Uterine leiomyoma with cystic degeneration misdiagnosed as an ovarian malignancy: A case report

Background: Uterine leiomyoma is the most common benign tumour of the female genital tract, but degenerative changes may produce atypical features that mimic ovarian malignancy. 

Case: We report miss AU, a 40-year-old nulliparous woman who presented with progressive abdominal distension, pain, and respiratory discomfort. Imaging studies demonstrated a large mixed solid–cystic abdominopelvic mass with ascites and elevated serum Cancer Antigen (CA)-125, raising suspicion of ovarian cancer. At exploratory laparotomy, two huge complex pedunculated uterine masses were seen alongside other smaller ones, with healthy-looking ovaries and fallopian tubes. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was done and histopathological analysis confirmed leiomyoma with cystic degeneration without any malignant features. The postoperative course was uneventful, and follow-up remained satisfactory. 

Discussion: Degenerative uterine leiomyomas often have atypical ultrasonographic features that obscure their uterine origin and can closely mimic ovarian or malignant adnexal masses, especially when cystic change is present. Although MRI provides the most reliable differentiation through characteristic signal patterns and demonstration of uterine attachment, limited availability and cost of advanced imaging and non-specific tumour markers make accurate diagnosis challenging in many settings.

Conclusion: This case underscores the diagnostic challenge posed by degenerative uterine leiomyomas and emphasizes the need to consider them in the differential diagnosis of suspected ovarian malignancy in women of reproductive age.