[MYCOBACTERIUM ABSCESSUS PULMONARY DISEASE: IMPORTANT PATHOGEN INVOLVED IN MICROBIAL SUBSTITUTION DURING THE TREATMENT OF NON-ABSCESSUS MYCOBACTERIAL DISEASE].

INTRODUCTION: Mycobacterium abscessus pulmonary disease is common in patients with bronchiectasis. However, the underlying disease that is more likely to be present in patients with M. abscessus pulmonary disease remains poorly understood. METHOD: From 2001 through 2010, all patients, whose sputum or bronchoscopic lavage cultures yielded M. abscessus, were included in the study. RESULTS: Among the 11 patients included (male/female: 4/7), 4 male patients had a history of smoking. All 11 patients presented with bronchiectasis on computed tomography before the detection of M. abscessus, and most patients demonstrated nodular bronchiectasis on chest computed tomography. Six patients (54.5%) developed M. abscessus pulmonary disease during treatment for non-abscessus non-tuberculous mycobacterial disease: M. avium complex pulmonary disease in 5 and M. kansasii infection in 1. Although laboratory examination yielded negative findings for non-abscessus mycobacterium when M. abscessus was detected, radiographic deterioration was observed in 4 of 6 patients. Five patients received drug therapy, 3 of whom were treated with multi-drug therapy including clarithromycin, ethambutol, and rifampicin, and the remaining 2 patients received low-dose macrolide therapy. However, M. abscessus was detected consistently in all patients, and deteriorated chest CT findings were observed in 4. Among the remaining 6 patients untreated with drugs, sputum cultures yielded. M. abscessus with radiographic deterioration in 4 patients. CONCLUSION: Our results indicated that M. abscessus infection developed during the treatment for non-abscessus mycobacterial disease, which was mainly due to M. avium complex pulmonary disease in most patients. M. abscessus infection thus occurred via microbial substitution. This phenomenon should be considered an important issue during the treatment for non-abscessus mycobacterial disease, which requires long-term medication.

Benign myoepithelioma in the intrathoracic trachea.

A 67-year-old woman who was followed as a patient with bronchial asthma for 1.5 years visited our hospital with progressive dyspnea. Although the chest radiography findings were normal, a chest computed tomography scan revealed a mass obliterating the intrathoracic tracheal lumen. The patient's symptoms disappeared immediately after tumor excision, and no recurrence was observed during a 1.5-year follow-up period. Microscopically, the tumor was composed of densely packed polygonal-, oval- and spindle-shaped cells that were positive for pan-cytokeratin, α-smooth muscle actin and p63. These pathological findings confirmed the diagnosis of benign myoepithelioma. Chest physicians should recognize that benign myoepithelioma can develop in the trachea, although it is very rare.

Two cases of tuberculosis with multiple drug hypersensitivity after drug-induced hypersensitivity syndrome.

Here, we report 2 cases of drug-induced hypersensitivity syndrome (DIHS) caused by salazosulfapyridine and allopurinol during tuberculosis treatment. Both patients also developed multiple drug hypersensitivity (MDH) to several antituberculosis drugs that were used at around the period of DIHS onset, and thus, the treatment could not be successfully completed. Our cases show that MDH can easily occur after development of DIHS. Considering that treatment for tuberculosis requires long-term management with several drugs, it is important to refrain from administering drugs that can cause DIHS during tuberculosis treatment.