Medical Image of the Week: Typical Pulmonary CT Findings Following Radiotherapy

Figure 1. Panel A: CT chest, lung windows, demonstrating a spiculated nodule, biopsy proven adenocarcinoma in the right lower lobe (arrow). Panel B: Eight months post stereotactic radiation therapy, there has been development of focal consolidation, with air bronchograms, involving the right middle and lower lobes. Notice the volumetric appearance. The primary malignancy is no longer identified as such. Panel C: Thirteen months later the consolidation has evolved into an area of volume loss, containing bronchiectasis, and sharp contours as a result of organized fibrosis.

Radiation-induced lung disease (RILD) commonly develops in patients treated with radiation for intrathoracic and chest wall malignancies.

There are two distinct radiographic patterns:

1. Radiation pneumonitis which occurs within 4-12 weeks after completion of therapy, and is characterized by development ground-glass opacities and/or consolidation in and around the treated lesion. A somewhat nodular or patchy appearance may occur. Typically, the affected tissue conforms to the radiation ports and may cross fissures/lobes. There may be milder similar changes in the contralateral lung.
2. A chronic phase, known as radiation fibrosis, is noticeable about 6-12 months post treatment and may progress up to 2 years, after which the findings tend to stabilize. In this stage, the areas of consolidation undergo volume loss, architectural distortion and may contain traction bronchiectasis. Linear and band scarring may also be seen. In this phase, sharper demarcation between normal and irradiated lung parenchyma is commonly seen.

Special attention to the typical radiological characteristics and timeline, in most cases allows to distinguish RILD from potential superimposed infection, subacute inflammatory diseases, locally recurrent neoplasm and radiation-induced neoplasms.

Andrew Erickson MS IV¹, Berndt Schmidt MD², Veronica Arteaga MD², Diana Palacio MD²

¹Midwestern University – Arizona College of Osteopathic Medicine

²Division of Thoracic Radiology, Department of Medical Imaging. University of Arizona, Tucson (AZ)

Reference

1. Choi YW, Munden RF, Erasmus JJ, Joo Park K, Chung WK, Jeon SC, Park CK. Effects of radiation therapy on the lung: radiologic appearances and differential diagnosis. Radiographics. 2004 Jul;24(4):985-97. [CrossRef] [PubMed]

Cite as: Erickson A, Schmidt B, Arteaga V, Palacio D. Medical image of the week: typical pulmonary CT findings following radiotherapy. Southwest J Pulm Crit Care. 2017;15(3):120-1. doi: https://doi.org/10.13175/swjpcc112-17 PDF

Medical Image of the Week: Spontaneous Pneumothorax in End Stage Fibrotic Lung Disease

Figure 1. Chest x-ray showing moderate-sized right pneumothorax with a pigtail chest tube in place, diffuse reticular interstitial opacities.

Figure 2. Chest CT showing extensive centrilobular emphysema, moderate right pneumothorax with pigtail chest drain on the right, subpleural reticular opacities with peripheral and basilar preponderance suggesting interstitial fibrotic lung disease, and diffuse lung cysts - heterogenous in size.

A 61-year-old nonsmoking man with chronic obstructive lung disease, pulmonary hypertension, pulmonary fibrosis, hypertension, coronary artery disease with congestive heart failure, presented with recurrent pneumothorax, pneumomediastinum, extensive subcutaneous emphysema and bronchopleural fistula.

The patient reported ongoing symptoms of exertional dyspnea, fatigue, and coughing for years. His environmental exposures were notable for exposure to birds since early childhood. He had 6 cockatiels and 2 doves living inside his home and is directly responsible for their care. Former occupational exposures include painting and sandblasting. Family history was notable for early onset non specified lung disease in his father, and rheumatoid arthritis in his mother.

Lung function testing performed prior to the bronchopleural fistula revealed moderate obstructive ventilatory defect with severely limited DLCO. Chest x-ray (Figure 1) revealed a moderate-sized right pneumothorax with a pigtail chest tube in place and diffuse reticular interstitial opacities. His CT chest (figure 2) revealed extensive subcutaneous emphysema, diffuse lung cysts that are heterogenous in size, and subpleural reticular opacities with peripheral and basilar preponderance. Bronchoalveolar lavage revealed no infection, with predominant monocyte/ macrophages. Alpha-1 antitrypsin (A1AT) was normal, as were autoimmune panels. A hypersensitivity pneumonitis panel revealed positive IgG to Aureobasidium pullulans. A presumptive diagnosis of chronic hypersensitivity pneumonitis was made.

Spontaneous pneumothorax (SP), a potentially life-threatening complication, is defined by the accumulation of air in the pleural space with secondary lung collapse, and can be categorized as primary (without apparent lung disease) or secondary pneumothorax. While chronic obstructive pulmonary disease and Pneumocystitis jirovecii pneumonia are the most common causes of secondary spontaneous pneumothorax, other structural lung diseases such as fibrotic lung diseases have also been linked to SP. Interstitial lung diseases distort lung architecture and trigger formation of subpleural blebs that are susceptible to rupture leading to extra-alveolar air collection and air leakage in the pleural space. Presence of persistent air leak, as in our case, mandates surgical consideration to accelerate recovery and prevent recurrence of secondary SP.

Roula Altisheh MD and Tara Carr MD

Division of Pulmonary, Allergy, Critical Care and Sleep Medicine

Banner-University Medical Center

Tucson, AZ USA

References

1. Sahn S, Heffiner J. Spontaneous Pneumothorax. N Engl J Med 2000; 342:868-74 [CrossRef] [PubMed]
2. Onuki T, Ueda S, Yamaoka M, Sek iya Y, Yamada H, Kawakami N, Araki Y, Wakai Y, Saito K, Inagaki M, Matsumiya N. Primary and secondary spontaneous pneumothorax: prevalence, clinical features, and in-hospital mortality. Can Respir J. 2017: 6014967.  [CrossRef] [PubMed]
3. Koschel D, Handzhiev S, Cardoso C, Rolle A, Holotiuk O, Höffken G. Pneumomediastinum as a primary manifestation of chronic hypersensitivity pneumonitis. Med Sci Monit. 2011 Dec;17(12):CS152-5. [PubMed]
4. Ichinose J, Nagayama K, Hino H, et al. Results of surgical treatment for secondary spontaneous pneumothorax according to underlying diseases. Eur J Cardiothorac Surg. 2016;49(4):1132–6. [CrossRef] [PubMed]

Cite as: Altisheh R, Carr T. Medical image of the week: spontaneous pneumothorax in end stage fibrotic lung disease. Southwest J Pulm Crit Care. 2017;14(6):308-10. doi: https://doi.org/10.13175/swjpcc065-17 PDF 

Medical Image of the week: Chronic Pulmonary Histoplasmosis

Figure 1. Chest radiography showing upper lobe fibrosis and cavitation secondary to chronic histoplasmosis.

Histoplasmosis is endemic to the Midwest US and commonly causes an acute infection that presents as a subacute pneumonia.  In patients with underlying lung disease, particularly COPD, a subacute pneumonia can evolve into chronic pulmonary histoplasmosis and is characterized by persistent or recurrent pulmonary symptoms, progressive lung infiltrates, fibrosis, and cavitation. Upper lobe infiltrates and cavities are characteristic, resembling the findings in tuberculosis (Figure 1). Progression is manifested by cavity enlargement, increased fibrosis and bronchopleural fistulae.  Misdiagnosis delays therapy and can be catastrophic.  Histoplasmosis titers and sputum cultures are useful tests.  Bronchoscopy with bronchoalveolar lavage and transbronchial biopsy for culture may be needed when diagnosis remains elusive.

Kenneth S. Knox, MD¹ and Veronica A. Arteaga, MD²

¹Professor of Medicine

University of Arizona College of Medicine- Phoenix

Phoenix, AZ USA

²Associate Professor of Medicine

Medical Imaging

University of Arizona College of Medicine- Tucson

Tucson, AZ USA

Cite as: Knox KS, Artega VA. Medical image of the week: chronic pulmonary histoplasmosis. Southwest J Pulm Crit Care. 2017;14(3):88. doi: https://doi.org/10.13175/swjpcc022-17 PDF

February 2014 Imaging Case of the Month

Michael B. Gotway, MD

Department of Radiology

Mayo Clinic Arizona

Scottsdale, AZ

Clinical History: A 60-year-old man presented with a history of weight loss and dysphagia for about 2 weeks duration. There was a possible history of asthma accompanied by ongoing shortness of breath first noticed nearly 2 years ago. Frontal chest radiography (Figure 1) was performed.

Figure 1.  Frontal chest radiography.

Which of the following statements regarding the chest radiograph is most accurate? (Choose the correct answer to move to the next panel)

1. The chest radiograph shows a mass
2. The chest radiograph shows hilar and mediastinal lymph node enlargement
3. The chest radiograph shows multifocal consolidation
4. The chest radiograph shows multifocal, somewhat basal predominant linear opacities suggesting fibrosis
5. The chest radiograph shows multiple nodules

Reference as: Gotway MB. February 2014 imaging case of the month. Southwest J Pulm Crit Care. 2014;8(2):88-95. doi: http://dx.doi.org/10.13175/swjpcc010-14 PDF