Yonsei Med J.  2010 Jul;51(4):546-551. 10.3349/ymj.2010.51.4.546.

Consolidations in Nodular Bronchiectatic Mycobacterium Avium Complex Lung Disease: Mycobacterium Avium Complex or Other Infection?

• Im SA
• Park HJ
• Park SH
• Chun HJ
• Jung WS
• Kim SH

• KMID: 1805192
• DOI: http://doi.org/10.3349/ymj.2010.51.4.546

Abstract

PURPOSE
The objective of this study is to define the clinical implications of consolidations in nodular bronchiectatic type Mycobacterium avium complex (NB-MAC) infection.
MATERIALS AND METHODS
A total of 69 patients (M : F = 17 : 52; mean age, 64 years; age range, 41-85 years) with MAC isolated in the sputum culture and nodular bronchiectasis on the initial and follow-up CT scans were included. We retrospectively reviewed the incidence of consolidation and analyzed its clinical course by using radiographic changes with or without anti-MAC drug therapy.
RESULTS
In 44 of the 69 cases (64%), focal consolidations were seen on the initial and follow-up CT images. In 35 of the 44 (80%) cases, consolidations completely regressed, and in 3 cases (7%), consolidations partially regressed within 2 months with only antibiotics. In 2 cases (5%), the consolidations remained stable for over 2 months without anti-MAC drug therapy. Only in 4 cases (9%) did the consolidations improve after anti-MAC drug therapy. In 11 of the 38 cases (29%) with responsiveness to antibiotics, non-mycobacterial micro-organisms were identified in sputum, including pseudomonas, hemophilus, staphylococcus, and others.
CONCLUSION
In NB-MAC, consolidations are commonly present on CT. In these conditions, most of consolidations result from pneumonia other than MAC.

Keyword

Mycobacterium avium complex; lung; computed tomography

Figure

• 

  Fig. 1 A 45-year-old woman with NB-MAC, initially presenting with consolidation. (A) Plain chest radiography shows an ill-defined ovoid consolidation in left middle lung zone (arrow). (B) Initial CT scans shows mild cylindrical bronchiectasis and adjacent centrilobular nodules in right middle lobe and lingula, suggestive of NB-MAC. A focal consolidation is seen in subpleural region of lingula (double arrows). (C) FU plain radiography after 2 weeks shows disappearance of the prior focal consolidation after antibiotic therapy. NB-MAC, nodular bronchiectatic type Mycobacterium avium complex; FU, follow-up.

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  Fig. 2 A 48-year-old man with NB-MAC, who had a consolidation without response to antibiotics. (A and B) Initial CT shows multifocal clusters of centrilobular nodules with tree in bud appearance in right upper and middle lobes and lingula (arrowheads). Peripheral airways of right upper lobe are minimally dilated (thin arrow). A focal consolidation is seen at anterior subpleural region of lingula (arrow). (C) Two-month FU CT shows little change in size of the prior consolidation in lingula (double arrows) after empirical antibiotics. NB-MAC, nodular bronchiectatic type Mycobacterium avium complex; FU, follow-up.

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  Fig. 3 A 53-year-old women with NB-MAC, who had newly detected consolidations during FU period managed with empirical antibiotic therapy. (A) Initial CT shows bronchiectasis with atelectasis and nearby clustered micronodules in right middle lobe. Faint nodular opacities are also visible at posterior aspect of right lower lobe (arrowheads). (B) Six-month FU HRCT at the same level to A shows a new irregular consolidation at posterior subpleural region of right lower lobe (arrow). Another smaller consolidation is seen in right middle lobe (double arrows). Bronchiectasis and clustered centrilobular nodules of right middle lobe, indicative of NB-MAC, are more clearly demarcated than before. The pre-existing faint nodules of right lower lobe are invisible, suggestive of improvement of focal bronchiolitis. (C) One-month FU HRCT after antibiotic therapy shows complete regression of the prior consolidations in right middle and lower lobes. NB-MAC, nodular bronchiectatic type Mycobacterium avium complex; FU, follow-up; HRCT, high-resolution CT.

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  Fig. 4 A 72-year-old man with NB-MAC, who had newly detected consolidations during FU with response to anti-MAC therapy. (A) Axial CT shows multifocal cylindrical bronchiectasis and centrilobular nodules with volume loss in both lungs. Irregular consolidations are seen at posterior aspect of right lower lobe (arrow). Anti-MAC therapy was initiated. (B) Plain radiograph obtained at the same day to A shows multifocal consolidations and small nodular opacities in right lung and left lower lung zone. (C) FU plain radiography after 2 months shows decreased extent of the consolidations and nodules of both lungs. NB-MAC, nodular bronchiectatic type Mycobacterium avium complex; FU, follow-up.

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