The diagnosis of tuberculous pleurisy (TP) can be difficult, and a pleural biopsy is frequently necessary. Enlargement of the internal mammary lymph node (IMLN) has been hypothesised to play a potential function and may be used as a method to raise the pre-test probability of TP. By comparing its prevalence and test results to those seen in patients with infectious, non-tuberculous pleurisy (NTIP) and in controls free from respiratory disorders, the current analysis sought to evaluate the function of IMLN involvement in TP in a multi-centric case-control study (CP). Patients with TP and NTIP from all of Italy's pulmonology units were included in the study. Concordance between chest computed tomography (CT scan) and thoracic ultrasound (TUS) measurements, as well as prevalence, accuracy, and predictive values of ipsilateral IMLN involvement between cases and control groups, were evaluated. In comparison to the NTIP and CP groups, TP had a considerably higher rate of ipsilateral IMLN involvement. Age-specific test performance results showed that patients older than years had a strong positive predictive value and older patients had a high negative predictive value. There was only fair agreement between the CT scan and ultrasonography. When determining the pre-test probability of TP, consideration of IMLN involvement is important. A tool that can direct the diagnostic work-up of suspected TP is essential, especially given the rising global frequency of mycobacterial infections.
