T-lymphoblastic lymphoma presenting as massive pleuro-pericardial effusions: a rare diagnostic challenge in TB endemic regions.

A married woman in her early 30s presented with 2 months of dry cough, progressive dyspnoea and weight loss. Imaging revealed massive right pleural and severe pericardial effusions with a large anterior mediastinal mass. Initial lymphocyte-predominant exudative effusion suggested tuberculous pleuritis, but cytology was inconclusive. Thoracoscopic pleural biopsy with immunohistochemistry showed TdT-positive and CD7-positive lymphoid cells, establishing a diagnosis of T-lymphoblastic lymphoma (T-LBL) involving the pleura, pericardium and mediastinum. She received acute lymphoblastic leukaemia-type multi-agent chemotherapy and remains well, with no recurrence of effusion on follow-up. This case highlights the diagnostic challenge of distinguishing rare lymphomas from common infections in tuberculosis-endemic regions and underscores the necessity of early tissue diagnosis with immunophenotyping when faced with unexplained large pleuro-pericardial effusions. Prompt recognition is crucial because T-LBL requires intensive ALL-type therapy, which significantly improves survival compared with conventional lymphoma regimens.