Rare Surgical Lung Biopsy Findings of Metastatic Pulmonary Calcification Associated with Chronic Renal Failure

Abstract

Abstract Introduction/Objective Metastatic pulmonary calcification is a metabolic lung disease characterized by depositions of calcium in lung parenchyma. Depositions of calcium salts are usually caused by hypercalcemia and are associated with end-stage renal disease, primary and secondary hyperparathyroidism, and hemodialysis. It is mostly asymptomatic and clinically silent but can lead to life-threatening respiratory failure. Methods We present a case of a 53-year-old woman, with a failed renal transplant and on hemodialysis, admitted with cough and shortness of breath. Computed tomography showed extensive diffuse bilateral groundglass and nodular opacities. Bronchoscopy was unremarkable. BAL results were negative for infection. The initial differential diagnosis included pneumonitis, interstitial lung disease, and chronic obstructive pulmonary disease. VATS lung wedge resection was performed. Results Microscopically there were numerous interstitial, peribronchial and perivascular calcifications highlighted by Van Kossa stain. Calcifications were associated with a marked interstitial fibrosis confirmed by trichrome stain. There was no evidence of significant acute and chronic inflammation, granulomas, fibroblastic foci and vasculitis. Conclusion Metastatic pulmonary calcification is found in 60–80% of autopsies of patients undergoing dialysis treatment. It is rarely diagnosed during their lifetime, because patients are usually asymptomatic, or the imaging findings are negative. The diagnosis of metastatic pulmonary calcification in our patient prompt further evaluation for repeat kidney transplant and the patient is being considered for parathyroidectomy for her tertiary hyperparathyroidism.