CRA17 UTILIZING MEDICAL THORACOSCOPY FOR THE DIAGNOSIS OF DIFFUSE LARGE B-CELL LYMPHOMA PRESENTING WITH PLEURAL EFFUSION

Ad Rian Chong¹, Khai Lip Ng¹, Nur Husna Mohd Aminudin¹, Kasuma Mohamed Nordin¹, Fazilah Hassan²
1 Division of Respiratory Medicine, Department of Internal Medicine, Melaka Hospital, Melaka, Malaysia
2 Department of Pathology, Melaka Hospital, Melaka, Malaysia

Introduction
Pleural effusion is a common manifestation in non-Hodgkin's lymphoma, typically indicating advanced disease and high tumour burden. Diagnosing lymphoma-related pleural effusions can be challenging, as conventional diagnostic tools like thoracentesis often fail due to subtle pleural involvement or scant malignant cells. Medical thoracoscopy, a minimally invasive procedure, allows direct visualization and targeted biopsy of pleural lesions, enhancing diagnostic accuracy.

Case Report
We report the case of a 22-year-old male presenting with a chronic dry cough, significant weight loss, and left-sided pleural effusion. Initial thoracentesis revealed lymphocyte-predominant exudative fluid, but cytology and microbiology were non-contributory. Imaging showed a large prevascular mediastinal mass with associated pleural effusion and widespread lymphadenopathy. A CT-guided biopsy of the mediastinal mass suggested B-cell lymphoma, but inadequate tissue limited immunohistochemical subtyping. Due to persistent diagnostic uncertainty, the patient underwent left-sided medical thoracoscopy. Multiple pleural nodular lesions were visualized and biopsied. Histopathology revealed diffuse infiltration of large atypical lymphoid cells. Immunohistochemistry confirmed Diffuse Large B-Cell Lymphoma (DLBCL), with CD20, PAX5, and BCL2 positivity and a high proliferation index (Ki-67: 80%). The patient subsequently received systemic chemotherapy, resulting in significant clinical and radiological improvement.

Discussion and Conclusion
This case highlights the limitations of standard diagnostic methods in evaluating lymphoma-related pleural effusions and underscores the pivotal role of medical thoracoscopy. By enabling direct pleural inspection and high-yield biopsies, thoracoscopy can facilitate definitive diagnosis and appropriate management, especially in cases where initial investigations are inconclusive. Given its diagnostic superiority and minimally invasive nature, thoracoscopy should be strongly considered in similar clinical scenarios.