopy with lavage and a subcarinal transbronchial bx of pulmonary segment VIII. The CD4/CD8-ratio was elevated with 10.7 (1.1–3.5) and findings suggestive of an early stage of sarcoidosis. TTE showed no evidence for pulmonary hypertension. Pulmonary function tests revealed mild obstruction but no restriction. An empiric trial with prednisolone 40mg/die was initiated while the patient was carefully hydrated. Within 7 days, serum Ca dropped to 2.7 mmol, 1,25-OH VitD to 13.4 ng, and crea to 257 mcmol. For persisting paresthesias, carbamazepine and amitryptiline were given. After 6 weeks of prednisolone therapy, the patient's well being improved. Laboratory: Serum Ca 2.41 mmol, intact PTH 6.26 pmol, 1,25-OH vitD 6 (low), 25-OH VitD 22, ACE 226, IL-2R 1052, and crea 153. On CT, the thoracic mass had shrunken. This case illustrates that hypercalcemia can occur in sarcoidosis with normal 1,25 VitD levels. Contributing factors may include increased uptake of oral Ca or decreased excretion, especially in mild renal insufficiency.