MyPACS.net: Radiology Teaching Files > Case 61899562

Last visited 09/08/2012 Cavitary mass
Contributed by: Aaron Betts, Resident, Brooke Army Medical Center, Texas, USA.
Patient: 57 year old female
History: 57 year-old female smoker with history of chronic cough. Patient has a history of a cavitary pulmonary nodule of the right upper lobe, previous percutaneous biopsy showing granulomatous changes and hypercellular interstitial infiltrates, presumed diagnosis of Langerhans cell histiocytosis. New cavitary nodule of the left upper lobe. Patient underwent PET-CT, which showed hypermetabolic activity in the right upper lobe nodule. Percutaneous re-sampling of the right upper lobe cavitary nodule was performed.
Images:[small]larger

Fig. 1: Axial CT August 2008

Fig. 2: Axial CT - January 2009

Fig. 3: Axial CT - March 2010

Fig. 4: Axial CT - March 2011.

Fig. 5: Axial CT - August 2011

Fig. 6: Axial CT - August 2011
Findings: RUL cavitary nodule is seen in a background of advanced centrilobular emphysematous changes. There RUL nodule is progressively increasing in size. New LUL cavitary nodule has developed.
Diagnosis: Non-tuberculous mycobacterial infection (Mycobacterium avium-intracellulare), negative for malignancy -- biopsy/culture proven.
Discussion:

Non-tuberculous mycobacterial (NTMB) pulmonary infection is a chronic pulmonary infection with variable presentation clinically and on imaging. While these organisms are ubiquitous and exposure is common. However, infection rates after exposure are low. Most cases of chronic NTMB pulmonary infection occur in patients over the age of 50 with underlying pulmonary disease, such as COPD, or patients with immunologic disease. The most common organisms are M avium-intracellulare and M kansasii. Classic infection pattern is indistinguishable from post-primary tuberculosis, with upper lobe cavitary nodules commonly seen. This pattern is more common in elderly men. The non-classic infection is typically seen in elderly women with chronic cough, sometimes called the "Lady Windermere Syndrome." The non-classic infection pattern typically shows bronchiectasis, centrilobular nodules and tree-in-bud opacities, with predilection for the lingula and right middle lobe. Cavitation is not seen in the non-classic presentation. 

 

This case presents a classic pattern of NTMB infection, proven to be M avium intracellulare. While the classic form is more common in men with COPD, this patient's underlying smoking history and COPD may have predisposed her to the classic presentation rather than the non-classic form, which is more common in females. 

References:
  1. Erasmus JJ, McAdams HP, Farrell MA, Patz EF. Pulmonary nontuberculous mycobacterial infection: radiologic manifestations. RadioGraphics 1999;19:1487-1503
  2. McLoud TC, Boiselle PM. Thoracic Radiology: The Requisites, Second Edition. Mosby Elsevier, Philadelphia 2010
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Additional Details:

Case Number: 61899562Last Updated: 2012-09-08
Anatomy: Chest   Pathology: Infection
Modality: CTAccess Level: Readable by all users

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