High recurrence rate of lymphadenitis due to nontuberculous mycobacteria and its association with concurrent Salmonella infection in Taiwan

Granulomatous lymphadenitis in Taiwan: Unraveling infantile peak and Bacillus Calmette-Guérin lymphadenitis

BACKGROUND

Granulomatous lymphadenitis, a histopathological diagnosis, often indicates infections, such as those caused by mycobacterial and fungal agents.

METHODS

We conducted an analysis of 1098 granulomatous lymphadenitis cases, examining age distribution, lymph node locations, and laterality. Molecular detection of Bacillus Calmette-Guérin (BCG) was performed on archived formalin-fixed paraffin-embedded tissue specimens.

RESULTS

Our analysis revealed a bimodal age distribution, notably with a minor peak in infants. These infantile cases predominantly featured axillary involvement, frequently occurring on the left side. Positive rates of BCG identification decreased with age: <1 year, 71%; 1-2 year, 33%; 2-3 year, 13%; 3-4 year, 0%. Remarkably, only one of the 14 cases with molecularly confirmed BCG lymphadenitis had comments regarding BCG in the pathological report. Compared with patients born after 2016 (BCG at 5-8 months), those born before 2016 (BCG at birth) developed BCG lymphadenitis at a wider age range with right skewness (before 2016, 13 ± 11 months [range, 3-33 months] vs. after 2016, 10 ± 2 months [range, 8-13 months]). Four of the 14 BCG-positive cases had congenital heart disease. Seven patients received anti-tuberculosis drugs following surgical excision. No surgical complications were reported.

CONCLUSIONS

BCG lymphadenitis constitutes a distinctive minor peak within the spectrum of granulomatous lymphadenitis in Taiwan. Pathologists should consider the possibility of BCG infection, especially in cases of infantile axillary, supraclavicular, neck lymphadenopathies on the left side. Moreover, BCG administration at 5-8 months may reduce delayed-onset BCG lymphadenitis.

Mycobacterium xenopi infection of the kidney and lymph nodes: A case report

The incidence of nontuberculous mycobacterial (NTM) infection has been increasing globally. Further, it has been reported that early NTM infection diagnosis and treatment can considerably improve patient prognosis. However, traditional methods for detecting pathogenic microorganisms are associated with several limitations, and optimal treatment regimens for several NTM infections have not yet been established. Here, we report the case of a 22-year-old woman with renal and lymph node Mycobacterium xenopi infection. This patient presented with repeated fever and systemic lymphadenopathy events for more than 2 years, but the etiology of the disease was unclear. We performed metagenomic next-generation sequencing (mNGS) using tissue sections from the patient's left kidney and successfully identified M. xenopi. Thereafter, the patient's condition was effectively controlled via treatment with rifampicin, clarithromycin, and ethambutol hydrochloride (orally administered after hemodialysis). Further, this case showed that the clinical symptoms of NTM infection are atypical and highly occult, especially for extrapulmonary NTM infections, which are difficult to diagnose. Therefore, mNGS may be a powerful tool for diagnosing NTM infections. The combination therapy used showed efficacy and thus could serve as a reference treatment for kidney and lymph node M. xenopi infection.

Ethambutol-resistant Mycobacterium kansasii cervical lymphadenitis in an immunocompetent adult patient: A case report and literature review

Mycobacterium kansasii extrapulmonary infections are infrequent in immunocompetent adults. Rifampin (RIF), clarithromycin (CLR), isoniazid (INH) and ethambutol (EMB) are included in all the standard regimens against M.kansasii. We report a case of a healthy 65-year-old male farmer who presented with isolated right supraclavicular lymphadenopathy. The lymph node FNA showed acid-fast-bacilli and granulomatous inflammation. Quantiferon TB Gold test, HIV serology, and functional immunological studies were all negative or normal. He was put on a standard 4 drugs anti-tuberculous regimen that was switched to RIF + CLR+ INH after the Microbiology lab demonstrated an EMB–resistant Mycobacterium kansasii isotype I strain. The patient was cured after 12 months of therapy. This is the 6th reported case of M. kansasii extrapulmonary lymphadenitis in an immunocompetent adult and the 2nd showing EMB resistance in the world literature. Antimycobacterial regimens against M. kansasii, classically resistant to pyrazinamide (PZA) might also exclude EMB due to its increasing resistance in Europe. A 612 months therapy with at least 2 effective antimycobacterial drugs including RIF + CLR might be enough to treat extrapulmonary M. kansasii infections in immunocompetents.

A rare case of lymphadenitis and pulmonary disease caused by Mycobacterium paraffinicum

With over 150 species, non-tuberculous mycobacteria are increasingly recognized to be important human pathogens that pose diagnostic and management challenges. We report a rare case of cervical lymphadenitis and pulmonary disease caused by Mycobacterium paraffinicum in a 64-year-old man who presented with three-month history of increasing right-sided painless neck lump. His medical history included rheumatoid arthritis, which was managed with leflunomide and methotrexate. Computed tomography scans of his neck and thorax revealed a right lower neck and supraclavicular fossa cystic mass with peripheral enhancement and bilateral multiple small pulmonary nodules. M. paraffinicum was cultured from a fine-needle aspiration of the mass. Two out of three sputa were acid-fast bacilli smear positive but cultures did not yield any viable organism. He developed spontaneous discharge of purulent material via a sinus, which drained over two months and recovered with a completely healed sinus without any further treatment.

Risk factors for microbiologic failure among Taiwanese adults with Mycobacterium abscessus complex pulmonary disease

BACKGROUND

The Mycobacterium abscessus complex is a common cause of pulmonary nontuberculous mycobacteria infections in Taiwan. We examined the risk factors associated with treatment outcome in Taiwanese adults with pulmonary disease caused by the M. abscessus complex.

METHODS

We retrospectively reviewed the records of all patients from a southern Taiwan medical center from 2006 to 2012 who had respiratory specimens identified as M. abscessus complex and met the American Thoracic Society criteria for pulmonary disease.

RESULTS

Of the 106 included patients, females (58.5%) and nonsmokers (79.2%) predominated. The mean age of patients was 64.8 years. Sixty-three patients (59.4%) had pre-existing lung disease. Previous mycobacterial pulmonary disease (34.9%) was the most common underlying disorder. Chest radiography indicated that bronchiectasis was common (47.2%) and that cavitations were less common (14.2%). Fifty-six patients received antibiotic treatment. Clinicians were more likely to prescribe antibiotics if the initial sputum acid-fast staining was positive (p < 0.001). Treatment outcome was analyzed in 26 patients who were treated for more than 3 months; three of these patients (11.5%) had clinical failure and 18 (69.2%) experienced sputum conversion. Patients with cavitary lesions were more likely to experience microbiologic failure (p = 0.02). Nine patients had positive cultures after antibiotic treatment for > 1 year. Previous mycobacterial pulmonary disease (p = 0.011) and cavitary lesion (p = 0.034) are risk factors for persistence of M. abscessus complex.

CONCLUSION

With antimicrobial therapy, previous mycobacterial disease, and cavitary lesion are associated with microbiologic failure in Taiwanese adults with M. abscessus complex pulmonary disease.