Massive Cystic Degeneration of a Uterine Leiomyoma in a Patient with Autosomal Dominant Polycystic Kidney Disease

Background: A uterine cyst occurring as an extrarenal manifestation of autosomal dominant polycystic kidney disease (ADPKD) is extremely rare. Case: A 46-year-old Japanese woman was referred with a large abdominal mass causing severe abdominal distension. A large uterine cyst as an extrarenal manifestation of ADPKD was strongly suspected. First, we managed this patient by aspirating the cyst fluid through a small laparotomy. A year later, the cyst recurred and the patient underwent hysterectomy. Massive cystic degeneration of a uterine leiomyoma was diagnosed histologically. Conclusion: We described the rare case of massive cystic degeneration of a uterine leiomyoma in a patient with ADPKD, in which a causal relationship was suspected.