Excavated pulmonary nodule: steps to diagnosis? Poster No.: C-1044 Congress: ECR 2014 Type: Authors: Keywords: DOI: Educational Exhibit W. Mnari, M. MAATOUK, A. Zrig, B. Hmida, M. GOLLI; Monastir/ TN Metastases, Cavitation, Cancer, Diagnostic procedure, Plain radiographic studies, CT, Thorax, Respiratory system, Lung 10.1594/ecr2014/C-1044 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 14
Learning objectives To report and illustrate the contribution of computed tomography (CT) in characterizing cavitary pulmonary lesions. To sort out the CT signs used in the diagnosis process. To develop an approach to the management of excavated pulmonary nodule involving clinical and imaging data. Background Excavated pulmonary lesion is defined as the presence of neoformed cavity within a solid focal nodule or tissue mass. The etiology of these cavitary lesions is variable, including neoplastic, infectious, inflammatory as well as congenital diseases. Cavitation is due to necrosis of central portion of a lesion and drainage of resultant partially liquefied material via communicating airways. Other mechanisms are mechanical destruction without necrosis and cystic malformation. Findings and procedure details A- Semiotic analysis : The radiographic appearance of cavitary lesions can sometimes be useful to differentiate among a broad spectrum of etiologies but should be combined with clinical and laboratory data to obtain an accurate diagnosis. The most important method used to classify cavitary lesions is to specify cavity wall thickness and the content of the excavated mass. The study include number, the location of the mass, uni or bilateral, size and associated lesions. Wall thickness : - <1 mm è 100% benignant lesion (cyst) - < 4mm è 92% benignant lesion - between 5 and 15 mm è 51 % benignant lesion Page 2 of 14
- > 15 mm è 95% malignant tumor - regular, irregular or nodular wall The content - air - crescent gaz - fluid level - mobile mass B- Infectious disease: This includes bacterial infections such as tuberculosis, fungal infections such as histoplasmosis and coccidiomycosis, and parasitic infections. 1- Tuberculosis Mycobacterium tuberculosis is classically associated with cavitary pulmonary disease. Cavities can vary widely in size and have been reported to have both thick and thin walls. Multiple cavities are often present and frequently occur in areas of consolidation. Location: upper lobe or upper segment of lower lobe. Associated lesions:centrilobular nodules and a tree-in bud appearance in CT scan. Image1and2: Extensive cavitary lung disease due tomycobacterium tuberculosis visualized by computed tomography. Note the typical upper lobe predominance, extensive fibronodular infiltrates and tree in bud sign (circle). 2- Echinococcus Lung cysts usually appear as homogeneous masses by plain chest radiography, but if air penetrates between the cyst walls or into the cyst, a cavitary appearance may result. This appearance has been given a number of names in the radiology literature ("crescent sign," "meniscus sign," and "water lily sign") Spontaneous healing : air filled cyst in lung. Image3: cavitary mass with water lily sign (arrows) 3- Lung abscess Lung abscess is another relatively common bacterial cause of cavitary lung lesions. Page 3 of 14
Image4: Sequelae of severe Staphylococcus aureus pneumonia in a patient with multiple other comorbidities. A residual abscess cavity in the lower right upper lobe. 4- Septic pulmonary emboli Septic pulmonary emboli, although relatively rare, are important considerations in the differential diagnosis of cavitary lung lesions. Septic emboli typically appear as nodules located in the lung periphery. Cavitation is seen in up to 85% of cases using computed tomography. The presence of a "feeding vessel" sign, in which a distinct vessel is seen leading to the center of a pulmonary nodule, suggests the diagnosis of septic embolus. Image5: endocarditis with septic pulmonary emboli, excavated nodule of the right lung. 5- Aspergilloma An aspergilloma, also referred to as a mycetoma or fungus ball, represents growth of aspergillus (usually A. fumigatus) within a preexisting lung cavity. Classically, the most common cause of the cavity was pulmonary tuberculosis. Radiographically, an aspergilloma appears as a rounded opacity within a previously existing cavity; computed tomography can more accurately delineate the mass and surrounding air crescent than plain radiography. Enhancement suggests malignancy. Image6: mobile aspergilloma (ovular mass in the left upper lobe with surrounding air crescent) visualized by computed tomography. C- Noninfectious diseases associated with lung cavities 1- Malignancies : Primary lung cancer: cavitation is more frequently found among cases of squamous cell carcinomas than other histological types. Image7: Large cavitation of righthilar lung cancer. Metastatic tumor: Interestingly, metastatic tumors of squamous cell origin are also more likely to cavitate than tumors of other origins, suggesting a common pathogenesis for cavitations among these tumors (head and neck cancer, bladder cancer ). Image8: Metastatic tumor ofsquamous cell carcinoma of the larynx. Image9: Metastatic tumor ofsquamous cell carcinoma of the bladder. 2- Granulomatosis diseases : Page 4 of 14
Many autoimmune diseases can affect the lung, but cavitation is relatively uncommon in most of these diseases. The exception is Wegener's granulomatosis, an uncommon disorder in which cavitary lung disease is frequently encountered. Pulmonary cavities have been observed by computed tomography in 35 to 50% of patients with Wegener's granulomatosis involving the lung. Image10: Multiple cavitary masses in Wegener's granulomatosis involving the lung. 3- Congenital lung malformations: Type I and II of congenital Cystic Adenomatoid Malformation (CCAM) appear as cystic or fluid-filled masses (Image11). Images for this section: Fig. 1 Page 5 of 14
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Conclusion Excavated pulmonary nodules are commonly encountered in our daily practice. Computed Tomography is very useful in characterizing these lesions and in the differentiation of potential causes. Etiologies are dominated by abscess, tuberculosis,,lung cancer, metastasis and hydatic cyst in endemic areas. Personal information References 1. Cystic and cavitary lung diseases: focal and diffuse. Ryu JH, Swensen SJ. Mayo Clin Proc. 2003 Jun; 78(6):744-52. 2. Cystic and cavitary lesions of the lung: imaging characteristics and differential diagnosis. Abi Khalil S, Aubé. C.J Radiol. 2010 Apr; 91(4):465-73. Page 14 of 14