Introduction: Schistosomiasis, also known as bilharzia, is a chronic tropical parasitic disease that remains highly endemic in many regions of the world, particularly in Madagascar. The most common clinical presentations involve the digestive, urogenital, and hepatosplenic systems. However, chronic schistosomal lesions may occasionally present as pseudotumoral masses mimicking malignant neoplasms, leading to major diagnostic challenges. This study aimed to report three cases of giant pseudotumoral schistosomiasis diagnosed by histopathological examination.

Cases Presentation: Three women originating from endemic regions of Madagascar were included in this study. The first patient, a 35-year-old woman from the Vatovavy region, presented with a large anal mass. Histopathological examination revealed schistosome eggs surrounded by eosinophil-rich granulomatous inflammation. The second patient, a 41-year-old woman from Haute Matsiatra, presented with chronic epigastric pain. Upper gastrointestinal endoscopy revealed a large budding gastric lesion, and histological analysis confirmed a schistosomal pseudotumor. The third patient, a 35-year-old woman also originating from Haute Matsiatra, presented with an intraperitoneal mass associated with bowel obstruction syndrome. Histopathological examination demonstrated partially calcified schistosome eggs embedded within fibro-myxoid tissue.

Conclusion: Giant pseudotumoral schistosomiasis represents a rare but clinically important manifestation of chronic schistosomal infection. It may closely mimic malignant tumors, particularly when presenting as digestive, anal, or abdominal masses. In endemic regions, schistosomiasis should therefore be considered in the differential diagnosis of tumor-like lesions. Histopathological examination remains the cornerstone of diagnosis, allowing identification of parasitic eggs, characterization of granulomatous inflammation, and exclusion of associated malignancy.