Fine-Needle Aspiration Cytology of Hepatic Hydatid Disease: A Five-Year Case Series with Emphasis on Diagnostic Limitations

INTRODUCTION: Hydatid disease caused by Echinococcus granulosus is a major health problem in endemic regions. Hepatic cysts may mimic simple cysts or neoplasms, creating diagnostic challenges. Fine-needle aspiration cytology (FNAC) provides a rapid diagnosis, but its role remains debated due to variable sensitivity and concerns regarding safety. METHODS: We retrospectively analyzed 15 patients with hepatic and hepatobiliary cystic lesions evaluated in our pathology department over a 5-year period. Fourteen patients underwent ultrasound-guided FNAC, and 1 patient had an incidental retroperitoneal mass biopsied during cholecystectomy. Smears were stained with May-Grünwald-Giemsa and examined for protoscolices, laminated membranes, scolices, hooklets, and background inflammatory response. Biopsy tissue was processed with hematoxylin-eosin (H&E). RESULTS: The cohort included 14 FNAC cases, 7 (50%) demonstrated diagnostic features of Echinococcus, while 7 (50%) yielded only histiocytes, necrotic debris, or nonspecific inflammation. The biopsy revealed chronic cholecystitis with echinococcal structures. The patient developed postoperative complications and died on postoperative day 2. CONCLUSION: FNAC provides a rapid and specific diagnosis of hepatic hydatid cysts when characteristic elements are identified, but half of aspirates may be nondiagnostic. Our findings highlight both the utility and limitations of FNAC and underscore the importance of multimodal correlation with imaging, serology, and histopathology for safe and accurate patient management.