Pleural Calcification



Pleural Calcification


Jeffrey P. Kanne, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Asbestos-related Pleural Disease


  • Empyema


  • Exudative Pleural Effusion


Less Common



  • Pleural Metastasis


  • Hemothorax


  • Pleurodesis


  • Radiation-induced Lung Disease


Rare but Important



  • Fibrous Tumor of Pleura


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Pleural plaques are usually the result of asbestos exposure


  • Pleural thickening from any cause can calcify



    • Infection, hemorrhage, and asbestos account for most pleural calcification


    • Exuberant pleural calcification most commonly from tuberculosis


  • Associated lung or chest wall findings may suggest underlying cause


  • CT more sensitive than radiography


Helpful Clues for Common Diagnoses



  • Asbestos-related Pleural Disease



    • Usually develops 20-30 years after exposure


    • Usually bilateral


    • Calcification occurs in ˜ 15%



      • CT more sensitive than radiography for calcification


    • Characteristic locations



      • Posterolateral chest wall between 6th and 9th ribs


      • Dome of diaphragm


      • Mediastinal pleura, particularly over diaphragm


    • Diaphragmatic calcification highly suggestive of asbestos exposure


    • Unusual in apices or costophrenic sulci


    • Associated lung findings



      • Subpleural curvilinear opacities


      • Parenchymal bands


      • Rounded atelectasis adjacent to visceral pleural thickening


      • Interstitial fibrosis (asbestosis)


  • Empyema



    • Usually unilateral


    • Tuberculosis most common cause worldwide



      • Pulmonary findings of TB present in about 85% with tuberculous empyema


      • Typically develops 3-6 months following primary infection


      • Caused by rupture of subpleural nidus of pulmonary infection into pleural space


    • Thickening of parietal and visceral pleura



      • May become sheet-like


      • Often most extensive posterolaterally


      • Residual effusion in ˜ 15%


    • May lead to fibrothorax



      • Extensive calcification


      • Volume loss in affected lung (restrictive lung disease)


      • Compressive and rounded atelectasis


  • Exudative Pleural Effusion



    • Usually unilateral


    • Calcification less common than with empyema


    • Associated pleural thickening


    • Adjacent pneumonia or other pulmonary inflammation may be present initially


    • Progression to empyema in 10% of patients hospitalized with pneumonia and parapneumonic effusion



      • Streptococcus and Staphylococcus species most common


      • Nosocomial infection with gram-negative anaerobes and methicillin-resistant Staphylococcus aureus (MRSA)


      • Up to 1/3 caused by anaerobic organisms


Helpful Clues for Less Common Diagnoses



  • Pleural Metastasis



    • ˜ 90% of all pleural neoplasms


    • Usually multiple


    • Calcified pleural metastases



      • Chondrosarcoma


      • Osteosarcoma


      • Sarcomatous mesothelioma


      • Adenocarcinomas (especially mucinous subtypes), including lung, breast, gastric, and ovarian


    • Associated pleural effusion in most


    • May have lung or thoracic lymph node metastases



  • Hemothorax



    • Usually unilateral


    • Blunt or penetrating trauma


    • Iatrogenic


    • Parietal and visceral pleura calcification



      • Late finding


      • Can become sheet-like


      • Often most extensive posterolaterally


      • Varying amount of residual pleural fluid


    • Adjacent healed rib fractures suggestive


  • Pleurodesis



    • High-attenuation deposits mimic pleural calcification



      • Usually adjacent to dependent lung


      • May be lentiform


    • Variable degrees of pleural thickening and nodularity



      • Remain stable over time


      • May enhance with large amount of granulation tissue


    • Residual loculations of fluid common


  • Radiation-induced Lung Disease



    • Unusual complication of radiation therapy for breast cancer, lung cancer, or lymphoma


    • Associated with pleural thickening


    • Small residual pleural effusion may be present


    • Radiation-induced lung fibrosis often present in radiation field


Helpful Clues for Rare Diagnoses



  • Fibrous Tumor of Pleura



    • Single well-defined soft tissue mass abutting pleura



      • 65-80% arise from visceral pleura


      • 20-35% arise from parietal pleural


      • Fissural origin not uncommon


      • ˜ 50% arise from vascular pedicle (rarely evident on CT)


    • Variable size



      • Range from 1-36 cm, mean is 6 cm


    • Intermediate to high attenuation on unenhanced CT



      • Attributed to abundant capillary network and high density of collagen


    • Most exhibit intense contrast enhancement on CT and MR



      • Sparing in areas of necrosis or myxoid degeneration


    • Calcification in 7-25%



      • More common in larger tumors


      • Usually associated with necrosis


    • Pleural effusion in 25-37%


    • Paraneoplastic syndromes



      • Hypoglycemia in up to 7%


      • Clubbing of fingers in 4%


      • Resolve after tumor resection


    • ˜ 12% malignant



      • Vascular pedicle less common with malignant tumors


      • Usually heterogeneous on unenhanced and contrast-enhanced CT and MR


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Aug 8, 2016 | Posted by in CARDIOLOGY | Comments Off on Pleural Calcification

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