Endocrine Abstracts

Introduction: Despite the coexistence of secondary hyperparathyroidism with anaemia, hematological manifestations of primary hyperparathyroidism (PHPT) are rare.

Case report: A 67-year-old Caucasian female was admitted to the Department of Internal Medicine due to normocytic anemia and hypercalcemia, diagnosed on occasion of muscle weakness and fatigability for 3 months.

Her medication included: alendronate 70 mg/week, alphacalcidol 1 μg/day, valsartan 160 mg, hydrochlorothiazide 12.5 mg/day, oxcarbazepine 900 mg/day and simvastatin 40 mg/day. Her family history was negative for diseases affecting bone metabolism. No remarkable signs were revealed from clinical examination.

Initial laboratory assessment showed: hematocrit (Ht): 28.6%, hemoglobin (Hb): 9.3 g/dl, white cell count: 6760/μl, platelets: 281 000/μl, urea: 13 mg/dl, creatinine: 1.35 mg/dl, estimated glomerular filtration rate (eGFR): 44 ml/min per 1.73 m², serum total calcium (Ca): 14.3 mg/dl (normal: 8.8–10.6), serum phosphorus (P): 4.9 mg/dl (normal: 2.5–4.5), parathyroid hormone (PTH): 350 pg/ml (normal: 10–53), 25-hydroxyvitamin-D: 7.9 ng/ml (normal: >30 ng/ml), 24 h urinary Ca: 300 mg/24 h (normal: 0–250). Neck ultrasound revealed a hypoechoic lesion 21×5.4 mm suggestive of adenoma of the right lower parathyroid gland, confirmed by Tc99m-sestamibi scan.

Regarding anaemia, comprehensive laboratory, endoscopic and imaging investigation was negative. Bone marrow biopsy and myelogramm showed normal cellularity without fibrosis.

The patient was initially managed with fluid resuscitation, i.v. furosemide and cinacalcet, after alphacalcidol and hydrochlorothiazide discontinuation, which resulted in gradual restoration of renal function and improvement of Ca (10.9 mg/dl). The patient underwent a successful parathyroidectomy, with postoperative PTH: 31.8 pg/ml, Ca: 9.8 mg/dl and P: 3.4 mg/dl.

Surprisingly, Ht and Hb returned to normal postoperatively. In particular, 3 months later, Ht was 34.5% and Hb: 11.5 g/dl, while after 12 months, Ht: 39.8% and Hb: 13.4 g/dl.

Conclusions: Successful parathyroidectomy resulted in resolution of anaemia. The etiology of anaemia is not fully elucidated. Proposed mechanisms are the development of marrow fibrosis and the inhibitory effect of PTH on erythropoiesis.