Case of the Day Chest Darin White MDCM FRCPC Department of Radiology, Mayo Clinic 76 th Annual Scientific Meeting Canadian Association of Radiologists Montreal, QC April 26, 2013 2013 MFMER slide-1
Disclosures Relevant Financial Disclosures None Off Label Use Disclosures None 2013 MFMER slide-2
History 46 year-old male Progressive dyspnea on exertion New small amounts of hemoptysis for 2 months 2013 MFMER slide-3
2013 MFMER slide-4
Differential Diagnosis Unilateral Pulmonary Interstitial Pattern ACUTE Infection Edema Aspiration Resolving hemorrhage Airspace opacity superimposed on already abnormal lung (i.e. emphysema, fibrosis, etc.) CHRONIC Recurrent aspiration/ infection Radiation fibrosis Lymphangitic carcinomatosis Pulmonary venous obstruction Unilateral lung transplant Other rare 2013 MFMER slide-5
2013 MFMER slide-6
Differential Diagnosis NEOPLASTIC Bronchogenic carcinoma Metastatic disease Lymphoma NON-NEOPLASTIC Fibrosing mediastinitis IgG4-related disease 2013 MFMER slide-7
Subsequent Evaluation 18F-FDG PET/CT Mildly increased metabolic activity in subcarinal and para-aortic lymph nodes (SUV max = 3.6) Low level 18F-FDG activity in region of left hilar soft tissue thickening EBUS-guided Biopsy Negative for malignancy Serology Histoplasma capsulatum antibody positive 2013 MFMER slide-8
Answer Fibrosing Mediastinitis 2013 MFMER slide-9
Fibrosing Mediastinitis Also referred to as mediastinal fibrosis or sclerosing mediastinitis Rare benign proliferation of fibrous tissue within the mediastinum Pathologically, a spectrum from loose fibromyxoid tissue to dense collagen with a variable inflammatory cellular infiltrate 2013 MFMER slide-10
Fibrosing Mediastinitis Etiology Granulomatous infection Histoplasma capsulatum Tuberculosis, actinomycosis, blastomycosis, aspergillosis Non-infectious granulomatous disease Sarcoidosis, silicosis, Behcet s Immunologic/Autoimmune Collagen vascular disease, IgG4- related disease, multisystem fibrosis Iatrogenic methysergide, radiation Trauma Idiopathic Malignancy 2013 MFMER slide-11
Fibrosing Mediastinitis Presentation Variable age at presentation = Signs and symptoms related to compression or obstruction of mediastinal or hilar structures Cough, dyspnea, recurrent infection, chest pain, hemoptysis, superior vena cava syndrome, dysphagia, hoarseness, diaphragmatic paralysis, Horner syndrome, chylothorax Constitutional symptoms Fever, weight loss, malaise 2013 MFMER slide-12
Fibrosing Mediastinitis Imaging Chest Radiographs mediastinal widening distortion of mediastinal lines and stripes hilar enlargement +/- calcification Sequelae: airway narrowing, postobstructive atelectasis/ consolidation pulmonary venous hypertension, pulmonary edema vascular asymmetry, pulmonary infarcts 2013 MFMER slide-13
Fibrosing Mediastinitis Imaging CT infiltrative mediastinal/hilar soft tissue thickening or mass focal (82%) or diffuse (18%) calcification (60-90%) variable enhancement Sequelae compression/obstruction of central airways, central vessels, esophagus atelectasis, consolidation, edema, infarcts 2013 MFMER slide-14
Fibrosing Mediastinitis Imaging MRI typically intermediate T1 and heterogeneous T2 signal intensity often regions of T2 hypointensity inferior to CT for detection of calcification heterogeneous enhancement postgadolinium Sequelae as demonstrated on CT 2013 MFMER slide-15
Fibrosing Mediastinitis Imaging Nuclear Medicine 18-FDG PET variable metabolic activity within and between lesions Ventilation/Perfusion perfusion defects reflecting pulmonary arterial or venous obstruction lobar/segmental ventilation defects or air trapping reflecting airway involvement Ventilation Perfusion 2013 MFMER slide-16
Summary Fibrosing mediastinitis should be considered in the setting of localized mediastinal soft tissue thickening associated with vascular and/or airway compromise. Accompanying calcification further suggests the diagnosis. In the correct clinical setting, such as positive Histoplasma capsulatum serology and no known malignancy, CT findings may obviate the need for biopsy. 2013 MFMER slide-17
Questions? white.darin@mayo.edu 2013 MFMER slide-18
Review At the conclusion of this session, participants should be able to: 1. Provide a differential diagnosis for a unilateral pulmonary interstitial pattern. (CanMEDS Roles: Medial Expert) 2. Describe the typical imaging features and differential diagnosis of fibrosing mediastinitis. (CanMEDS Roles: Medical Expert) 3. List at least four causes of fibrosing mediastinitis. (CanMEDS Roles: Medical Expert) 2013 MFMER slide-19
References McNeeley MF, Chung JH, Bhalla S, Godwin JD. Imaging of granulomatous fibrosing mediastinitis. AJR. 2012; 199(2):319-327. Rossi SE, McAdams HP,Rosado-de-Christenson ML, Franks TJ, Galvin JR. Fibrosing mediastinitis. Radiographics. 2001; 21(3): 737-757. Franquet T. Mediastinitis. In: Muller NL, Silva CIS, eds. Imaging of the Chest. Philadelphia, PA: Saunders Elsevier; 2008: 1457-1472. 2013 MFMER slide-20