An approach to the differential diagnosis of non-neoplastic pulmonary masses.

Transcription

1 An approach to the differential diagnosis of non-neoplastic pulmonary masses. Poster No.: C-1587 Congress: ECR 2013 Type: Educational Exhibit Authors: P. Diana, S. L. Betancourt; Houston, TX/US Keywords: Infection, Congenital, Biopsy, Plain radiographic studies, PET-CT, CT, Thorax, Respiratory system, Lung, Inflammation DOI: /ecr2013/C-1587 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. Page 1 of 43

2 Learning objectives To describe, according to etiology categories, the differential diagnosis of solitary or multiple pulmonary masses that resemble malignancy. To review the clinical presentation and imaging appearance of various disease entities presenting as pulmonary mass or masses. Background Statistically pulmonary masses larger than 3 cm are more likely to be malignant, but a number of other benign diseases may present similarly. The radiographic assessment of patients with single or pulmonary masses may pose a clinical problem. In many cases, the radiologist may play a major role by avoiding additional unnecessary imaging work-up, costly interventional procedures and patient anxiety, when a systematic approach is followed. It is widely recognized that certain imaging characteristics in a mass, are highly suspicious for malignancy. However often times, when equivocal for a neoplastic process, a good clinical history plays a fundamental role (as in almost any other Imaging interrogation) in the formulation and narrowing of the differential diagnosis. This invaluable information is emphasized in our review. The second major point in our approach to non-neoplastic lung masses is to review certain imaging features that are inherent to a particular benign entity, in some cases, unequivocally diagnostic of the condition. For didactic purposes, we classified the origin of benign pulmonary masses into 4 groups: congenital, infectious, inflammatory and miscellaneous (fig 1). Page 2 of 43

3 Fig. 1 An elaborated description of each group and imaging examples are included in this presentation. Imaging findings OR Procedure details #CONGENITAL LESIONS BRONCHIAL ATRESIA Proximal obliteration of a segmental bronchus Distal airways aerated via collateral pathways Upper lobes most common Most patients are asymptomatic Chest Radiograph Central nodule or mass +/- air Page 3 of 43

4 Characteristically surrounded by hyperlucent lung Fig. 2: Bronchial atresia in an asymptomatic 34 year old man. Chest radiograph shows a right upper lobe mass. There is adjacent hyperlucency as compared to the left upper lobe. Chest CT Central masslike opacity (mucocele) Surrounding hyperlucent lung due to air-trapping and hypo-vascularity of the Page 4 of 43

5 adjacent parenchyma. Fig. 3: Bronchial atresia in an asymptomatic 34 year old man. CT (lung window) shows mucous impaction in a dilated right upper lobe segmental bronchus and surrounding hyperlucent lung. INTRAPULMONARY SEQUESTRATION (figs 4-5) Pulmonary tissue without communication with central airway Systemic arterial supply and pulmonary venous drainage Associated with chronic infection in adults Lower lobes: Left sided 60% Chest Radiograph Mass like consolidation Page 5 of 43

6 Paravertebral portion of the lower lobes 1/3 contain air or air-fluid level Fig. 4: Intrapulmonary sequestration in a 50 year old male with history of chronic lung infection. Chest radiograph shows a poorly defined opacity in the right lower lobe (arrow). Chest CT Complex lesion: solid, fluid and/or cystic component 80% systemic arterial supply from aorta Page 6 of 43

7 Fig. 5: Intrapulmonary sequestration in a 50 year old male with history of chronic lung infection. Contrast-enhanced CT coronal reformat shows a heterogeneous mass in the right lower lobe. Note the systemic arterial supply (short arrow) arising from the distal thoracic aorta. ARTERIOVENOUS MALFORMATION AVMs result from abnormal communication between the pulmonary arteries and veins AVMs are more common in women than men Detected in the 3rd or 4th decade of life 33% are multiple Often asymptomatic or may present with hemoptysis Chest Radiograph: Peripheral well defined nodule or mass, that increases in size with Valsalva maneuver Page 7 of 43

8 May show large feeding and/or draining vessels extending towards the hilum Fig. 6: Pulmonary arteriovenous malformation. Chest radiograph,frontal view) shows a well-circumscribed mass in the lingula. Chest CT Subpleural nodule or mass with converging enlarged feeding and draining vessels Follows the arterio-venous pattern of enhancement Page 8 of 43

9 Fig. 7: Pulmonary arteriovenous malformation. CT (Lung window) demonstrates the vascular nature of the lesion with enlarged feeding and draining vessels BRONCHOGENIC CYST Lined by respiratory epithelium Contains mucous material 15% are intrapulmonary Medial and lower lungs Usually incidental finding, but may present with chest pain, dyspnea and fever if infected Page 9 of 43

10 Chest Radiograph Sharply marginated nodule or mass Air-fluid level if cyst is infected or communicating with the airways Chest CT Well-circumscribed, homogeneous mass near a major bronchus Variable CT attenuation: About half show water and half,soft tissue attenuation May have wall calcification Fig. 8: Bronchogenic cyst in an asymptomatic 25 year old man. Chest CT (mediastinal window) displays a well marginated homogeneous bi-lobed fluid attenuation central mass in the right lower lobe INFECTIOUS LESIONS Page 10 of 43

11 GRANULOMA Multiple causes: tuberculosis, non-tuberculous mycobacteria, and fungal infection In the US most commonly related to histoplasmosis Typically asymptomatic. Less likely chronic respiratory symptoms, low grade fever and wasting which may mislead towards malignancy Chest Radiograph A granuloma is less commonly greater than 3 cm. When this size, it is a well defined mass; which may be non, partially or less likely completelely calcified. The typical target lesion (central calcification) is diagnostic of histoplasmoma Page 11 of 43

12 Fig. 9: 45 year old man with incidental mass found con chest radiograph. A well defined 3 cm lesion is seen in the left lower lobe. No evidence of calcification is noted. Fig. 10: Chest CT in the same patient, demonstrates a non-specific homogeneous soft tissue mass of well-defined contours. Biopsy proven histoplasmoma. Chest CT Sharply marginated soft tissue mass. Calcification when present is readily classified as benign when central or lamellar. In abscense of calcification or with less common eccentric or stippled, calcification,biopsy may be necessary. ROUND PNEUMONIA Is more frequently a pediatric presentation More commonly bacterial, or fungal; occasionally vira Page 12 of 43

13 The typical course is that of acute or sub-acute respiratory symptoms of communityacquired pneumonia which commonly prompt the correct diagnosis Chest Radiograph Round consolidation (s) with or without air bronchogram. Rapid growth on short term follow-up studies is a clue to diagnosis in the proper clinical setting Fig. 11: Round pneumonia. A. 68 year old smoker with fever and cough. Chest radiograph shows a large mass-like opacity with subtle adjacent ground glass opacities and interstitial prominence. Chest CT One or several foci of mass-like consolidation. One of the common features less associated with malignancy is the presence of surrounding "tree in bud" opacities and / or adjacent nodular or patchy opacities Page 13 of 43

14 The halo sign may be present, particularly in cases of opportunistic angioinvasive aspergillosis, but is nonspecific Fig. 12: Round pneumonia. A. 68 year old smoker with fever and cough. Chest CT (lung window) confirms a mass-like consolidation in the right lower lobe, with air bronchogram. PULMONARY ABSCESS May result from bacterial, mycobacterial, fungal, parasitic and rarely from viral infections Anaerobic etiology is associated with periodontal disease Subacute process typically associated with low grade fever, cough and sputum production for weeks Chest Radiograph Round or oval,irregular mass, displaying acute angles with the pleura. The outer aspect may be ill-defined due to surrounding inflammation and lung consolidation Air-fluid level if communication with a bronchus and partial drainage can occur Page 14 of 43

15 Chest CT Mass with densely enhancing wall of variable thickness. Characteristically the the content is low in attenuation, with or without air-fluid level Bronchi may be seen entering the abscess Fig. 13: Lung abscess in a 59 year old male with history of alcoholism. Chest CT (Mediastinal window). Cavitary mass with thick enhancing wall in the right lower lobe. An air-fluid level is also present (arrow). Page 15 of 43

16 Fig. 14: Lung abscess in a 59 year old male with history of alcoholism. Chest CT (Lung window). The right lower lobe mass shows a halo of ground-glass opacity often seen with these lesions. The gas content is also noted. MYCETOMA Consists of a ball of coalescent mycelial hyphae, which colonize preexisting chronic cavities May be first discovered on a chest radiograph as an incidental finding Hemoptysis is seen in less than half of the patients Chest Radiograph Round soft tissue mass usually in the upper lobes. Air between the fungus ball and the wall ("crescent sign") may be seen Chest CT Well defined soft tissue or "sponge-like" mass with or without the " air crescent sign". The mobility of the fungus ball may be demonstrated by change in patient positioning Page 16 of 43

17 Fig. 15: Mycetoma in a 76 year old man with chronic cough. CT (lung window) show a large cavity containing a soft tissue mass, associated with focal pleural thickening. Note the lucency surrounding it, the "crescent sign" NOCARDIOSIS Uncommon, Aerobic gram-positive bacilli More common in males, particularly Immunocompromised patients Symptoms: low-grade fever, cough, weight loss with exacerbations and remissions over periods of days to weeks Chest Radiograph Homogeneous nonsegmental consolidation and less commonly nodule (s) or mass (es).cavitation is seen in 35% of cases. Pleural effusion is common Chest CT Nodule (s) or mass (es) with irregular borders, mimicking malignancy is a common presentation. Abscess formation and cavitation is frequently seen Pleural effusion or pleural thickening may be seen Page 17 of 43

18 Fig. 16: Biopsy proven Nocardiosis in a 49 year old immunocompetent man. Chest CT (lung window) shows a spiculated mass in the right upper lobe with irregular contours and focal pleural thickening. Page 18 of 43

19 Fig. 17: Biopsy proven Nocardiosis in a 49 year old immunocompetent man. Integrated PET/CT shows intense FDG uptake in a irregular cavitated and spiculated mass. Differentiation from lung cancer from the imaging stand-point is impossible. The clinical history is however compelling to move opportunistic infection to the first place in the list of differential diagnosis. ACTINOMYCOSIS Anaerobic filamentous bacteria Poor oral hygiene, alcoholism Chronic granulomatous infection with suppuration, sulfur granules, abscess formation and sinus tracts Symptoms: Low-grade fever and cough Pleuritic chest pain with pleural and chest wall involvement Chest Radiograph Page 19 of 43

20 Unilateral, peripheral patchy consolidation or mass-like consolidation. Extension to the pleura with thickening, effusion and empyema is common Chest CT Mass like consolidation with areas of low attenuation due to abscess formation and adjacent pleural thickening/ empyema formation Extension to the mediastinum, pericardium and chest wall is common Fig. 18: 70 year old female with severe emphysema and low grade fever. Chest CT (lung window) shows an irregular, spiculated mass in the right apex. Biopsy of this lesion revealed anaerobic filamentous bacteria (Actinomyces Israelii ) A-B. Page 20 of 43

21 Fig. 19: 70 year old female with severe emphysema and low grade fever. Integrated PET/CT shows mild FDG uptake in this biopsy proven Actinomycosis lesion. INFLAMMATORY CONDITIONS SARCOIDOSIS This systemic disorder may occur at any age but is more common in women between years old. The incidence is greater in African Americans.30-50% of patients are asymptomatic The most common pulmonary complaints are dyspnea, cough, and chest pain Chest Radiograph In patients with stage II there may be lung involvement associated with mediastinal and hilar adenopathy. Patients with stage III and IV will show parenchymal disease. Although small perilymphatic nodularity is more common, large mass-like opacities can be seen. Chest CT Page 21 of 43

22 Large ill-defined nodules or masses,may contain air bronchogram. This is the so called "alveolar sarcoidosis", which is a misnomer since the disease is interstitial in nature. The mass like appearance corresponds to confluent interstitial granulomas. Adjacent peribronchial satellite nodules may be a clue to the diagnosis and differentiation from malignancy. Most of the cases accompanied by mediastinal and hilar adenopathy (see our example) Cavitation can be present Fig. 20: Biopsy proven sarcoidosis in a a 48 year old woman with chronic dry cough. Severalill-defined mass-like lesions were present in this patient, from nodules such as this ill-defined right upper lobe lesion (arrow), to masses(see next image). Page 22 of 43

23 Fig. 21: Biopsy proven sarcoidosis in a a 48 year old woman with chronic dry cough. Severalill-defined mass-like lesions were present in this patient, the largest of which is displayed in this CT axial lung window image. LIPOID PNEUMONIA Chronic aspiration of mineral oils or other lipids producing a foreign body inflammatory reaction in the lung Associated with swallowing disorders and more common in elderly patients The clinical history is crucial! Need to elicit relevant clinical information from patients Diagnosis can be suggested radiologically, but often discovered on pathologic examination Chest Radiograph Page 23 of 43

24 Poorly defined consolidation or mass, sometimes mimicking malignancy. the middle lobe and lower lobes are more commonly affected Fig. 22: 61 year old man with history of chronic oil laxative use. Chest radiograph shows a poorly defined opacity in the right lower lobe. Chest CT Dependent consolidation that may be low and fat in attenuation which is clue for diagnosis. A "crazy-paving" pattern of septal thickening and superimposed ground glass Page 24 of 43

25 attenuation has also been described. Biopsy is usually necessary in the absence of fat attenuation Fig. 23: 61 year old man with history of chronic oil laxative use. Close up -CT axial image in mediastinal demonstrates an irregular mass with central fat attenuation, consistent with lipoid pneumonia. AMYLOIDOMA Page 25 of 43

26 Abnormal protein deposited in extracellular tissues The three patterns are tracheobronchial, parenchymal and diffuse interstitial disease Parenchyma involvement: nodular or mass-like lesions Most are asymptomatic Lower lobes and peripheral location Chest Radiograph Single or multiple peripheral nodules or masses which have been described as large as 15 cm. 20% calcify Chest CT Mass or masses with well-defined irregular borders. Stippled or dense calcification or cavitation may be seen Usually require biopsy for confimation unless proven long standing stability Page 26 of 43

27 Fig. 24: Biopsy proven secondary amyloidois in a 49 year old female patient with multiple myeloma Chest CT ( lung window) show a lobulated mass with irregular contours Page 27 of 43

28 Fig. 25: Biopsy proven secondary amyloidois in a 49 year old female patient with multiple myeloma Chest CT ( Mediastinal window) show a mass with irregular contours containing punctate densities in keeping with stippled calcifications WEGENERS GRANULOMATOSIS Necrotizing granulomatous inflammation Typically affects adults between 40 and 60 years of age Serum C-ANCA are present in 90-95% Symptoms include epistaxis, sinusitis, cough and hemoptysis Diagnosis is made by a combination of clinical, radiological findings and the presence of c-anca Chest Radiograph Multiple pulmonary nodules and masses are the presentation in up to 90% of patients. Airspace consolidation is the second most common finding. Occasionally solitary mass Chest CT Page 28 of 43

29 Multiple nodules or masses commonly with air-bronchogram.. 50% are cavitary Other presentations include: Patchy, confluent or peribrochial consolidation, groundglass opacities in 20% and bronchial wall thickening in 50-60% Fig. 26: Wegener granulomatosis in a 38 year old male. Chest CT (lung window) shows a soft tissue mass in the left lower lobe. There are also contralateral small nodules (arrows). CRYPTOGENIC ORGANIZING PNEUMONIA Histologic reaction pattern that may be idiopathic, but can also be seen in association with infections, connective tissue disease, drug reaction, radiation therapy, inhalational injury and aspiration Clinical manifestations include cough, dyspnea and low-grade fever In most patients the diagnosis is made based on clinical findings and transbronchial biopsy Page 29 of 43

30 Chest Radiograph Subacute or chronic asymmetric uni or bilateral multifocal consolidation, but also nodules or masses are described. Chest CT When the disease is present in the form of masses, these may be single or multiple, and irregular in shape, more commonly peripheral. A "reversed halo' sign may be seen in 20% of the patients Fig. 27: 52 year old male with chronic cough for 3 months. Biopsy proven organizing pneumonia. Chest CT (lung window). There is a well-defined mass in the right middle lobe D. Page 30 of 43

31 Fig. 28: 52 year old male with cough for 3 months. Biopsy proven organizing pneumonia.integrated PET/ CT demonstrates significant FDG-uptake resembling malignancy INFLAMMATORY PSEUDOTUMOR Fibro-inflammatory lesion Rare, affecting young adults and children Usually benign but may be invasive Consists of a mixture of inflammatory cells, myofibroblastic and plasma cells Etiology is unknown. Infection has been implicated Most patients are asymptomatic High FDG-uptake on PET imaging Chest Radiograph Nodule or mass Smooth, lobulated or spiculated margins May have calcification Page 31 of 43

32 Most commonly peripheral Chest CT Homogenous or heterogeneous attenuation nodule or mass Variable enhancement Usually associated with a bronchus Long-term follow-up tend to show no change in size or configuration Fig. 29: 24 year old female with pleuritic chest pain. A. Chest CT (lung window) reveals a spiculated left lower lobe mass with mild pleural thickening. MISCELLANEOUS CONDITIONS HEMATOMA Page 32 of 43

33 Hemorrhage within the alveolar and interstitial spaces Potentially fatal complication Hemoptysis may or may not be present Should be considered in patients with mass post-trauma or in patients on anticoagulation Chest Radiograph Oval, homogenous mass, usually subpleural, may persist for months or occasionally for years Chest CT Well circumscribed mass. High attenuation clot may be detectable. Ground glass opacity may be present surrounding the hematoma due to hemorrhage Fig. 30: 60 year old male with pulmonary hematoma due to anticoagulation for an aortic valve prosthesis. Chest CT (lung window). The well-circumscribed mass in the left mid lung shows peripheral ground glass opacity likely due to hemorrhage Page 33 of 43

34 Fig. 31: 60 year old male with pulmonary hematoma due to anticoagulation for an aortic valve prosthesis. Chest CT (mediastinal window). There is a round wellcircumscribed mass in the left mid lung. Air pockets are also seen within the lesion. An infected pulmonary hematoma was found at surgery. ROUNDED ATELECTASIS Focal rounded lung collapse, usually associated with focal pleural thickening or effusion. Associated with squelae of any inflammatory pleural disease Unchanged in size over several years Chest Radiograph Mass in association with pleural thickening and volume loss. Usiually in the posterior lower lobes Acute or obtuse angle with the pleura Page 34 of 43

35 Chest CT Round or oval mass, abutting the pleura Swirling of adjacent pulmonary vessels and bronchi into the edges of the opacity is very characteristic of this entity, eliminating the need for further work up in the majority of patients Fig. 32: Rounded atelectasis. Chest CT (lung window) demonstrate a mass like lesion associated with pleural thickening and architectural distortion. Pulmonary vessels swirling towards the mass (short arrow) are noted. Page 35 of 43

36 Fig. 33: Rounded atelectasis. The integrated PET/CT shows as expected in chronic collapse, negative FDG-avidity PULMONARY INFARCT 10% of embolic episodes result in pulmonary infarction More common in patients with underlying cardiopulmonary disease May develop immediately or after 2-3 days Chest Radiograph Pleural-based wedge-shaped or rounded opacity. Focal enlargement of the central pulmonary artery my be seen and surrounding olighemia is a described, but often an equivocal finding. The lesion maintains the same shape as it resolves Chest CT Confirms a wedge-shaped or rounded opacity (sometimes with truncated apex), abutting the pleural surface and convex borders. Emboli on CT angiogram are commonly seen and are clue for the diagnosis Page 36 of 43

37 Fig. 34: 35 year old male with acute pulmonary embolism and pulmonary infarction. CT lung window the mass (arrow) corresponding to a peripheral infarct. Page 37 of 43

38 Fig. 35: 35 year old male with acute pulmonary embolism and pulmonary infarction. CT shows a mass corresponding to a peripheral infarct in the RLL. Note the embolus in the right main pulmonary artery. PULMONARY ARTERY ANEURYSM May be congenital or acquired Most commonly mycotic aneurysms but also related to trauma or vasculitis (Behçet disease and Hughes-Stovin syndrome) Hemoptysis is the major complication Chest Radiograph Focal mass like lesion, that may surrounded by airspace opacities, in the case of infection or trauma. Chest CT Clearly shows the vascular nature of the lesion and therefore diagnostic. Page 38 of 43

39 Fig. 36: Mycotic aneurysm in a 30 year old male patient with leukemia and pulmonary aspergillosis.chest CT (mediastinal window) A giant aneurysm arises from the right interlobar pulmonary artery Page 39 of 43

40 Fig. 37: Mycotic aneurysm in a 30 year old male patient with leukemia and pulmonary aspergillosis. CT (volume- rendered image )nicely depicts the vascular nature of the lesion(arrow) VANISHING PSEUDOTUMOR Focal collection of fluid trapped in the fissures Associated with congestive heart failure and renal insufficiency Rapid resolution Chest Radiograph Solitary pulmonary mass like opacity with lenticular or biconvex contour along the course of the fissures. 75% occur in the minor fissure Page 40 of 43

41 Those that occur in the oblique or major fissure may only be seen well on the lateral view CT findings Localized lenticular shaped, fluidattenuation mass like opacity. Careful analysis confirms the relationship of the "mass" to the plane of the fissures Page 41 of 43

42 Fig. 38: Vanishing pseudotumor in a 73 year old male patient with history of ischemic cardiomyopathy. Chest radiograph (PA view). There is an oval soft tissue opacity in the region of the minor fissure. Fig. 39: Chest radiograph three days later, the mass like opacity is no longer identified, consistent with resolution of the loculated pleural effusion. Page 42 of 43

43 Conclusion The accurate interpretation of imaging findings requires a clinically oriented approach to diagnosis. For optimal patient care, in the case of mass-like lesions of the lungs, it is particularly important to become familiar with the various medical conditions that may mimic malignancies. Certain radiologic features are extremely helpful to reach an unequivocal diagnosis of a benign entity presenting as a mass: examples include fat attenuation for lipoid pneumonia, a feeding vessel for sequestration, enlarged feeding and draining vessels for AVM's, comet-tail bronchovascular bundles and adjacent pleural thickening for rounded atelectasis, mucous impaction and air trapping for bronchial atresia, and the air-crescent sign for mycetoma. Familiarity with the spectrum of nonneoplastic etiologies for solitary pulmonary masses in the appropriate clinical setting, will allow the radiologist to aid clinicians in designing the correct treatment plan. By identifying the subset of patients that would require additional work up, ie. with functional imaging and /or histologic sampling, radiologists can impact patient outcome. References 1. Hansell D, Armstrong P, Lynch D, et al. Imaging of Diseases of the Chest. 4th ed. Philadelphia: Elsevier Mosby; Fraser N, Müller N, Colman N, et al. Fraser and Pare's diagnosis of Diseases of the Chest. 4th ed. Philadelphia: Saunders; Müller N, Silva I. Imaging of the chest Volume I-II). First ed. Philadelphia: Saunders Elsevier; Müller N, Franquet T, Lee KS. Imaging of Pulmonary Infections. Fisrt ed.philadelphia: Lippincott Willimas& Wilkins; Webb R, Higgins Ch. Thoracic Imaging. 2nd ed.philadelphia: Lippincott Willimas&Wilkins; Giménez A, Franquet T, Prats R, et al. Unusual Primary Lung Tumors: A Radiologic-Pathologic Overview. Radiographics 2002; 22(3) Sekine I, Kodama T, Yokose T, et al. Rare pulmonary tumors: a review of 32 cases. Oncology 1998; 55: Lee KS, Müller N, Hale V, Newell J, et al. Lipoid pneumonia: CT findings. J Comput Assist Tomogr 1995; 19: Stark P, Eber CD, Jacobson F. Primary intra-thoracic malignant mesenchymal tumors: pictorial essay. J Thorac Imaging 1994; 9: Das Narla L, D,Newman B, Spottswood S, et al. Inflammatory Pseudotumor. Radiographics May : Personal Information Page 43 of 43