Healthcare burden and clinical spectrum of symptomatic polycystic liver disease in Japan: a nationwide epidemiological survey

Abstract Background Polycystic liver disease (PLD) is often asymptomatic, but some patients develop symptoms or complications requiring care or intervention. The nationwide burden of symptomatic PLD remains poorly defined. We conducted a nationwide survey to estimate the number and prevalence of patients with symptomatic PLD in Japan and characterize clinical features, treatment patterns, healthcare utilization, and outcomes. Methods A nationwide two-stage questionnaire survey was conducted. Symptomatic PLD was defined as 10 or more hepatic cysts with cyst-related symptoms or complications. In the first-stage survey, 3127 departments were selected by stratified random sampling to estimate the number of patients treated or followed up during 2021–2023. In the second-stage survey, clinical data were collected for patients treated or followed up in 2023. Results The estimated number of patients was 6500 during 2021–2023 and 3570 in 2023, corresponding to an annual prevalence of 28.6 per million. Among 557 patients with clinical data, 62% were female and 67.2% met the diagnostic criteria for polycystic kidney disease. Abdominal distension, abdominal pain, and cyst infection were the most frequent manifestations. More than half underwent hepatic cyst treatment, and 60.4% required consultation with other departments or institutions. Cyst infection and liver failure accounted for a subset of deaths. Mortality differed significantly among Gigot classification groups and was highest in type III. Conclusions This nationwide survey provides the first comprehensive epidemiological and clinical characterization of symptomatic PLD in Japan and establishes a benchmark for future disease severity classification, clinical management, and prospective studies.