Pseudomyxoma peritonei from an ovarian mucinous cystadenoma mimicking ovarian cancer

Abstract

Pseudomyxoma peritonei (PMP) is a rare, borderline malignant condition, most commonly originating from the appendix, with ovarian origin being extremely rare. Rupture of ovarian mucinous tumours can result in dissemination of gelatinous mucus and tumour cells throughout the peritoneal cavity, leading to accumulation of ascites. We report a 56-year-old grand multiparous woman presenting with chronic abdominal pain and progressive distension. Physical examination revealed stable vital signs and overweight status (BMI 27 kg/m²). Laboratory investigations showed mild anaemia, and preoperative serum tumor markers (CA-125, CEA, CA 19-9) were evaluated. Imaging revealed a large multiloculated pelvi-abdominal cystic mass (22×19 cm) with massive ascites and peritoneal calcifications, suggestive of ovarian malignancy. An exploratory laparotomy revealed a 20 cm left ovarian mass with solid and multiloculated gelatinous components, with an appendix slightly enlarged, while the right adnexa and the uterus were unremarkable. Accidental intraoperative rupture released approximately 3 liters of gelatinous ascites. The patient underwent left salpingo-oophorectomy, appendectomy, multiple peritoneal biopsies, and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). Histopathology confirmed PMP originating from an ovarian mucinous cystadenoma.The patient remains under regular surveillance. Complete cytoreductive surgery with HIPEC offers the best prognosis, though long-term follow-up is essential due to the risk of recurrence. Ovarian-origin PMP is rare and may mimic advanced ovarian malignancy. Accurate diagnosis relies on histopathology, and management requires complete cytoreduction combined with HIPEC, with vigilant long-term follow-up.