February 2020 Imaging Case of the Month: An Emerging Cause for Infiltrative Lung Abnormalities

Prasad M. Panse MD*, Fiona F. Feller MD^†, Yasmeen M. Butt MD^‡, Michael B. Gotway MD*

Departments of *Radiology, ^†Medicine, and ^‡Laboratory Medicine

Mayo Clinic, Arizona

Phoenix, Arizona

Clinical History: A 25-year-old man with no previous medical history presented to the Emergency Room with complaints of worsening non-productive cough and fever to 102°F over the previous 7 days. The patient also complained of some nausea, vomiting, and generalized muscle aches. The patient denies rhinorrhea, sore throat, congestion, and diarrhea. The patient also illicit drug use, and drinks alcohol only occasionally. He said he previously smoked 1-2 packs-per day, having quit 6 months earlier.

The patient’s physical examination showed normal vital signs, although his respiration rate was approximately 18/minute. The physical examination showed some mild basilar crackles bilaterally, but was otherwise entirely within normal limits.

Basic laboratory data showed a white blood cell count near the upper of normal= 10.3 x 10⁹ / L (normal, 4–10.8 x 10⁹/L) with a normal platelet count and no evidence of anemia, normal serum chemistries and renal function parameters, and normal liver function tests. The patient was referred for chest radiography (Figure 1).

Figure 1. Frontal (A) and lateral (B) chest radiography at presentation.

Which of the following statements regarding the chest radiograph is most accurate? (Click on the correct answer to be directed to the second of fourteen pages)

1. The chest radiograph shows bilateral consolidation
2. The chest radiograph shows findings suggesting increased pressure pulmonary edema
3. The chest radiograph shows mediastinal and peribronchial lymph node enlargement
4. The chest radiograph shows mild perihilar infiltration
5. The chest radiograph shows normal findings

Cite as: Panse PM, Feller FF, Butt YM, Gotway MB. February 2020 imaging case of the month: an emerging cause for infiltrative lung abnormalities. Southwest J Pulm Crit Care. 2020;20(2):43-58. doi: https://doi.org/10.13175/swjpcc004-20 PDF 

Medical Image of the Month: Hot Tub Lung

Figure 1. Chest radiograph showing diffuse micronodular disease.

Figure 2. Representative images from the thoracic CT scan confirming diffuse micronodular disease with a centrilobular distribution.

Figure 3. Lung biopsy from VATS showing granulomas. Panel A: Low power view. Panels B & C: High power views.

The patient is a 65-year-old man with progressively worsening shortness of breath for 2 months. He had a past medical history of type 2 diabetes mellitus, hypertension, hypothyroidism and a 40 pack-year history of smoking. He suffered from chronic neck pain and sought relief by spending up to 6 hours daily in a hot tub. Chest x-ray (Figure 1) showed numerous small nodules which were confirmed on thoracic CT (Figure 2). The nodules spared the pleural space consistent with a centrilobular distribution. Bronchoscopy with bronchoalveolar lavage grew Mycobacterium avium intracellulare (MAC) and a lung biopsy obtained by video-assisted thorascopic surgery (VATS) showed non-caseating granulomas (Figure 3). Culture of the hot tub water also grew MAC.  He was advised to stop using the hot tub and was treated with prednisone, clarithromycin, rifampin and ethambutol. He rapidly improved though he stopped his therapy after about 3 weeks due to intolerance.  He continued to do well and was asymptomatic when last seen.

Hot tub lung may represent either an infectious process or a hypersensitivity pneumonitis to MAC inhaled from the hot tub. Improvement is usually seen with prednisone, anti-MAC therapy or both (1). The thoracic CT findings are consistent with subacute hypersensitivity pneumonitis including areas of ground-glass attenuation, centrilobular nodules, and air trapping on expiratory images (2). Granulomas, a compact collection of macrophages, are a nonspecific finding seen in both infectious (mycobacteria and fungi) and noninfectious lung diseases (sarcoidosis, hypersensitivity pneumonitis, hot tub lung, and several others) (3). In our patient’s case the clinical history, radiologic findings, lung histology and rapid improvement with removal of MAC exposure are all consistent with hot tub lung.

Allen R. Thomas, MD

Phoenix VA

Phoenix, AZ USA

References

1. Khoor A, Leslie KO, Tazelaar HD, Helmers RA, Colby TV. Diffuse pulmonary disease caused by nontuberculous mycobacteria in immunocompetent people (hot tub lung). Am J Clin Pathol. 2001 May;115(5):755-62. [CrossRef] [PubMed]
2. Hartman TE, Jensen E, Tazelaar HD, Hanak V, Ryu JH.CT findings of granulomatous pneumonitis secondary to Mycobacterium avium-intracellulare inhalation: "hot tub lung". AJR Am J Roentgenol. 2007 Apr;188(4):1050-3. [CrossRef] [PubMed]
3. Hutton Klein JR, Tazelaar HD, Leslie KO, Colby TV. One hundred consecutive granulomas in a pulmonary pathology consultation practice. Am J Surg Pathol. 2010 Oct;34(10):1456-64. [CrossRef] [PubMed]

Cite as: Thomas AR. Medical image of the month: hot tub lung. Southwest J Pulm Crit Care. 2018;17(3):93-4. doi: https://doi.org/10.13175/swjpcc077-18 PDF 

Medical Image of the Week: Headcheese Sign

Figure 1. Representative image from thoracic CT scan showing ground glass opacities, most prominent in the lower lung fields bilaterally with air trapping.

A 95-year-old woman with a past medical history of breast cancer and mastectomy presented with fevers, cough productive of sputum and progressive dyspnea for 2 weeks. She denies any recent travel or sick contacts but has bird at home since last 10 years. She was afebrile but tachypneic with respiratory rate of 25 and sPO2 of 86% on room air. Her initial chest examination reveals coarse rhonchi in both lungs. Labs were significant for a sodium of 118 mEq/L, leukocytosis to 18,000 cells/mcL without peripheral eosinophilia. Arterial blood gas showed pO2 of 55 mm Hg, pCO2 of 48 mm Hg and pH of 7.44. An initial chest X-ray was positive for extensive bilateral pulmonary infiltrates predominantly in the mid and lower lungs with areas of airspace consolidation. Her urine Streptococcus pneumoniae antigen was negative as well as rapid influenza and a respiratory syncytial virus panel. The high resolution thoracic CT showed scattered ground glass opacities, most prominent in the lower lung fields bilaterally (Figure 1). Small more focal consolidative opacities are seen in the right upper lobe. As there was a juxtaposition of low, normal and high-attenuated area of CT scan, characteristic of the headcheese sign.

The head cheese sign is indicative of a mixed obstructive and infiltrative process (1). The low attenuated regions reflect air trapping suggestive of obstructive small airway disease and vasoconstriction due to hypoxia (2). Expiration CT may be needed to enhance low attenuation areas. This airway pathology leads to mosaic attenuation on HRCT. The most common cause of this radiological sign is hypersensitivity pneumonitis (3). As our patient had a long exposure to bird, it was probably the cause of her lung pathology. Other causes of the headcheese sign such as sarcoidosis, bronchiolitis, mycoplasma pneumonia or desquamative interstitial pneumonitis should be considered.

Learning Points:

1. Headcheese is a radiological sign suggestive of hypersensitivity pneumonitis as most common cause.
2. Occupation or any animal exposure history will be most useful in this scenario.
3. The clinician should rule out other causes such as an infectious etiology or sarcoidosis.

Ajay Adial MD, Danial Arshed MD, Lourdes Sanso MD, and Asma Iftikhar MD

Pulmonary/Critical Care Medicine

New York-Presbyterian/Queens

New York, NY USA

References

1. Webb WR. Thin-section CT of the secondary pulmonary lobule: anatomy and the image--the 2004 Fleischner lecture. Radiology. 2006 May;239(2):322-38. [CrossRef] [PubMed]
2. Hirschmann JV, Pipavath SN, Godwin JD. Hypersensitivity pneumonitis: a historical, clinical, and radiologic review. Radiographics. 2009 Nov;29(7):1921-38. [CrossRef] [PubMed]
3. Patel RA, Sellami D, Gotway MB, Golden JA, Webb WR. Hypersensitivity pneumonitis: patterns on high-resolution CT. J Comput Assist Tomogr. 2000 Nov-Dec;24(6):965-70. [CrossRef] [PubMed]

Cite as: Adial A, Arshed D, Sanso L, Iftikhar A. Medical image of the week: headcheese sign. Southwest J Pulm Crit Care. 2018;16(4):192-3. doi: https://doi.org/10.13175/swjpcc040-18 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 

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

Medical Image of the Week: Expiratory Imaging Accentuates Mosaic Attenuation

A 66 year old female presented with cough, fever and marked shortness of breath.   Infectious work up was found to be negative.  An inspiratory high resolution thoracic CT (HRCT) image (A) shows faint groundglass and mosaic lung attenuation with subtle centrilobular ill-defined nodules.  However, an image obtained on expiration (B) shows more obvious mosaic attenuation which suggesting air-trapping. Due to progressive dyspnea, a lung biopsy was performed and revealed a bronchiolocentric cellular interstitial pneumonia with non-caseating granuloma consistent with subacute hypersensitivity pneumonitis.

Veronica A. Arteaga, MD and Kenneth S. Knox, MD

Divisions of Thoracic Imaging and Pulmonary/Critical Care Medicine

University of Arizona

Tucson, Arizona

Reference as: Arteaga VA, Knox KS. Medical image of the week: expiratory imaging accentuates mosaic attenuation. Southwest J Pulm Crit Care. 2013;6(5):245. PDF