Rare anatomical localizations of primary hydatid cysts: A single-center retrospective observational study.

Objective: To describe the clinical, radiological, and surgical characteristics of primary hydatid cysts arising in uncommon anatomical locations other than the liver and lungs. Material and Methods: This single-center retrospective observational study included 523 patients who underwent surgical treatment for hydatid disease at Servergazi State Hospital, Denizli, Türkiye, between January 2009 and June 2024. Patients with hepatic or pulmonary involvement, a history of previous hydatid surgery, or multi-organ disease were excluded. Demographic characteristics, clinical presentations, cyst localizations, diagnostic modalities, and treatment approaches were systematically recorded. Diagnostic evaluation was based on serological assays and imaging techniques, including ultrasonography, computed tomography, and magnetic resonance imaging. Results: Of the 523 patients evaluated, 29 (5.5%) were identified as having primary hydatid cysts in atypical anatomical locations. The spleen was the most frequently involved site, followed by musculoskeletal structures, the central nervous system, and various soft tissue localizations. Serological tests were positive in 82.7% of cases. All patients underwent surgical management tailored to cyst location, and postoperative albendazole therapy was administered. Postoperative complications were limited, and no procedure-related mortality was observed. Conclusion: Primary hydatid cysts may present in a wide spectrum of uncommon anatomical locations and often manifest with non-specific clinical features. Awareness of these atypical presentations is essential for accurate diagnosis and appropriate surgical management, particularly in endemic regions.