Endocrine Abstracts

Introduction: Primary hyperparathyroidism associated with multiple myeloma has been rarely reported to coincide, but relapse of previously remitted primary hyperparathyroidism concurrent with a plasma cell proliferative disorder has not been described.

Case report: A 76-year-old female was referred to the endocrine clinic for evaluation of primary hyperparathyroidism discovered incidentally during hospitalization for angina. She had a corrected calcium of 13.9 mg/dl (albumin 2.8 g/dl), phosphate 4.1 mg/dl (2,5-4,5), PTH 369 pg/ml, impaired renal function (eGFR 28,4 ml/min/1.73m²), nephrotic syndrome (5gr protein/24h), hypercalciuria (503 mg/24h), alkaline phosphatase 87 U/L (30-120), uric acid 8.3 mg/dl, Ht 37.6%, Hb 12.7 g/dl, ESR 78 mm/1hr. Cervical ultrasound showed a large cyst at the lower right thyroid pole measuring 3.25 cm, suspicious for a parathyroid cyst. The diagnosis was confirmed by positive PTH (>5000 pg/ml) in the aspirate. Skeletal survey was negative for pathologic fractures and lytic lesions, except for ‘salt and pepper’ skull. Serum free κ chains were 103mg/L (3.3–19.4) and λ chains 62.8 mg/L (5.71–26.3). There was no monoclonal band detected in urine or serum and results of bone marrow aspiration are pending. The patient’s history was remarkable for a hospitalization with hypercalcemic crisis 5 years ago. At that time she had a calcium of 15 mg/dl and a PTH of 433 pg/ml and chronic renal impairment with an eGFR of 50 ml/min/1.73m² (CKD stage 3a). Sestamibi scintigraphy was negative. She was discharged after receiving supportive treatment, including an intravenous bisphosphonate. Past history was negative for kidney stones and osteoporotic fractures. She remained normocalcemic until the present illness, with interim documented calcium levels 9.9–10.1 mg/dl. The patient received an infusion of zolendronate and was started on cinacalcet 30 mg daily. A month later she had an uneventful parathyroidectomy. Conclusive diagnosis and treatment of the hematologic disorder is pending.

Conclusion: The classic CRAB criteria cannot be applied for the diagnosis of multiple myeloma and related disorders in the presence of primary hyperparathyroidism, because of common features shared between the two conditions, worsening each of them. Parathyroidectomy in these cases is desirable as it favorably affects treatment, follow up and perhaps prognosis of the hematologic disorder.