Fulminant pulmonary calciphylaxis and metastatic calcification causing acute respiratory failure in a uremic patient.

Calciphylaxis is a rare and life-threatening disorder characterized by small-vessel mural calcification with intimal proliferation, fibrosis, and thrombosis, resulting in tissue ischemic necrosis. Although it has been viewed as a systemic disease involving mainly the dermis, subcutaneous fat, or muscle, calciphylaxis of other organs rarely is reported. We describe the case of a 25-year-old uremic woman who rapidly developed massive pulmonary calcification that led to acute respiratory failure after the initiation of hemodialysis therapy. Chest radiography and high-resolution computed tomography showed typical pulmonary calcification. Pulmonary calciphylaxis and metastatic calcification were confirmed further by lung tissue biopsy. No skin or muscle calciphylaxis was discovered. Despite multiple factors precipitating pulmonary calciphylaxis in this patient, we speculate that hemodialysis was the main culprit in accelerating the development of fulminant pulmonary calciphylaxis and metastatic calcification. Alteration in the local environment from an acid to an alkaline condition and a relatively high dialysate calcium level in the presence of systemic hyperphosphatemia are believed to have facilitated the deposition of calcification. This case highlights the importance of "visceral calciphylaxis" and early identification of its causes.