Challenges in Diagnosing Pleural Thickening: Primary Pleural Follicular Lymphoma

This is the case of a 66 -year -old male with a medical history of HIV infection on combination antiretroviral therapy (cART) who presented to the hospital with gradually worsening chronic right -sided chest and abdominal pain over the past three months. Computed tomography (CT) with contrast showed new masslike pleural thickening in the right lower lobe posteriorly with an associated small loculated right pleural effusion. A core needle pleural biopsy was performed, and the results were consistent with primary pleural malignant lymphoma. Histopathological and immunohistochemical examinations revealed CD10-positive, low-grade B -cell lymphoma. This case is considered a rare occurrence of primary malignant lymphoma developing in the pleura.