Basic and Clinical Sciences Examination (BCSE) Practice Exam 2026 – Comprehensive All-in-One Guide for Exam Success

Unilateral involvement is a common characteristic of pleural effusions in patients with tuberculosis (TB). In TB, the infection primarily affects one lung, leading to the accumulation of fluid in the pleural space on that side. While it's possible for TB to affect both pleurae, it is more frequently associated with unilateral pleural effusion, which can be a result of the localized inflammation and infection in the lung tissue.

Other options are less characteristic of TB-related pleural effusions. For instance, pleural effusions due to TB typically don't resolve completely without treatment, indicating that medical intervention is often necessary to address the underlying infection and fluid accumulation. It's also not accurate to say that pleural effusions are always bilateral; while they can be, this is not a defining feature. Moreover, the presence of pus suggests an empyema, which is a specific type of pleural effusion that may occur in TB cases, but the presence of non-purulent effusions is common as well. Thus, unilateral involvement stands out as the primary characteristic in the context of TB-related pleural effusions.