Endocrine Abstracts

Introduction: Hungry bone syndrome (HBS) is a rare condition that can appear after surgery for hyperparathyroidism, characterized by hypocalcemia, hypophosphatemia, low calciuria, especially in patients with severe primary hyperparathyroidism, bone lesions and elevated alkaline phosphatase. We present a case of severe persistent hypocalcemia after resection of a giant parathyroid adenoma in a patient with concurrent osteoblastic bone metastasis from prostate cancer.

Case report: A 60 year-old man, who recently underwent surgery for prostate adenocarcinoma, was admitted with newly diagnosed parathyroid adenoma identified during his oncological follow-up. He described generalized weakness, intense back-pain and constipation. Personal history includes gastric resection with gastroenteroanastomosis. Blood tests showed hypercalcemia of 13.6 – 14 mg/dl, normophosphatemia 2.6mg/dl and high alkaline phosphatase of 555U/l, high parathyroid hormone (PTH) 605 pg/ml and bone turnover markers: C-telopeptide 3.32ng/ml, P1NP 1168 ng/ml, osteocalcin 304 ng/ml. Medical treatment with intravenous Zoledronic acid, rehydration, pain relievers was initiated. Full-body CT scan revealed a large right-inferior parathyroid adenoma and multiple osteosclerotic lesions. Parathyroidectomy was performed and histopathological examination confirmed an 9 g and 37/18/19mm parathyroid adenoma. The postoperative period was characterized by severe hypocalcemia (range between 6.6-8.24 mg/dl), hypophosphatemia (range between 1.9-2.6 mg/dl), normal PTH, and also an inflammatory syndrome with acute pain due to chondrocalcinosis crisis of 1st left metatarsophalangeal joint and left knee joint. The patient was discharged with improved clinical and biochemical features on high doses of citrate-calcium and calcitriol.

Conclusion: This case reflects the rare occurence of many mechanisms concurring to hypocalcemia: hungry bone syndrome, osteoblastic metastasis and gastric resection.