Endocrine Abstracts

Introduction: Hypercalcemia is a frequent hydroelectrolytic disorder, and primary hyperparathyroidism is the most common cause in oupatients. It is important to make an early diagnosis and adequate treatment in order to avoid possible complications such as nephrolithiasis, osteoporosis or the deterioration of glomerular filtration rate.

Clinical case: A 63-year-old female patient referred for hypercalcemia. Past medical history included stage IV chronic renal failure (with more marked deterioration of glomerular filtration in the last year) and recurrent bronchitis. She had polydipsia, polyuria, asthenia and 10 kg weight loss in the last year. Physical exam was normal except for mobile, soft bilateral supraclavicular, axillary and inguinal lymphadenopathies. Laboratory findings were as follow: Creatinine: 2.32 mg/dl (0.51–0.95), Corrected calcium:14.19 mg/dl (8.1–10.5), Phosphorus: 3.5 mg/dl (2.5–4.5), Angiotensin converting enzyme: 242 U/L (8.0–52), Parathormone related protein: <1.10 pmol /L (0.00–1.50); 1,25 hydroxyvitamin D: 99 pg/mL (16-56), intact PTH: 7.8 pg/mL (10.0–65.0), 25 hydroxyvitamin D: 18.3 ng/mL (Deficit: <20), Calcium/creatinine: 0.652, B2microglobulin: 11.06 mcg/ml (0.80–2.34), Leukocytes: 7750 10E3/μl (4.50–11.00), Erythrocyte sedimentation rate: 30 mm (1–20). No Monoclonal Component was evidenced. Bacilloscopy and mycobacterial culture: Negative, QuantiFERON-TB: Negative. Thorax radiography: Bilateral hilar adenopathies, without clear interstitial pattern. High resolution tomography: Supraclavicular, mediastinal, hilar, axillary, retrocrural, abdominopelvic, iliac and inguinal adenopathies; bilateral subpleural nodular lesions, focal splenic lesion of 0.8×0.70 mm. Biopsy of supraclavicular nodes showed non-necrotizing granulomas compatible with Sarcoidosis. Improvement of calcemia and renal function was obtained with intravenous hydration. After confirming the diagnosis of sarcoidosis, treatment with corticosteroids and hydroxychloroquine was initiated (current: corrected calcium 10.78 mg/dl; Cr 1.47 mg/dl)

Conclusion: Sarcoidosis is a rare cause of hypercalcemia, wich occurs as a result of the overexpression of the enzyme 1α-hydroxylase in the macrophages of granulomas (with the consequent increase of 1, 25-OH-vitamin D). It is essential to considered it in the differential diagnosis of non-PTH-dependent hypercalcemia.