Abstract Schistosomiasis is a parasitic infection caused by blood flukes of the genus Schistosoma. Pulmonary schistosomiasis may manifest as ground-glass opacities or pleural effusions in the acute phase, and commonly as pulmonary hypertension in the chronic phase. We present a case of chronic pulmonary schistosomiasis mimicking metastatic malignancy in a patient from an endemic region presenting with multiple solid pulmonary nodules. A 66-year-old male with a history of hypertension and diabetes mellitus experienced an acute onset of fever, chills, and generalized weakness one day after migrating from Nigeria to the United States. Despite taking antimalarial medications, his symptoms progressed, prompting his hospitalization. Initial laboratory tests revealed transaminitis and thrombocytopenia, while a respiratory viral panel, HIV screen, acute hepatitis panel, and malaria studies were negative. No peripheral eosinophilia noted. Chest CT demonstrated multiple solid pulmonary nodules, the largest measuring 2.5 × 1.8 cm in the left lower lobe, along with mediastinal lymphadenopathy. A CT of the abdomen and pelvis revealed a 3.2 cm renal mass, raising concern for metastatic cancer. He was treated empirically with ceftriaxone and doxycycline, with clinical improvement, and discharged to follow-up with interventional pulmonology as an outpatient.Three months later, repeat imaging showed stable pulmonary nodules. He subsequently underwent robotic-assisted navigational bronchoscopy with cryobiopsies of the left lower lobe nodule and endobronchial ultrasound-guided transbronchial needle aspirations of station 4R lymph nodes. Biopsy revealed benign lung parenchyma with scattered calcified spindle-shaped material and rare eggs with lateral spines, consistent with Schistosoma mansoni. Lymph node aspirates were negative for malignancy. Transthoracic echocardiography showed no evidence of pulmonary hypertension, and abdominal ultrasound was without findings of portal hypertension. Stool testing for ova and parasites was negative for Schistosoma. Strongyloides serology was negative. The patient was treated with praziquantel and reported clinical improvement.Pulmonary schistosomiasis is typically caused by S. mansoni, S. haematobium, and S. japonicum. The acute phase, known as Katayama syndrome, reflects a hypersensitivity response to migrating schistosomula and may present with fever, cough, and peripheral eosinophilia. Chronic pulmonary schistosomiasis more commonly leads to pulmonary hypertension due to granulomatous inflammation and vascular remodeling induced by egg embolization. However, localized pulmonary nodules or masses, as seen in this case, are rare and represent ectopic deposition of eggs outside their typical portal-mesenteric and genitourinary sites. This case highlights the importance of considering parasitic infection in the differential diagnosis of pulmonary nodules in patients from endemic regions. This abstract is funded by: None
Adderley et al. (Fri,) studied this question.