A case report of an incidentally diagnosed primary isolated splenic hydatid cyst: the therapeutic dilemma of surgery versus watchful waiting.

Introduction and importance: The incidence of splenic hydatid cyst is 1%, and it comprises 0.5-4% of abdominal hydatid cysts. Primary hydatid cyst of the spleen is rare even in endemic areas, comprising only 2% of all splenic hydatid cysts. This case is unique due to the incidental finding of a rare isolated splenic hydatid cyst without other organ involvement. It raises surgeon awareness of atypical presentations, aiding diagnosis and guiding timely intervention versus watchful waiting. Case presentation: A 36-year-old female was incidentally diagnosed with a splenic hydatid cyst during radiological evaluation as part of a routine health check-up. Clinical examination revealed no significant findings, and baseline blood investigations were within normal limits. She underwent splenectomy successfully and was discharged on the fourth postoperative day with advice to continue albendazole for 1 more month. Clinical discussion: The membrane of a splenic hydatid cyst is typically thin, delicate, and fragile, in contrast to the hepatic hydatid cyst, which has a thicker and more robust wall. The risk of spontaneous or traumatic rupture is higher in splenic hydatid cysts compared to hepatic hydatid cysts. Thus, splenectomy is a safe and widely accepted option for splenic hydatid cysts. Conclusion: Watchful waiting is generally not recommended for Type I and Type III splenic hydatid cysts, even in asymptomatic or incidentally detected cases, whereas it may be considered in selected cases of hepatic hydatid cysts. In addition, watchful waiting can be considered in Type IV and Type V splenic hydatid cysts, as these represent inactive stages.