Radiographic findings in patients with acquired immunodeficiency syndrome, pulmonary infection, and microbiologic evidence of Mycobacterium xenopi

Miliary pulmonary nodules due to Mycobacterium xenopi in a steroid-induced immunocompromised patient successfully treated with chemotherapy: a case report

Background

Mycobacterium xenopi-infected patients have a high prevalence of pulmonary cavities and nodules. However, the clinical course for patients with miliary nodules due to M. xenopi has not yet been reported.

Case presentation

We encountered a case of miliary nodules with gradually worsening coughing and sputum production in a 44-year-old male who had renal dysfunction due to glomerulosclerosis with a decade-long history of steroid therapy. Although we started anti-tuberculosis treatment on clinical suspicion of miliary tuberculosis, cultures of sputum and bronchial lavage were both positive for M. xenopi. The patient was successfully treated with rifampin, ethambutol and clarithromycin, without fibrosis. It was unclear whether the miliary pattern was induced by hematogenous or endobronchial spread of the M. xenopi infection.

Conclusion

Even when clinical and radiological disease manifestations are similar to those of miliary tuberculosis, M. xenopi infection should be considered in the differential diagnosis of miliary nodules.

Nontuberculous mycobacterial pulmonary infection in patients with idiopathic interstitial pneumonias: comparison with patients without idiopathic interstitial pneumonias

OBJECTIVE

The aim of this study was to describe computed tomography (CT) findings of nontuberculous mycobacterial (NTM) pulmonary infection in patients with idiopathic interstitial pneumonias (IIP) in comparison with those in patients without IIP.

METHODS

From November 2001 to October 2012, 810 patients in the NTM registry were retrospectively reviewed. Among them, 42 patients (mean age, 69.7 years; 32 men and 10 women) who were diagnosed as having IIP by either histological or radioclinical criteria were included in our study. Eighty-two age- and sex-matched immunocompetent patients with NTM pulmonary infection and without IIP were selected as the control group. Medical records and CT scans were reviewed. Formal radiologic reports obtained before diagnosis of NTM infection were also reviewed.

RESULTS

Lobar/segmental consolidation (85.7%) was the most common CT finding in the IIP group, whereas branching centrilobular nodules (95.1%), traction bronchiectasis (79.3%), and volume decrease (58.5%) were common in the control group. Frequencies of these findings were significantly different between the 2 groups (P < 0.001). Most of consolidations were associated with cavity (83.3%) without dominant zonal distribution. Pneumonia or fungal infection (n = 20) was the most common radiologic diagnosis in the IIP group.

CONCLUSIONS

The NTM pulmonary infection in IIP patients is characterized as lobar/segmental consolidation with/without cavity, different to immunocompetent patients without IIP, and can mimic other diseases especially bacterial/fungal infection.

Comparative radiological features of disseminated disease due to Mycobacterium tuberculosis vs non-tuberculosis mycobacteria among AIDS patients in Brazil

Background

Disseminated mycobacterial disease is an important cause of morbidity and mortality in patients with HIV-infection. Nonspecific clinical presentation makes the diagnosis difficult and sometimes neglected.

Methods

We conducted a retrospective cohort study to compare the presentation of disseminated Mycobacterial tuberculosis (MTB) and non-tuberculous Mycobacterial (NTM) disease in HIV-positive patients from 1996 to 2006 in Brazil.

Results

Tuberculosis (TB) was diagnosed in 65 patients (67.7%) and NTM in 31 (32.3%) patients. Patients with NTM had lower CD4 T cells counts (median 13.0 cells/mm³ versus 42.0 cells/mm³, P = 0.002). Patients with tuberculosis had significantly more positive acid-fast smears (48.0% vs 13.6%, P = 0.01). On chest X-ray, miliary infiltrate was only seen in patients with MTB (28.1% vs. 0.0%, P = 0.01). Pleural effusion was more common in patients with MTB (45.6% vs. 13.0%, P = 0.01). Abdominal adenopathy (73.1% vs. 33.3%, P = 0.003) and splenic hypoechoic nodules (38.5% vs. 0.0%, P = 0.002) were more common in patients with TB.

Conclusion

Miliary pulmonary pattern on X-ray, pleural effusion, abdominal adenopathy, and splenic hypoechoic nodules were imaging findings associated with the diagnosis of tuberculosis in HIV-infected patients. Recognition of these imaging features will help to distinguish TB from NTM in AIDS patients with fever of unknown origin due to disseminated mycobacterial disease.

The Many Faces of Pulmonary Nontuberculous Mycobacterial Infection

OBJECTIVE

The purpose of this article is to review clinical and radiologic manifestations of pulmonary nontuberculous mycobacterial infection.

CONCLUSION

Common and well-recognized patterns of infection include cavitary and bronchiectatic disease and infection in AIDS patients. Less common or well-recognized manifestations include nodules or masses mimicking malignancy, hypersensitivity pneumonitis, and others. Definitive diagnosis can be difficult and patterns may overlap. Timely diagnosis requires a high index of suspicion and knowledge of the spectrum of clinical and radiologic features.

Pulmonary resection for Mycobacterium xenopi pulmonary infection

BACKGROUND

Results of medical therapy for Mycobacterium xenopi pulmonary infection remain unreliable. Pulmonary resection may be beneficial to patients whose disease is localized and who can tolerate a resectional operation.

METHODS

Eighteen patients underwent pulmonary resection between 1991 and 2000: 14 men and 4 women, with a mean age of 50 +/- 12 years (range 27 to 68 years). Indications for operation were either therapeutic (n = 9) or diagnostic (n = 9). Four patients received antimycobacterial chemotherapy before their operation and 2 patients were HIV positive.

RESULTS

Therapeutic procedures included completion pneumonectomy (n = 1), lobectomy (n = 6), segmentectomy (n = 1), and bilateral wedge resection (n = 1). Diagnostic procedures included lobectomy (n = 1) and wedge resection (n = 8). Complete resection could be achieved in 15 patients (83%). There was no in-hospital mortality. Postoperative complications included prolonged air leak (5 of 18 patients, 27.7%) and pleural effusion requiring insertion of a new chest tube (3 of 18 patients, 16.6%). Mean hospital stay was 14 +/- 8 days. Follow-up was 100% complete. Eleven patients received antimycobacterial chemotherapy for 4 to 24 months, postoperatively. Late mortality was 11% and was unrelated to progression of mycobacterial disease. After the operation, the sputum remained positive in only 2 patients (11%) with incomplete resections. Fourteen patients were asymptomatic with no relapse at a mean follow-up of 38 +/- 22 months (range 85 to 13 months).

CONCLUSIONS

Resection represents an important adjunct to chemotherapy for the treatment of M. xenopi pulmonary disease. In the setting of localized nodular or cavitary disease, failure to respond to medical therapy, relapse after treatment discontinuation, coexistent aspergilloma or polymicrobial contamination, or patient intolerance of medical therapy, pulmonary resection can be undertaken with acceptable morbidity and mortality.