原発性副甲状腺機能亢進症患者における副甲状腺摘出術後の石灰化症：まれな合併症

Calciphylaxis, a rare and life-threatening condition involving calcification of small to medium-sized arterioles in subcutaneous tissue, leads to ischemia and necrosis. While typically seen in chronic kidney disease (CKD), a small proportion of cases can present without CKD, referred to as nonuremic calciphylaxis (NUC). NUC associated with primary hyperparathyroidism is rare with limited evidence-based management. A 41-year-old woman with no prior medical history presented with cardiac arrest due to severe hypercalcemia of 17.87 mg/dL (4.46 mmol/L) (normal reference range, 8.6-10.3 mg/dL; 2.2-2.6 mmol/L) and markedly elevated parathyroid hormone (PTH) levels. She required intensive care and extracorporeal membrane oxygenation (ECMO). Following stabilization, she underwent emergency parathyroidectomy for a parathyroid adenoma. During her prolonged recovery over 100 days, she developed painful necrotic skin lesions. Histopathology confirmed calciphylaxis. Management was conservative, involving wound care and analgesia, without surgical debridement. Her skin lesions resolved, and she has remained free of recurrence with stable calcium and PTH levels for more than 10 years. NUC following parathyroidectomy for primary hyperparathyroidism is rare. Multifactorial causes could contribute to the pathogenesis of calciphylaxis in our case, involving acute kidney injury, ECMO, and prolonged immobility. Early recognition and multidisciplinary management are crucial given the high mortality rate in calciphylaxis.