Supplementary Material for: Pleural Effusion with Schistosoma Ova in Cytologic Smears: A Rare Case Report in an Elderly Patient

Background: Schistosomiasis is a chronic parasitic disease with diverse clinical manifestations. Thoracic involvement is uncommon, and pleural effusion due to schistosomiasis is exceptionally rare. Cytological identification of Schistosoma ova in pleural fluid represents a valuable diagnostic finding in such atypical presentations. Case presentation: A 79-year-old male patient presented with a pleural effusion persisting for several months. Diagnostic thoracentesis was performed, and pleural fluid was submitted for cytological evaluation. Microscopic examination revealed erythrocytes, inflammatory cells, and characteristic Schistosoma ova, establishing the diagnosis of pleural schistosomiasis. No malignant cells were identified. The patient was subsequently treated, resulting in clinical improvement. Conclusion: This case highlights the pivotal role of pleural fluid cytology in the diagnosis of rare thoracic manifestations of schistosomiasis. Recognition of Schistosoma ova in cytological specimens allows for timely diagnosis and appropriate management, particularly in patients with persistent pleural effusion of unclear etiology.