METASTATIC PULMONARY CALCIFICATION MIMICKING AIR-SPACE DISEASE - TECHNETIUM-99M-MDP SPECT IMAGING

Metastatic pulmonary calcification (MPC), a complication of chronic re nal failure, is uncommonly diagnosed antemortem, yet may be a signific ant etiology of pulmonary dysfunction in patients with renal failure. The degree of respiratory distress often does not correlate with the d egree of macroscopic calcification. Patients with extensive calcificat ion may be asymptomatic, while others with subtle calcification or nor mal chest radiographs may have severe respiratory compromise. Addition ally, the findings on chest radiographs may be confused with air-space disease, including pulmonary edema and pneumonia. Radionuclide imagin g may detect MPC in the setting of normal chest radiographs, and confi rm the diagnosis when there are radiographic findings of air-space dis ease without macroscopic calcification. We present a patient with bila teral upper lobe disease suspected to represent edema or pneumonia, pr oven to represent MPC on Tc-99m MDP scintigraphy with single photon em ission computed tomography (SPECT), CT, and later at transbronchial bi opsy.