Background <p>Echinococcosis classifies as a helminthic zoonosis affecting more than 3 million people. The outcome depends on the affected organ and implicated structures, with a lack of treatment in the long-term resulting in up to 90% of patients dying; even after treatment, the overall lifespan is reduced by 1–2&#xa0;years. Postoperative death can reach as high as 2.2% if <i>E. granulosum</i> cysts are involved with organs other than the liver and lungs, which&#xa0;are considered very rare. This case aims to document this unique and personalized surgical approach for this rare presentation of splenic hydatid cysts.</p> Case presentation <p>We present the case of a 43-year-old white female patient of Central European (Swiss) ethnic background who presented with an Echinococcus infection of the spleen. Following a biking accident, a chest x-ray incidentally revealed a solitary hydatid cyst in the spleen, characterized by extensive plate-like wall calcifications and measuring over 8-cm in length.&#xa0;The unilocular characteristics with a thick wall presence in combination with a high degree of calcification, absence of daughter cysts, positive serum markers are characteristic of a type V hydatid cyst (Gharbi classification)/CE5m (World Health Organization–Informal Working Group on Echinococcosis classification).</p> <p>With guidelines lacking a diagnostic and preoperative investigation pathway for splenic involvement, we conducted a full series with three dimensional reconstruction in computed tomography and magnetic resonance imaging of the anatomical relationship between the hydatid cyst and surrounding parenchymatous organs.</p> <p>Owing to chronic inflammation, extensive adhesions, and a cyst twice the size of the spleen with close localization to the hilum, an open surgical approach was conducted. The risk of spontaneous rupture and anaphylactic shock, especially with likely prior hemorrhage, further supported this decision. To minimize recurrence and complications, total pericystectomy with splenectomy was performed. Perioperative immunization was ensured to prevent overwhelming postsplenectomy infection.</p> <p>After 6&#xa0;weeks of preoperative albendazole therapy, total splenectomy in hydatid cyst infestation offers the advantage of reduced intraoperative risk and lower recurrence rate.</p> <p>A follow-up 1&#xa0;month, and 4&#xa0;month postintervention including clinical evaluation, imaging, and laboratory findings were inconspicuous, revealing no need for further intervention.</p> Conclusion <p>Thus far, only consensus among experts can be retrieved when making decisions regarding the treatment of splenic involvement of hydatid cysts. This unique case of successful cyst removal via total splenectomy, with an uncomplicated postoperative course, contributes to the development of treatment guidelines for splenic hydatid cysts. The Valais region should be recognized as an additional risk factor for echinococcal infection, particularly owing to the consumption of wild berries and contaminated food or water. Given the chronic inflammation, potential adhesions, and cyst size—twice the size of the spleen—an open surgical approach was deemed necessary. The risk of hemorrhage and spontaneous rupture further justified surgical excision to minimize recurrence and complications. Adequate perioperative immunization was implemented to prevent overwhelming postsplenectomy infection. Although hepatic hydatid cyst management is well-established, splenic involvement requires a patient-centered, organ-specific approach owing to unique anatomical and immunological considerations.</p>