Solitary pulmonary nodules due to non-tuberculous mycobacteriosis among 28 resected cases

Prevalence of Mycobacterium kansasii in clinical and environmental isolates, a systematic review and meta-analysis

Background

Mycobacterium kansasii infection is one of the most common causes of non-tuberculosis mycobacterial (NTM) disease worldwide. However, accurate information on the global prevalence of this bacterium is lacking. Therefore, this study was conducted to investigate the prevalence of M. kansasii in clinical and environmental isolates.

Methods

Databases, including PubMed, Scopus, and the Web of Science, were utilized to gather articles on the prevalence of M. kansasii in clinical and environmental isolates. The collected data were analyzed using Comprehensive Meta-Analysis software.

Results

A total of 118 and 16 studies met the inclusion criteria and were used to analyze the prevalence of M. kansasii in clinical and environmental isolates, respectively. The prevalence of M. kansasii in NTM and environmental isolates were 9.4 and 5.8%, respectively. Subsequent analysis showed an increasing prevalence of M. kansasii over the years. Additionally, the results indicated a significant difference in the prevalence of this bacteria among different regions.

Conclusion

The relatively high prevalence of M. kansasii among NTM isolates suggests the need for further implementation of infection control strategies. It is also important to establish appropriate diagnostic criteria and management guidelines for screening this microorganism in environmental samples in order to prevent its spread, given its high prevalence in environmental isolates.

Lobectomy for Suspected Lung Cancer Without Prior Diagnosis

BACKGROUND

We describe use, patients, and outcome of diagnostic lobectomy for suspected lung cancer without pathologic confirmation.

METHODS

A retrospective review of consecutive lobectomy or bilobectomy for suspected or confirmed primary pulmonary malignancy was conducted using our participant's sample of The Society of Thoracic Surgeons database. Surgeons performed lobectomy based on clinical diagnosis or confirmation on a biopsy specimen. Lung cancer confirmed by biopsy specimen was compared with cases clinically suspected. Univariate and multivariate analyses identified variables associated with lobectomy without biopsy specimen confirmation.

RESULTS

Among 2651 lobectomies performed between 2006 and 2019 in 2617 patients, lung cancer was confirmed by preoperative biopsy specimen in 51.6% (1368 of 2651) or was clinically suspected before the operation in 48.4% (1283 of 2651). The intraoperative biopsy specimen in 585 of 1283 cases (45.6%) proved lung cancer before lobectomy, whereas lobectomy proceeded in 698 cases (54.4%) without a diagnosis. Final pathology proved lung cancer in 90% (628 of 698) without a diagnosis before lobectomy and nonmalignant disease in 10% (70 of 698). Nonneoplastic pathology included granulomas (30 of 70 [43%]), pneumonia (12 of 70 [17%]), bronchiectasis (7 of 70 [10%]), and other lesions (21 of 70 [30%]). Operative mortality was 0.94% (25 of 2651) for the cohort and 1.0% (7 of 698) for diagnostic lobectomy only. Multivariate analysis identified patient age, type of lobectomy (right middle lobe), and the intermediate study tercile as associated with diagnostic lobectomy.

CONCLUSIONS

Lobectomy for suspected lung cancer without diagnosis is common, represents practice variation, and infrequently (10% diagnostic, 2.6% all lobectomies) removes nonmalignant disease. Tissue confirmation before lobectomy is preferred, particularly when operative risk is increased. Diagnostic lobectomy is acceptable in carefully selected patients and lesions.

Impact of lung cancer surgery on comorbid Mycobacterium avium complex lung disease-A case series

The number of cases with Mycobacterium avium and Mycobacterium intracellulare lung diseases (Mycobacterium avium complex lung disease [MACLD]) are increasing globally. Lung cancer can sometimes present as a comorbidity with MACLD; however, the clinical presentation and outcomes of comorbid MACLD following lung cancer resection remain unclear. Therefore, we retrospectively assessed 17 patients with MACLD undergoing lung cancer resection to determine the impact of lung cancer surgery on comorbid MACLD. Of the 17 patients, Mycobacterium avium and Mycobacterium intracellulare were present in 15 and 2 patients, respectively; 14 patients had stage I lung cancer and underwent lobectomy. Ten patients were postoperatively observed for MACLD without any further intervention, five patients underwent additional resection for conspicuous MACLD lesions, and the remaining two patients underwent complete resection for MACLD and lung cancer within the same lobe followed by rifampicin, ethambutol, and clarithromycin (RECAM) therapy. Seven patients exhibited postoperative MACLD exacerbation, six of whom developed exacerbation in the operated ipsilateral residual lobes. Six of these seven patients received RECAM, three of whom (43%) subsequently exhibited improvement. Attention should be paid to MACLD exacerbation during postoperative follow-up, especially in ipsilateral lobes. Although RECAM therapy may be beneficial in alleviating MACLD exacerbation, further investigation is warranted to validate these results.

Varying clinical presentations of nontuberculous mycobacterial disease : Similar to but different from tuberculosis

The incidence rate of pulmonary nontuberculous mycobacterial disease (PNTMD) in Japan is the highest among major industrialized nations. Although the typical clinical course and radiological manifestations of PNTMD are different from those of pulmonary tuberculosis (TB), confusion about these mycobacterial diseases leads to a diagnostic pitfall. Diagnostic challenges include the coexistence of Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM), false positives for NTM in MTB nucleic acid amplification tests, microbial substitution, and abnormal radiological manifestations caused by NTM. Features of extrapulmonary NTM diseases, such as pleurisy, vertebral osteomyelitis, and disseminated disease, are different from the corresponding tuberculous diseases. Moreover, the immunological background of the patient (status of human immunodeficiency virus infection with or without antiviral therapy, continuation or discontinuation of immunosuppressive therapy, use of immune checkpoint inhibitor, pregnancy and delivery, etc.) influences the pathophysiology of mycobacterial diseases. This review describes the varying clinical presentations of NTM disease with emphasis on the differences from TB. J. Med. Invest. 68 : 220-227, August, 2021.

A solitary pulmonary nodule caused by Mycobacterium avium with pleural effusion and pleuritis after transbronchial biopsy: a case report

BACKGROUND

Pleural effusion and pleuritis are uncommon manifestations of Mycobacterium avium complex pulmonary disease. Pleuritis caused by Mycobacterium avium complex pulmonary disease presenting as a solitary pulmonary nodule is extremely rare. The pathogenesis of Mycobacterium avium complex pleuritis has not been elucidated. However, it has been suggested that secondary spontaneous pneumothorax from Mycobacterium avium complex pulmonary disease is one of the causes of Mycobacterium avium complex pleuritis.

CASE PRESENTATION

A 67-year-old Japanese woman who presented with a solitary pulmonary nodule developed a transient pneumothorax after transbronchial biopsy. A definitive diagnosis of solitary pulmonary nodule could not be made on bronchoscopy, so video-assisted thoracoscopic surgery was performed 1 month after bronchoscopy. On the day of hospitalization for the procedure, a left-sided pleural effusion appeared on a chest radiograph. Thickening of the parietal and visceral pleura and numerous scattered white small granules were seen on thoracoscopy. Histologic examination of the resected left lower lobe and a biopsy of the parietal pleura showed Mycobacterium avium complex solitary pulmonary nodule and Mycobacterium avium complex pleuritis.

CONCLUSION

Iatrogenic pneumothorax can be a cause of pleuritis in a patient with Mycobacterium avium complex pulmonary disease. Clinicians should watch for the appearance of secondary pleuritis after transbronchial biopsy even in a patient with localized disease such as Mycobacterium avium complex solitary pulmonary nodule.

Analysis of pulmonary nodules caused by nontuberculous mycobacteriosis in 101 resected cases: multi-center retrospective study

Background

Solitary pulmonary nodules caused by nontuberculous mycobacteriosis are included as a category of pulmonary nontuberculous mycobacterium disease. Clinical characteristics, treatments and prognosis are not fully known because there are a few related reports.

Methods

This was a multi-center retrospective study of 101 cases diagnosed as solitary nodular type of nontuberculous mycobacteriosis from January 2000 to March 2017 that underwent resection at 9 related facilities belonging to the Thoracic Surgery Study Group of Osaka.

Results

The most common pathogen was Mycobacterium avium complex (n=77, 87.5%), followed by Mycobacterium kansasii (n=8, 9.1%). Chest computed tomography results showed subpleural locations that were difficult to distinguish from lung cancer. Fluorodeoxyglucose positron emission tomography/computed tomography was performed in 58 cases and positive results were obtained in 35 (60.3%), with an average maximum standardized uptake value of 3.87. The purpose of resection in most cases was for diagnosis. The surgical procedure was wedge resection in 87, segmentectomy in 3, and lobectomy in 11, while 77 underwent thoracoscopic surgery. Postoperative complications occurred in 7 cases, though no infections caused by nontuberculous mycobacteriosis were noted. The median observation period was 27 months. A worsened condition occurred in 10 (9.9%) with Mycobacterium avium complex, though none had local recurrence.

Conclusions

Solitary pulmonary nodules due to nontuberculous mycobacteriosis is difficult to diagnose based on preoperative examination results or distinguish from lung cancer. Among the present cases, none had local complications or recurrence, even in those that underwent a wedge resection, thus postoperative chemotherapy was not considered necessary if a complete resection was performed. On the other hand, some cases showed reinfection after a long period following resection, thus patients should be informed of that future possibility.

Application of diagnostic criteria for non-tuberculous mycobacterial disease to a case series of mycobacterial-positive isolates

The American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA) have provided guidelines to assist in the accurate diagnosis of lung disease caused by nontuberculous mycobacteria (NTM). These microbiologic, radiographic, and clinical criteria are considered equally important and all must be met to make the diagnosis of NTM lung disease. To assess the significance of the three criteria, each was evaluated for its contribution to the diagnosis of NTM lung disease in a case series. Laboratory reports of any specimen positive for NTM isolation were collected between January 1, 2006 and December 31, 2010 at a university medical center. Medical records were reviewed in detail using a standardized form. The total number of patients with a culture from any site positive for NTM was 297 while the number from respiratory specimens during the same period was 232 (78%). Samples from two of these patients also yielded M. tuberculosis complex and were excluded. While 128 of the remaining 230 patients (55.7%) in the cohort met the microbiologic criterion for diagnosis of NTM lung disease, 151 (65.6%) and 189 (78.3%) met the radiologic and clinical criteria respectively. Only 78 patients (33.9%) met all three criteria provided by the ATS/IDSA for diagnosis of NTM lung disease. This evaluation reaffirms that defining NTM lung disease using either one or two of the criteria provided by the 2007 ATS/IDSA guidelines may significantly overestimate the number of cases of NTM lung disease. Based on the experience of defining NTM lung disease in this case series, recommendations for modification of the ATS/IDSA guidelines are provided which include expansion of both radiologic patterns and the list of symptoms associated with NTM lung disease.

Clinical Characteristics and Outcomes of Surgically Resected Solitary Pulmonary Nodules Due to Nontuberculous Mycobacterial Infections

Background: Limited data are available regarding the detailed characteristics and outcomes of surgically resected nontuberculous mycobacterial (NTM) granulomas. Methods: We evaluated the characteristics of 49 NTM granulomas presenting as solitary pulmonary nodules (SPNs) between January 2007 and December 2016. Results: Twenty-five patients (51%) were male and 27 (55%) were never-smokers. Seven (14%) patients had a history of tuberculosis. More than half (51%) of patients were asymptomatic. On chest computed tomography, the median SPN diameter was 18 mm, and approximately half of all SPNs (49%) were located in the upper lobes on chest computed tomography. NTM strain were preoperatively isolated from sputum (46%, 12/26), bronchial wash fluid (54%, 14/26), and needle biopsy specimens (12%, 3/26). Mycobacterium avium (71%, 22/31) was the organism most commonly isolated, followed by Mycobacterium intracellulare (16%, 5/31). Postoperative pneumothorax and atelectasis developed in four (8%) patients and one (2%) patient, respectively. Five patients received postoperative antibiotic therapy. Over a median follow-up period of 18.0 months, one patient with residual lesions after surgery started macrolide-based therapy due to aggravated symptoms. Conclusions: Most NTM granulomas can be treated completely by surgical resection without antibiotic therapy, and microbiological examination of surgical specimens is important for optimal management.

Surgical resection is sufficient for incidentally discovered solitary pulmonary nodule caused by nontuberculous mycobacteria in asymptomatic patients

Incidentally discovered solitary pulmonary nodules (SPN) caused by nontuberculous mycobacteria (NTM) is uncommon, and its optimal treatment strategy remains uncertain. This cohort study determined the clinical characteristics and outcome of asymptomatic patients with NTM-SPN after surgical resection. Resected SPNs with culture-positive for NTM in six hospitals in Taiwan during January, 2010 to January, 2017 were identified. Asymptomatic patients without a history of NTM-pulmonary disease (PD) or same NTM species isolated from the respiratory samples were selected. All were followed until May 1, 2019. A total of 43 patients with NTM-SPN were enrolled. Mycobacterium avium complex (60%) and M. kansasii (19%) were the most common species. The mean age was 61.7 ± 13.4. Of them, 60% were female and 4% had history of pulmonary tuberculosis. The NTM-SPN was removed by wedge resection in 38 (88%), lobectomy in 3 (7%) and segmentectomy in 2 (5%). Caseating granuloma was the most common histologic feature (58%), while chronic inflammation accounts for 23%. Mean duration of the follow-up was 5.2 ± 2.8 years (median: 4.2 years [2.5–7.0]), there were no mycobacteriology recurrence or NTM-PD development. In conclusion, surgical resection is likely to curative for incidentally discovered NTM-SPN in asymptomatic patients without culture evidence of the same NTM species from respiratory specimens, and routine mycobacterium culture for resected SPN might be necessary for differentiating pulmonary tuberculosis and NTM because further treatment differs.

Solitary pulmonary nodules caused by Mycobacterium avium complex

BACKGROUND

The prevalence of Mycobacterium avium complex (MAC) pulmonary disease (PD) is increasing significantly in Japan. Among the patterns of MAC-PD, a solitary pulmonary nodule (SPN) is less common and often resembles lung cancer. The aim of this study was to identify the clinical features of MAC-SPN.

METHODS

SPNs culture-positive for MAC (definite cases) and culture-negative SPNs showing nucleic acid amplification test (NAAT)-positive status (probable cases) that presented between January 2007 and December 2017 were enrolled. The patients' clinical, laboratory, radiological, and microbiological findings and outcomes were investigated.

RESULTS

This study included 28 patients (median age, 66 years; 16 men, 12 women). All patients were asymptomatic when the disease was detected. Median SPN size was 23.5 mm. Twenty-six patients underwent video-assisted thoracoscopic surgery, while the others underwent percutaneous needle biopsy for diagnosis. Granulomatous inflammation was confirmed in all cases. Microbiologically, the 28 cases were divided into 17 in the definite group and 11 in the probable group. In both groups, M. avium was predominant. There were no significant differences in clinical and radiological findings and follow-up periods between the 2 groups. After diagnosis, 6 patients received medical treatment, while the others did not. The median follow-up period was 42 months, and no recurrence was observed in both groups.

CONCLUSIONS

MAC should be considered in the differential diagnosis of SPNs in asymptomatic patients. To overcome the difficulties in diagnosing MAC-SPN, this study underscores the importance of diagnostic interventions and identification of MAC by culture and/or NAAT in biopsied specimens.