Evidence of unilateral metastatic pulmonary calcification with a prolonged Fever and arthralgia caused by acute lymphoblastic leukemia in a chronic dialysis patient

Pathological and Radiological Correlation in Prolonged Myeloperoxidase Anti-neutrophil Cytoplasmic Antibody-related Diffuse Alveolar Hemosiderosis

A 60-year-old woman with a 20-year history of myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis visited our hospital due to productive cough and a low-grade fever for several weeks. Thoracic computed tomography demonstrated scattered tiny nodules, patchy consolidation, ground glass opacities, and thickening interlobular septa. On video-assisted thoracic surgery, those abnormalities were found to correspond to the accumulation of hemosiderin-laden alveolar macrophages (AMs) in the alveolar spaces and alveolar septa due to MPO-ANCA vasculitis. The radiological findings persisted for a further two years, indicating the possibility of persistent vasculitis in the lung or evidence of incomplete clearance of hemosiderin-laden AMs.

Metastatic pulmonary calcification: Experience from a single center in Singapore

Metastatic pulmonary calcification (MPC) was seen in 79% of patients with end-stage renal disease (ESRD) during autopsy. However, it is not commonly diagnosed in vivo. Its pathogenesis is not fully understood. We report a retrospective series of 5 cases of MPC from a single center in Singapore. MPC were diagnosed using radiological or histological features. Mean onset of MPC from diagnosis of ESRD was 22.6 ± 3.1 years. One patient remains asymptomatic. Four patients died, one was related to MPC. All patients had calcifications at the lung apices on radiological studies. Three patients with MPC were diagnosed based on radiological features while 2 had histological features. Four patients underwent parathyroidectomy without radiological changes before parathyroidectomy. Median intact parathyroid hormone of this series was 5.6 pmol/L (IQR 1.3-139.4), alkaline phosphatase 74 U/L (IQR 62-461), calcium 2.10 mmol/L (IQR 1.85-2.40), and phosphate 1.30 mmol/L (IQR 0.87-1.63). The observed low iPTH suggests that MPC might occur in low iPTH. Our case series showed MPC might occur in low iPTH after parathyroidectomy, in contrast to existing literature that suggests MPC is diagnosed in patients with elevated iPTH. Parathyroidectomy does not prevent MPC.