A PET-CT score for discriminating malignant from benign pleural effusions.

BACKGROUND AND OBJECTIVES: The results of previous PET-CT studies are contradictory for discriminating malignant from benign pleural effusions. We purpose to develop a PET-CT score for differentiating between benign and malignant effusions. PATIENTS AND METHODS: We conducted a prospective study of consecutive patients with pleural effusions undergoing PET-CT from October 2013 to October 2019 (referral cohort). PET-CT scan features evaluated using the SUV were: linear thickening; nodular thickening; nodules; masses; circumferential thickening; mediastinal and fissural pleural involvement; intrathoracic lymph nodes; pleural loculation; inflammatory consolidation; pleural calcification; cardiomegaly; pericardial effusion; bilateral effusion; lung mass; liver metastasis and other extra-pleural malignancy. The results were validated in an independent prospective cohort from November 2019 to June 2021. RESULTS: One hundred and ninety-nine patients were enrolled in the referral cohort (91 with malignant effusions and 108 benign). The most useful parameters for the development of a PET-CT score were: nodular pleural thickening, pleural nodules with SUV>7.5, lung mass or extra pleural malignancy (10 points each), mammary lymph node with SUV>4.5 (5 points) and cardiomegaly (-1 point). With a cut-off value of >9 points in the referral cohort, the score established the diagnosis of malignant pleural effusion with sensitivity 87.9%, specificity 90.7%, positive predictive value 88.9%, negative predictive value 89.9%, positive likelihood ratio 7.81 and negative likelihood ratio 0.106. These results were validated in an independent prospective cohort of 75 patients. CONCLUSIONS: PET-CT score was shown to provide relevant information for the identification of malignant pleural effusion.

Radiological findings of unilateral tuberculous lung destruction.

OBJECTIVES: The aim of this report is to identify the radiological findings of unilateral tuberculous lung destruction (UTLD). MATERIALS AND METHODS: Thirteen patients with (UTLD) were reviewed from 1999 to 2014. Only patients with radiological evidence of absence of pulmonary parenchyma preserved were included. Clinical and demographic data were obtained and radiological studies (chest radiograph and CT) were retrospectively reviewed. RESULTS: The left lung was more commonly involved (85%). The following radiological findings were found in all cases: a decrease in the diameter of the pulmonary vessels of the affected lung, herniation of the contralateral lung and hypertrophy of the ribs and/or thickening of extrapleural fat. Two radiological patterns were identified: UTLD with cystic bronchiectasis (85%) and UTLD without residual cystic bronchiectasis (15%). Forty-six per cent of cases had respiratory infection symptoms with presence of air-fluid levels in the affected lung as the most common finding in these patients. CONCLUSIONS: Total unilateral post-tuberculous lung destruction is an irreversible complication with the following main radiological features: predominantly left-sided location, decreases in the diameter of the ipsilateral pulmonary vessels, herniation of the contralateral lung and hypertrophy of the ribs and/or thickening of extrapleural fat. TEACHING POINTS: • Unilateral tuberculous lung destruction is an irreversible complication of tuberculosis. • Left-side predominance and herniation of the contralateral lung are characteristic. • Decreased diameter of the ipsilateral pulmonary vessels occurred in all patients. • The pattern with residual cystic bronchiectasis is the most frequent. • Superimposed non-tuberculous infections may affect the destroyed lung.