Yield of computed tomography and bronchoscopy for the diagnosis of Mycobacterium avium complex pulmonary disease.

Abstract

Mycobacterium avium complex (MAC) pulmonary disease with nodules and bronchiectasis is increasing. But the usefulness of computed tomography (CT) and bronchoscopy for diagnosis and the significance of MAC isolation from respiratory secretions are still unclear. For a 4-yr period, we prospectively examined the role of bronchoscopy with bronchial washing and transbronchial lung biopsy in 26 patients who had clusters of small nodules in the periphery of the lung associated with ectatic changes of the draining bronchi on the CT scan. None of them was infected with human immunodeficiency virus. Thirteen of the 26 patients (50%) had cultures positive for MAC, six in the sputum and 13 in the bronchial washing. Epithelioid granuloma was demonstrated in eight of 13 patients with culture-positive MAC and in two of 13 patients in whom MAC was culture-negative. Rapidly growing mycobacteria were cultured in the two patients. Seven of the eight biopsy-positive patients received treatment and responded by sputum conversion and/or radiographic improvement. We found that the CT finding was a useful clue to suspect MAC pulmonary disease and that the bronchial washing was more sensitive than the routine expectorated sputum for MAC isolation. Demonstration of granuloma in more than half of the MAC-positive patients would suggest that MAC may have invaded the lung tissue rather than colonized in the airways.

Polypoid bronchial lesions due to Scedosporium apiospermum in a patient with Mycobacterium avium complex pulmonary disease

“…Recently, the disease has become prevalent in elderly females without predisposing bronchopulmonary illness. Characteristic CT findings of MAC pulmonary disease are clusters of small nodules in the subpleural regions of the lung in combination with dilated changes of the bronchi [6]. Between 1990 and 1997, 210 patients with MAC pulmonary disease were seen in the author's hospital and a variety of fungi were concurrently isolated from 10 patients: Aspergillus fumigatus (6), Aspergillus niger (2), S. apiospermum (2), Schizophyllum commune (1) and Exophiala dermatitidis (1) (unpublished data).…”

Bronchoscopy in Bronchiectasis and Cystic Fibrosis

“…As mentioned earlier, in patients with bronchiectasis with suggestion of MAC on HRCT Tanaka et al found that 10/26 who underwent transbronchial lung biopsy had granuloma formation, 8 of whom were positive for MAC and 2 were positive for M. abscessus and M. fortuitum. They showed that this was present with infection and not with colonization (Tanaka, E. 1997).…”

“…They also found comparable sensitivities between both BAL and protected specimen brush. Tanaka et al found that bronchial washings was twice as sensitive as expectorated sputum for isolation of Mycobacterium avium complex (Tanaka, E. 1997). They also went on to show that granuloma formation as seen on lung biopsy would suggest infection rather than colonization.…”

Lady Windermere syndrome

“…16 Studies show that in patients with MAC pulmonary disease, cultures from bronchial lavages have a greater sensitivity than sputum cultures; positive cultures were present in 93.8% and 50% of bronchial washings compared to 64.3% and 23.1% of sputum samples, respectively. 74,75 In suspected cases of LWS with three negative sputum samples, bronchoscopy with bronchial washings may be needed to confirm the diagnosis. Recently, polymerase chain reaction (PCR) and serodiagnostic tests have been utilized for rapid diagnosis.…”