Case Report: Isolated splenic hydatid cyst with negative serology managed by laparoscopic splenectomy.

Background: Hydatid disease caused by Echinococcus granulosus is a zoonosis endemic in many parts of the world. While hepatic and pulmonary involvements are common, isolated splenic hydatidosis remains extremely rare, representing less than 4% of all cases. Diagnosis can be further complicated by false-negative serological tests. Case presentation: We report the case of a 31-year-old female presenting with isolated left upper quadrant pain. Physical examination and baseline laboratory tests were unremarkable. Abdominal ultrasound and computed tomography (CT) revealed a well-circumscribed, homogeneous, hypodense oval mass (50×57×56 mm) at the upper pole of the spleen with a thin wall displaying a focal calcification. Hydatid serology was negative. Given the high suspicion of a hydatid cyst, pre-splenectomy immunizations were administered, and the patient underwent an exploratory laparoscopy. Intraoperative findings confirmed a splenic hydatid cyst, and a total laparoscopic splenectomy was performed. The postoperative course was uneventful. Histopathological examination confirmed the diagnosis. Conclusion: Clinicians should maintain a high index of suspicion for hydatid disease in patients presenting with cystic splenic masses in endemic areas, even in the presence of negative serology. Laparoscopic splenectomy is a safe and effective approach when strict hydatid safety measures are respected.