A Case of Mycobacterium kansasii Pulmonary Disease Presenting as Endobronchial Lesions in HIV-Infected Patient
A 39-year-old male presented with cough and blurred vision for 1 month. Six years ago he was diagnosed with HIV infection in another hospital and he was followed regularly at public health care facility. He had no previous history of pulmonary tuberculosis or other pulmonary diseases. He was a nonsmoker and nondrinker. Forty days ago before admission, he visited the other hospital due to blurred vision and cough for 1 month. CD4 cell counts were 3/mm3 and highly active antiretroviral therapy with combivir and kaletra was started with the concurrent treatment for cytomegalovirus retinitis. He was transferred to our hospital for further evaluation of chronic cough with an abnormal chest X-ray.\nThe patient had a chronically ill appearing and vital signs were stable. There were no specific findings in head and neck area. Breathing sounds were clear and there were no signs of abdominal tenderness. A complete blood count showed white blood cell count of 9,390/mm3 (neutrophil 61.0%, lymphocyte 21.0%, eosinophil 7.0%), hemoglobin 11.3 g/dL, and platelet 322×109/L with C-reactive protein of 3.62 mg/dL (normal, <0.5 mg/dL). A blood chemistry analysis was unremarkable. CD4 count was 247/mm3, and HIV viral load was 2,499 copies/mL. Tuberculin skin test revealed a negative result with a positive interferon-gamma release assay result. Initial chest X-ray showed bilateral hilar prominence, raising the possibility of bilateral hilar lymphadenopathy (). Chest computed tomography revealed multifocal nodular consolidations with some surrounding ground glass opacities in both lungs. There were several enlarged lymph nodes with some internal low-attenuated lesions in the paratracheal, subcarinal, and both hilar regions (). Bronchoscopy showed an elevated nodular lesion with central whitish necrosis at apical segment of right upper lobe and luminal narrowing at apical part of apicoposterior segment of left upper lobe (). Bronchial mucosal biopsy was performed at the both above segments. As bronchial washing fluids smear was positive acid fast bacilli, we started with standard antituberculous medication empirically. However, NTM was detected by polymerase chain reaction from the bronchial specimens and histologic findings at bronchial mucosa revealed chronic granulomatous inflammations with positive Ziehl-Neelsen stain (). One month later, M. kansasii was isolated in bronchial washing fluids and bronchial mucosa specimens. Finally, we diagnosed M. kansasii pulmonary disease with bronchial involvement and he was treated with isoniazid at 300 mg, rifabutin at 150 mg, and ethambutol at 1,200 mg. After the medication, his cough improved gradually and a chest X-ray after 18 months of treatment showed complete regression of the bilateral hilar lymphadenopathy ().