Abdominal hydatid disease and its mimics: a comprehensive pictorial review of imaging clues to the differential diagnosis.

backgroundHydatid disease (HD), also known as echinococcosis, is a parasitic disease caused by tapeworms. HD is endemic in many parts of the world and can affect virtually any organ system. Due to the rapid growth of worldwide migration, especially in recent decades, the disease can be diagnosed anywhere, particularly among immigrants in non-endemic areas.

objectiveTo illustrate the spectrum of abdominal imaging manifestations of HD and to review the principal benign and malignant abdominal cystic lesions that can mimic HD, using an organ-based approach with emphasis on imaging features that aid in differential diagnosis.

findingsRadiologic imaging is crucial for diagnosing HD, assessing disease activity, progression, and complications, and detecting stage- and organ-specific features. Hydatid disease in the abdomen can mimic other abdominal diseases, depending on the organ involved. Additionally, many other abdominal lesions can mimic hydatid disease and present with similar clinical symptoms. This pictorial review demonstrates characteristic imaging findings of HD and its mimics across the different abdominal organs and spaces, highlighting specific morphological features and potential diagnostic pitfalls. This review incorporates the World Health Organization Informal Working Group on Echinococcosis (WHO-IWGE) classification to provide a standardized framework for describing the imaging appearances of cystic echinococcosis.

conclusionRecognizing the characteristic imaging features of HD and its mimics is essential for accurate diagnosis and appropriate management. A systematic approach that incorporates lesion morphology, organ involvement, disease stage, and relevant clinical and epidemiological information can improve diagnostic confidence, enable early diagnosis, and help avoid misdiagnosis and inappropriate intervention.