Pseudomesotheliomatous Carcinoma of the Lung in a Young Nonsmoker: A Rare Case Mimicking Malignant Mesothelioma

Pseudomesotheliomatous carcinoma of the lung (PCL) is a rare form of lung adenocarcinoma.It mainly affects the pleura and has a clinical, radiological, and histological presentation that closely resembles malignant pleural mesothelioma (MPM).We report a case of a 36-year-old nonsmoking male with no known asbestos exposure who experienced sudden shortness of breath and a dry cough.Imaging showed loculated pleural effusion with diffuse pleural thickening and no visible lung mass.Cytological examination, histopathology, and immunohistochemistry (IHC) confirmed the diagnosis of PCL.This case highlights the diagnostic challenges linked to this rare condition, especially in younger patients without typical risk factors.It also emphasizes the crucial role of IHC and molecular testing in confirming the diagnosis.