Schistosomiasis mansoni is a parasitic disease caused by Schistosoma mansoni, which predominantly affects the hepatosplenic system. Although the hepatic form is the most common, pulmonary complications are rare and less recognized, but can have serious clinical consequences. This report describes a rare case of schistosomiasis mansoni with significant pulmonary involvement, highlighting the importance of early diagnosis and appropriate management of these complications. A 48-year-old male farmer living in a rural area in Itabuna, Bahia, an endemic region for schistosomiasis, presented to the health service complaining of progressive dyspnea for two months, associated with dry cough and sporadic chest pain. He denied hemoptysis, but reported unintentional weight loss and intermittent low-grade fever. The patient had been diagnosed with the disease 10 years ago, but never completed treatment. The physical and clinical examination revealed signs of chronic liver disease, such as collateral circulation and hepatosplenomegaly, in addition to bibasilar rales on pulmonary auscultation. Laboratory and imaging tests revealed significant eosinophilia (12%), slightly elevated liver enzymes, bilateral infiltrates (chest X-ray), and nodular lesions with peripheral distribution (chest computed tomography (CT), suggesting possible granulomatous involvement. Serology for other lung infections was negative. Given the clinical history and other findings, a CT-guided lung biopsy was performed, which revealed epithelioid granulomas without central necrosis, with viable and calcified eggs of S. mansoni. The test for eggs in the blood was positive, confirming the diagnosis of pulmonary complications due to schistosomiasis. The patient was treated with a single dose of praziquantel, followed by corticosteroid therapy to manage the lung inflammation. There was significant improvement in respiratory symptoms after six weeks, with partial resolution of lung lesions observed on repeat CT. Pulmonary involvement in schistosomiasis is rare and may be underdiagnosed, since respiratory symptoms can be confused with other diseases, such as tuberculosis. The presence of pulmonary granulomas and S. mansoni eggs outside the gastrointestinal tract highlights the ability of the parasite to cause disseminated disease, complicating the clinical picture and making management more challenging. This report highlights the importance of considering schistosomiasis in the differential diagnosis, in addition to emphasizing the importance of continued surveillance for extrahepatic complications, particularly in endemic areas. The inclusion of advanced diagnostic methods, such as CT-guided lung biopsy, may be crucial for identifying rare manifestations. Correct patient counseling on the importance of complete treatment and regular monitoring are essential to prevent serious complications and improve clinical outcomes.
