Metastatic pulmonary calcification: high-resolution computed tomography findings in 23 cases

Abstract

ObjectiveThe aim of this study was to evaluate the high-resolution computed tomography (HRCT) findings in patients diagnosed with metastatic pulmonary calcification (MPC).Materials and MethodsWe retrospectively reviewed the HRCT findings from 23 cases of MPC [14 men, 9 women; mean age, 54.3 (range, 26-89) years]. The patients were examined between 2000 and 2014 in nine tertiary hospitals in Brazil, Chile, and Canada. Diagnoses were established by histopathologic study in 18 patients and clinical-radiological correlation in 5 patients. Two chest radiologists analyzed the images and reached decisions by consensus.ResultsThe predominant HRCT findings were centrilobular ground-glass nodules (n = 14; 60.9%), consolidation with high attenuation (n = 10; 43.5%), small dense nodules (n = 9; 39.1%), peripheral reticular opacities associated with small calcified nodules (n = 5; 21.7%), and ground-glass opacities without centrilobular ground-glass nodular opacity (n = 5; 21.7%). Vascular calcification within the chest wall was found in four cases and pleural effusion was observed in five cases. The abnormalities were bilateral in 21 cases.ConclusionMPC manifested with three main patterns on HRCT, most commonly centrilobular ground-glass nodules, often containing calcifications, followed by dense consolidation and small solid nodules, most of which were calcified. We also described another pattern of peripheral reticular opacities associated with small calcified nodules. These findings should suggest the diagnosis of MPC in the setting of hypercalcemia.

Metastatic pulmonary calcification: contribution of imaging to noninvasive diagnosis

“…Corroborating the findings of previous studies, Belém et al ( 7 ) demonstrated a clear association between MPC and chronic renal failure, highlighting the strong correlation of the latter condition with cardiovascular events and the greater susceptibility to infections in immunocompromised individuals ( 1 - 4 , 7 , 8 ) . The Belém et al ( 7 ) finding of ground glass opacities—the most common pattern in their sample—broadens the range of differential diagnoses in this group of patients, including congestive conditions and infections ( 9 ) . After ground glass opacities, the most common findings were dense consolidations and calcified micronodules, which also involve multiple differential diagnoses, including other metabolic conditions, pneumoconiosis, and drug (amiodarone) toxicity ( 10 ) .…”

“…The number of cases included allowed the spectrum of known tomography presentations of the disease to be expanded. In some of the patients, the authors identified reticular opacities with calcified micronodules, which have not previously been reported in MPC ( 7 ) .…”

“…In the previous issue of Radiologia Brasileira, Belém et al. ( 7 ) published an interesting retrospective descriptive analysis of the patterns of MPC seen on chest tomography. The sizeable sample of 23 patients, resulting from a multicenter collaboration, made it the largest study of the disease to date.…”

“…Recent studies evaluating complications of lung biopsies at referral centers have reported mortality rates ranging from 1.7% to 3.9%, reaching up to 16% in patients undergoing non-elective biopsy, which underscores the fact that the presence of comorbidities contributes to reducing survival among such patients ( 15 , 16 ) . Therefore, studies of diffuse lung diseases with a focus on noninvasive clinical and imaging-based diagnostic techniques, such as that conducted by Belém et al ( 7 ) , should be encouraged.…”

An unusual cause of pulmonary calcification

“…The hydroxyapatite crystals that form the chief constituent of the calcific deposits in PHPT, avidly absorb 99m Tc-MDP, thus making it a sensitive modality for diagnosis 8. HRCT of the thorax can be normal or show differing patterns of abnormalities like centrilobular ground-glass nodules, calcified nodules, localised or diffuse patchy infiltrates and vascular calcification 9. Calcification is seen in only two-thirds of the patients 10…”