Usefulness of Real-time PCR to DetectMycobacterium tuberculosisand Nontuberculous Mycobacteria

Nontuberculous mycobacterial pulmonary disease mimicking lung cancer: Clinicoradiologic features and diagnostic implications

To describe the features and clinical implications of computed tomography (CT), positron emission tomography (PET), and percutaneous needle aspiration biopsy (PCNB) in pulmonary nontuberculous mycobacterial (NTM) disease manifesting as a solitary nodule, mass, or mass-like consolidation mimicking malignancy.Among a cohort of 388 patients with NTM pulmonary disease, 14 patients with clinically and radiologically suspected lung cancer were included in our study. Two chest radiologists evaluated CT features, including lesion type (nodule, mass, or mass-like consolidation), morphologic features (margin, degree of enhancement, calcification), and presence of accompanying findings suggestive of NTM pulmonary disease (bronchiectasis with clustered centrilobular nodules or upper-lobe cavitary lesions) by consensus. Diagnostic procedures for microbiologic diagnosis of NTM disease and clinical outcome were reviewed.Incidence of NTM pulmonary disease presenting as solitary nodule/mass (n = 8) or mass-like consolidation (n = 6) was 3.6% (14 of 388). Most lesions were detected incidentally during routine health check-up or evaluation of other disease (11 of 14, 79%). Lesions typically showed poor contrast-enhancement (9 of 12) and internal calcification (6 of 14). No lesions had CT features suggestive of NTM pulmonary disease. All 4 lesions for which PET/CT imaging was performed showed strong fluorodeoxyglucose uptake simulating malignant lesions (mean, 4.9; range, 3.6-7.8). PCNB revealed mycobacterial histology in 6 of 11 specimens and positive culture results were obtained for 7 of 7 specimens.NTM pulmonary disease may present as a solitary nodule, mass, or mass-like consolidation mimicking malignancy. CT features and PCNB are important to diagnose NTM disease mimicking lung cancer to avoid unnecessary surgery.

[A case of gallbladder tuberculosis diagnosed by positive tuberculosis-polymerase chain reaction]

Gallbladder tuberculosis is an extremely rare disease that is rarely reported in the literature. Arriving at the correct diagnosis of gallbladder tuberculosis is difficult, and it is usually made by histopathologic examination after cholecystectomy. However, due to the low sensitivity of acid-fast stain and culture result, diagnosing gallbladder tuberculosis is still demanding even after tissue acquisition. To overcome this problem, tuberculosis-polymerase chain reaction (TB-PCR) is performed on the resected specimen, which has high sensitivity and specificity. A 70-year-old female who had previously undergone total gastrectomy for advanced gastric cancer was admitted with right upper quadrant pain. Abdominal ultrasonography and computed tomography revealed acute cholecystitis without gallstones or sludge. She underwent cholecystectomy and the histopathologic finding of the specimen showed chronic active cholecystitis without gallstones or sludge. Because she was suspected to have pulmonary tuberculosis, TB-PCR was also performed on the resected gallbladder. TB-PCR showed positive reaction for Mycobacterium tuberculosis and we could diagnose it as gallbladder tuberculosis. Herein, we present a case of gallbladder tuberculosis diagnosed by TB-PCR from resected gallbladder.