Endocrine Abstracts

Introduction: Hypercalcemia is a relatively common ionic imbalance, mostly due to primary hyperparathyroidism or neoplasia. Hypercalcemia rarely occurs in patients with acute adrenal insufficiency and establishing its etiology can be a challenge. Clinical presentation:We present the case of a 27-year-old patient, admitted in June 2023 with severe fatigue, recurrent diarrhea, vomiting and anorexia, symptoms that have progressively worsened in the last months. He was known to have chronic severe hypocalcemia since childhood, uninvestigated until 2019, when the diagnosis of congenital primary hypoparathyroidism and Fahr syndrome was established. Under treatment with 4.5 grams of calcium and 3 micrograms of alfacalcidol the serum calcium value was maintained at the lower limit of normal. He was also diagnosed with hyperreninemic hypoaldosteronism in 2020 and treated with fludrocortisone, with a normal ACTH-cortisol cycle at that time and subsequently. General examination revealed low blood pressure (90/70 mmHg) and tachycardia, hyperpigmentation of the skin with areas of depigmentation on anterior thorax and forearms (vitiligo). Blood tests showed mild normocytic normochromic anemia (Hgb=12.3 g/dl), moderate hypercalcemia (Ca=13.5 mg/dl) and an altered renal function with a creatinine of 1.58 mg/dl and an eGFR of 61 ml/min/1.73 m2. The hormonal profile revealed a very high ACTH (1706 pg/ml) and a low cortisol (0.11 micrograms/dl) level, with normal thyroid functions and negative thyroid antibodies. We started intravenous hydration plus iv glucocorticoid treatment, with rapid normalization of the renal function and of the serum calcium; alfacalcidol and calcium supplements were withdrawn for 2 days and than resumed. Patient was discharged after 5 days on 7.5 mg prednisone, 0.1 mg fludrocortisone and alfacalcidol and calcium supplements.

Conclusion: This is a case of type 1 autoimmune polyglandular syndrome, which started with hypoparathyroidism, followed by mineralocorticoid deficiency occurring 3 years before the development of cortisol insufficiency.