Lung and Nodal Involvement in Nontuberculous Mycobacterial Disease: PET/CT Role.

INTRODUCTION: Systematic use of (18)F-FDG PET/CT has the potential to simultaneously assess both pulmonary and lymph node involvement in nontuberculous mycobacterial (NTM) lung infection. OBJECTIVE: The aim of the study was to evaluate the role of (18)F-FDG PET/CT in the assessment of both mediastinal lymph nodes and lung involvement in NTM patients compared with active tuberculosis (TB) patients. METHODS: 26 patients with pulmonary NTM disease were selected; six consecutive patients had undergone (18)F-FDG PET/CT and data was compared with 6 active TB patients. RESULTS: NTM exhibited different radiological lung patterns with an average SUV max value at PET/CT scan of 3,59 ± 2,32 (range 1,14 to 9,01) on pulmonary lesions and a mean value of SUV max 1,21 ± 0,29 (range 0,90 to 1,70) on mediastinal lymph nodes. Pulmonary lesions in TB showed an average SUV max value of 10,07 ± 6,45 (range 1,20 to 22,75) whilst involved mediastinal lymph nodes exhibited a mean SUV max value of 7,23 ± 3,03 (range 1,78 to 15,72). CONCLUSIONS: The differences in PET uptake in a broad range of lung lesions and lymph nodes between NTM and M. tuberculosis patients suggest a potential role for PET/CT scan in the diagnosis and management of pulmonary mycobacterial disease.

Detection of skeletal muscle metastases on initial staging of lung cancer: a retrospective case series.

PURPOSE: Estimation of skeletal muscle metastases (SMMs) at the time of diagnosis and/or initial staging of lung cancer. MATERIALS AND METHODS: Retrospective evaluation of clinical charts and imaging data suggestive of SMMs of patients with histology-proved lung cancer over a 5-year period. RESULTS: SMMs were identified in 46 out of 1,754 patients. Single and multiple (62.9% of cases) SMMs were detected by total body multi-detector computed tomography (MDCT). They were associated with poorly differentiated (43%) and advanced adenocarcinomas (52%) without clinically relevant symptoms and/or signs. Psoas and buttock muscles were most frequently involved (33.3%). MDCT findings consisted of well-defined homogeneously hyperdense oval masses (31%), lesions with ring-like enhancement and central hypoattenuation (68%), or large abscess-like necrotic lesions (24%). Sonography revealed well-defined hypoechoic masses (41.6%), ill-defined hypoechoic lesions (33.3%), or anechoic areas with a necrotic centre (25%). Positron emission tomography revealed that all SMMs were metabolically active. CONCLUSIONS: SMMs are uncommon but not negligible in lung cancer, with an estimated prevalence of 2.62% in our series. Although histology remains the recommended method, use of high-performance imaging techniques and increased clinical suspicion may improve their early detection. Efforts addressing their effect on the natural history of lung cancer are needed.