Medical Image of the Month: Mounier-Kuhn Syndrome

Figure 1. AP chest x-ray showing significant tracheomegaly (diameter 30.8 mm), bilateral interstitial infiltrates with dense consolidation more at the lower lobes (left>right).

Figure 2. Axial thoracic CT in lung windows (A-D) and soft tissue windows (E-F). Sagittal CT in soft tissue windows (G-H). A: tracheal diameters in 2 dimensions (coronal 30.4 mm, sagittal 37.6 mm), para-septal emphysema (yellow arrows). B: showing tracheomegaly (23.2 x 34.3 mm) and para-septal emphysema changes (yellow arrows. C: enlarged mainstem bronchi diameters (right mainstem 22.3 x 30.6 mm, left mainstem 24.4 x 16.0 mm). In addition to central bronchiectatic changes (red arrows), left lower lobe consolidative changes (blue arrow). D: dense left lower lobe consolidation and para-septal emphysema. E: Significant tracheomegaly (31.5 x 41.a mm) and dilated esophagus (orange arrow). F: Significant tracheomegaly and dilated esophagus.

Figure 3. A: Sagittal CT scan (soft tissue window) showing significant tracheomegaly (sagittal diameter 35.8 mm). B: Sagittal CT chest (lung window) showing significant tracheomegaly, multiple tracheal diverticuli (green arrows) on the upper posterior tracheal wall.

Figure 4. Pulmonary function testing.

A 52-year-old non-smoking, Caucasian male patient with a past medical history of reported chronic obstructive pulmonary disease (COPD), recurrent lower respiratory tract infections, prior history of pneumothorax, and dysphagia presented with fevers and shortness of breathing associated with a productive cough for one week. Clinically, he was mildly tachypneic and chest auscultation revealed crackles bilaterally - more prominent at the left base. A chest radiograph (Figure 1) showed bilateral lower lobe pulmonary opacities (left more than right). Computed tomography (CT) of the chest demonstrated airspace disease in the lower lobes in addition to significant tracheobronchomegaly along with paraseptal emphysema and central bronchiectatic changes (Figures 2 and 3). Upper posterior tracheal wall diverticulae were also noted (Figure 3). Serum α₁-antitrypsin level and serum immunoglobulins, including IgE levels, were normal. Our patient declined performing diagnostic bronchoscopy. He had a pulmonary function test performed few months prior to his hospital admission which showed combined mild obstructive/restrictive pattern (Figure 4). He responded well to empiric antibiotics and chest percussion therapy. He was discharged in stable condition.

Discussion

On the basis of above findings, a diagnosis of Mounier-Kuhn syndrome complicated by pneumonia was made. The syndrome was first described by P. Mounier-Kuhn in 1932 (1). The diagnosis is usually made when the tracheal diameter is greater than 3 cm on a CT chest (measured 2 cm above the aortic arch) (2). Other diagnostic criteria include a mainstem bronchial diameter of 20-24 mm (right) and 15-23 mm (left) (3). Our patient’s tracheal diameter was around 37 mm. Both mainstem bronchi were dilated.

The abnormal tracheobronchial dilatation in this syndrome is attributed to atrophy of the muscular and elastic tissues in the tracheal and the bronchial walls (3). Hence, in addition to tracheobronchomegaly, these patients can also develop tracheal diverticulosis along with varicose and cystic bronchiectasis (3). These patients usually present in the 3rd or 4th decade of life with nonspecific respiratory symptoms including recurrent bronchitis and subsequently end up being misdiagnosed with COPD (3).

Three subtypes of this syndrome had been described. Subtype 1 has symmetric dilation of the trachea and mainstem bronchi. Subtype 2 demonstrates tracheal dilation and tracheal diverticula. Subtype 3 has diverticular and saccular structures extending to the level of the distal bronchi (3). Our patient likely fits subtype 3 of this syndrome. Overall, treatment is supportive - usually with antibiotics, physiotherapy and postural drainage. In rare instances, tracheal stenting has been used (4). Special consideration should be taken post intubation as achieving good cuff seal can be potentially challenging.

Dysphagia has not been well documented in this syndrome and could be a coincidental finding in our case. However, theoretically, the etiology of this patient’s dysphagia could be secondary to extrinsic compression of the anterior esophageal wall by his markedly dilated trachea. Historically, he underwent multiple esophageal dilatations and at least one Botox injection over the last 5 years without any significant improvement.

Abdulmonam Ali MD and Naga S. Sirikonda MD

Pulmonary and Critical Care

Good Samaritan Hospital

Mount Vernon, Illinois

References

1. Mounier-Kuhn P. "Dilatation de la trachee: constatations, radiographiques et bronchoscopies." Lyon Med. 1932;150:106-9.
2. Menon B, Aggarwal B, Iqbal A. Mounier-Kuhn syndrome: report of 8 cases of tracheobronchomegaly with associated complications. South Med J. 2008;101(1):83-7. [CrossRef] [PubMed]
3. Falconer M, Collins DR, Feeney J, Torreggiani WC. Mounier-Kuhn syndrome in an older patient. Age Ageing. 2008;37(1):115-6. [CrossRef] [PubMed]
4. Schwartz M, Rossoff L. Tracheobronchomegaly. Chest 1994;106(5):1589-90. [CrossRef] [PubMed]

Cite as: Ali A, Sirikonda NS. Medical image of the month: Mounier-Kuhn syndrome. Southwest J Pulm Crit Care. 2019;19(2):73-5. doi: https://doi.org/10.13175/swjpcc044-19 PDF 

Medical Image of the Week: Infected Emphysematous Bulla

Figure 1. Portable AP chest X-ray revealing dense opacity within the lingula of left lung.

Figure 2. Thoracic CT with contrast showing lobar consolidation with increased lucency compatible with emphysema.

Figure 3. (A) Chest CT one year prior demonstrating severe emphysema. (B) Chest CT on admission showing new fluid-filled bulla (red arrow) in the setting pneumococcal pneumonia.

A 65 year-old man with chronic obstructive lung disease (COPD), hypertension and alcohol abuse presented to the emergency department with complaints of feeling unwell and shortness of breath. He was tachycardic but otherwise hemodynamically stable, afebrile, and requiring 3 liters/min supplemental oxygen. Pertinent initial laboratory findings revealed a neutrophilic predominant leukocytosis (WBC 37.8 x 10³ micro/L) with lactic acidosis (2.7 mMol/L). Chest radiograph showed a dense opacity within the region of the lingula (Figure 1). Follow-up CT chest confirmed a consolidation likely representing lobar pneumonia in the setting of severe bullous emphysema (Figure 2). A large fluid-containing emphysematous bulla (Figure 3) was present which was not visualized one year prior. 

He was started on broad spectrum antibiotics after peripheral blood cultures were drawn which revealed Streptococcus pneumoniae. Broad spectrum antibiotics were discontinued and patient was started on intravenous ceftriaxone 2g every 24 hours. He improved clinically and was discharged home after 4 days.

Pneumococcal pneumonia remains the most common cause of community-acquired pneumonia and accounts for nearly 66% of all bacteremic pneumonias (1,2). Our patient had multiple risk factors for developing pneumococcal pneumonia including alcohol abuse, COPD, and history of cigarette smoking. Pneumococcal pneumonia often causes dense consolidation within the lung in a well-defined lobar or segmental distribution. In emphysema areas of lucency may be seen within the consolidation which may mimic other processes such as necrosis. The pathogenesis of fluid accumulation in an emphysematous bulla is not well understood but can be associated with severe lung infection (3). Percutaneous drainage is not recommended and bronchoscopy is not usually required unless there is another indication (3). Antibiotic therapy in those who are asymptomatic has not shown to add any benefit in resolution or preventing infection (3).

Norman Beatty MD¹, Kyle McKeown MPH², Kelly M. Hager MPH², and Stephen J. Scholand MD³

¹ Department of Medicine, Banner-University Medical Center South, Tucson, AZ USA

² University of Arizona College of Medicine, Tucson, AZ USA

³ Division of Infectious Diseases, Department of Medicine, MidState Medical Center, Meriden, CT USA

References

1. Torres A, Peetermans WE, Viegi G, Blasi F. Risk factors for community-acquired pneumonia in adults in Europe: a literature review. Thorax. 2013 Nov;68(11):1057-65. [CrossRef] [PubMed]
2. Fine MJ, Smith MA, Carson CA, Mutha SS, Sankey SS, Weissfeld LA, Kapoor WN. Prognosis and outcomes of patients with community-acquired pneumonia. A meta-analysis. JAMA. 1996 Jan 10;275(2):134-41. [CrossRef] [PubMed]
3. Chandra D, Rose SR, Carter RB, Musher DM, Hamill RJ. Fluid-containing emphysematous bullae: a spectrum of illness. Eur Respir J. 2008 Aug;32(2):303-6. [CrossRef] [PubMed]

Cite as: Beatty N, McKeown K, Hager KM, Scholand SJ. Medical image of the week: infected emphysematous bulla. Southwest J Pulm Crit Care. 2016;14(1):37-8. doi: https://doi.org/10.13175/swjpcc006-17 PDF 

August 2016 Imaging Case of the Month

Michael B. Gotway, MD  

Department of Radiology

Mayo Clinic Arizona

Scottsdale, Arizona USA 

Imaging Case of the Month CME Information  

Members of the Arizona, New Mexico, Colorado and California Thoracic Societies and the Mayo Clinic are able to receive  0.25 AMA PRA Category 1 Credits™. Completion of an evaluation form is required to receive credit and a link is provided on the last panel of the activity.

0.25 AMA PRA Category 1 Credit(s)™

Estimated time to complete this activity: 0.25 hours

Lead Author(s): Michael B. Gotway, MD. All Faculty, CME Planning Committee Members, and the CME Office Reviewers have disclosed that they do not have any relevant financial relationships with commercial interests that would constitute a conflict of interest concerning this CME activity. 

Learning Objectives:
As a result of this activity I will be better able to:    

1. Correctly interpret and identify clinical practices supported by the highest quality available evidence.
2. Will be better able to establsh the optimal evaluation leading to a correct diagnosis for patients with pulmonary, critical care and sleep disorders.
3. Will improve the translation of the most current clinical information into the delivery of high quality care for patients.
4. Will integrate new treatment options in discussing available treatment alternatives for patients with pulmonary, critical care and sleep related disorders.

Learning Format: Case-based, interactive online course, including mandatory assessment questions (number of questions varies by case). Please also read the Technical Requirements.

CME Sponsor: University of Arizona College of Medicine at the Arizona Health Sciences Center.

Current Approval Period: January 1, 2015-December 31, 2016

Clinical History: A 47 year-old white man presented with a history of worsening shortness of breath over the past few months. When questioned, the patient indicated that his activity tolerance had probably been slow decreasing over a relatively long period of time, but had become more pronounced recently.

Laboratory data, include white blood cell count and serum chemistries were within normal limits. Oxygen saturation on room air was 93%.

Frontal chest radiography (Figure 1) was performed.

Figure 1. Frontal and lateral chest radiography. Which of the following statements regarding the chest radiograph is most accurate? (Click on the correct answer to proceed to the second of seven panels)

1. The frontal chest radiograph appears normal
2. The frontal chest radiograph shows abnormal mediastinal contours
3. The frontal chest radiograph shows abnormally increased lung volumes
4. The frontal chest radiograph shows bilateral linear and reticular abnormalities
5. The frontal chest radiograph shows pneumothorax

Cite as: Gotway MB. August 2016 imaging case of the month. Southwest J Pulm Crit Care. 2016;13(2):54-62. doi: http://dx.doi.org/10.13175/swjpcc072-16 PDF

Medical Image of the Week: Bullous Emphysema

Figure 1. Chest radiograph showing hyperinflated lungs.

Figure 2. Panel A: Coronal view of chest computed tomography (CT) in  lung widows showing multiple large lucent spaces of lung parenchyma destruction interspersed normal lung tissue. Panel B: Axial view of chest CT showing coronal narrowing of the trachea with widening of the sagittal diameter (arrow). This is known as a saber sheath trachea which is pathognomonic of chronic obstructive pulmonary disease.

A 63-year-old gentleman, with a history of 90-pack-years of smoking and stage IV chronic obstructive pulmonary disease was receiving home oxygen at 2 L/min at baseline. He has had multiple prior hospital admissions for respiratory failure. Over the past 2 weeks he has had increased production of sputum, associated with worsening shortness of breath. He is on fluticasone-salmeterol inhaler, albuterol inhaler, and tiotropium as an outpatient.

On examination, he was hemodynamically stable, SpO2 was 92% on 4L/min of oxygen. He was in obvious respiratory distress, in a tripod position with tachypnea and using respiratory accessory muscles. Lung examination revealed diffuse expiratory wheezing.

Chest radiograph shows severe emphysema (Figure 1). Chest computed tomography showed diffuse centrilobular and bullous emphysema (Figure 2).  He was treated as an acute severe exacerbation of COPD and was eventually discharged to follow-up with the pulmonary clinic.

Emphysema is defined as alveolar destruction and airspace enlargement distal to the terminal bronchiole. There are subclassifications of emphysema based on its distribution within the secondary lobule (1). Bullae are defined as an air-filled space, greater than 1 cm in diameter, usually as a result of emphysematous destruction. Indications for bullectomy include patient symptoms, isolated bullae occupying > 30% of the hemithorax or complications arising from bullae (2).

Kai Rou Tey, MD¹; Akinbola Ajayi-Obe¹, MD; and Naser Mahmoud, MD²

¹Department of Internal Medicine, South Campus

²Department of Pulmonary, Critical Care, Allergy and Sleep

University of Arizona College of Medicine

Tucson, AZ

References

1. Terminology, Definitions, and Classification of Chronic Pulmonary Emphysema and Related Conditions: A Report of the Conclusions of a Ciba Guest Symposium. Thorax. 1959;14(4):286-299.
2. van Berkel V, Kuo E, Meyers BF. Pneumothorax, bullous disease, and emphysema. Surg Clin North Am. 2010 Oct;90(5):935-53. [CrossRef] [PubMed]

Cite as: Tey KR, Ajayi-Obe A, Mahmoud N. Medical image of the week: bullous emphysema. Souhwest J Pulm Crit Care. 2016 Apr;12(4):147-8. doi: http://dx.doi.org/10.13175/swjpcc157-15 PDF

Medical Image of the Week: Panlobular Emphysema

Figure 1. PA chest radiograph showing predominately lower lobe emphysematous changes.

A 60 year old female, non-smoker with a past medical history of chronic rhinosinusitis with nasal polyps presented with an eight year history of productive cough and dyspnea. Previous treatment with inhaled corticosteroids, courses of systemic corticosteroids and antibiotics provided modest improvement in her symptoms. Pulmonary function testing revealed a severe obstructive ventilatory defect without significant bronchodilator response and reduced diffusing capacity (DLCO). Chest x-ray surprisingly revealed lower lobe predominant emphysematous changes (Figure 1). Alpha-1-antitrypsin level was within normal range at 137 mg/dL.

Panlobular emphysema represents permanent destruction of the entire acinus distal to the respiratory bronchioles and is more likely to affect the lower lobes compared to centrilobular emphysema (1). Panlobular emphysema is associated with alpha-1-antitrypsin deficiency, intravenous drug abuse specifically with methylphenidate and methadone, Swyer-James syndrome, and obliterative bronchiolitis. Whether this pattern is seen as part of normal senescence in non-smoking individuals remains controversial (2). Panlobular emphysema may represent a phenotypically more severe disease than centrilobular emphysema and may coexist along a continuum with centrilobular emphysema (3).

Ashish Mathur MD and Tara Carr MD

Division of Pulmonary, Allergy, Critical Care and Sleep Medicine

University of Arizona College of Medicine

Tucson, Arizona

References

1. Litmanovich D, Boiselle PM, Bankier AA. CT of pulmonary emphysema-current status, challenges, and future directions. Eur Radiol. 2009;19(3): 537-51. [CrossRef] [PubMed]
2. Takahashi M, Fukuoka J, Nitta N et al. Imaging of pulmonary emphysema: a pictorial review. Int J Chron Obstruct Pulmon Dis. 2008;3(2):193-204. [PubMed]
3. Finkelstein R, Ma HD, Ghezzo H, Whittaker K, Fraser RS, Cosio MG. Morphometry of small airways in smokers and its relationship to emphysema type and hyperresponsiveness. Am J Respir Crit Care Med. 1995;152(1):267-76. [CrossRef] [PubMed]

Reference as: Mathur A, Carr T. Medical image of the week: panloubular emphysema. Southwest J Pulm Criti Care. 2015;11(2):86-7. doi: http://dx.doi.org/10.13175/swjpcc081-15 PDF

Medical Image of the Week: Aspergilloma

Figure 1.  Axial thoracic computed tomography (CT) image showing emphysematous disease throughout with prominent bullous disease in the upper lobes.  Areas of consolidation were concerning for infection.  Large cavitation with particulate matter (arrow) was seen in the left upper lobe. 

A 69-year-old woman, a current smoker, with very severe chronic obstructive pulmonary disease and prior atypical mycobacterium, was found unresponsive by her family and intubated in the field by emergency medical services for respiratory distress.  Her CT thorax showed severe emphysematous disease, apical bullous disease, and a large left upper lobe cavitation with debris (Figure 1).  She was treated with broad-spectrum antibiotics and anti-fungal medications.  Hemoptysis was never seen.  Sputum cultures over a span of two weeks repeatedly showed Aspergillus fumigatus and outside medical records confirmed the patient had a known history of stable aspergilloma not requiring therapy. 

Aspergillomas usually arises in cavitary areas of the lung damaged by previous infections.  The fungus ball is a combination of colonization by Aspergillus hyphae and cellular debris.  Individuals with aspergillomas are usually asymptomatic or have mild symptoms (chronic cough) and do not require treatment unless it begins to invade into the cavity wall.  When bleeding complications arise, surgical resection is curative but in high-risk patients, embolization may be considered as a stabilizing measure. 

Wendy Hsu, MD, Carmen Luraschi-Monjagatta, MD and Gordon Carr, MD

Division of Pulmonary and Critical Care Medicine

University of Arizona 

Tucson, AZ 

Reference 

Kousha M1, Tadi R, Soubani AO. Pulmonary aspergillosis: a clinical review. Eur Respir Rev. 2011;20(121):156-74. [CrossRef] [PubMed]

Reference as: Hsu W, Luraschi-Monjagatta C, Carr G. Medical image of the week: aspergilloma. Southwest J Pulm Crit Care. 2014;8(5):282-3. doi: http://dx.doi.org/10.13175/swjpcc044-14 PDF 

January 2012 Case of the Month

Michael B. Gotway, MD

Associate Editor Imaging

Clinical History

A 69-year-old woman with no significant past medical history presented with progressive shortness of breath. A chest radiograph (Figure 1) was obtained.

Figure 1. Frontal chest radiograph.

How would you describe the findings on the chest radiograph (Figure 1)?

1. Multifocal consolidation
2. Blunting of the costophrenic angles suggesting pleural effusion
3. Multifocal reticulonodular opacities
4. Bilateral cavitary lung consolidation
5. Miliary nodular opacities

Reference as: Gotway MB. January 2012 case of the month. Southwest J Pulm Crit Care 2012;4:12-18. (Click here for a PDF version)