Low-grade appendiceal mucinous adenocarcinoma with peritoneal and ovarian spread: a case report and literature review

Appendiceal mucinous neoplasms are rare and often present with nonspecific symptoms, leading to diagnostic challenges. This case report describes an atypical presentation of a low-grade mucinous appendiceal adenocarcinoma initially misdiagnosed as an ovarian mass, highlighting the importance of a multidisciplinary diagnostic approach. This case report involves a 57-year-old postmenopausal woman presented with persistent gastroesophageal reflux disease (GERD) and was found to have a large abdominopelvic cystic mass on imaging, suggestive of ovarian origin. Further evaluation, including computed tomography (CT), magnetic resonance imaging (MRI), and histopathological analysis after exploratory laparotomy, revealed a metastatic low-grade mucinous appendiceal adenocarcinoma with peritoneal dissemination (pseudomyxoma peritonei). The patient was referred for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). This case illustrates the diagnostic complexity of appendiceal mucinous neoplasms, particularly when mimicking gynaecological pathology. A high index of suspicion, comprehensive imaging, and histopathological confirmation are crucial for accurate diagnosis. CRS and HIPEC remain the standard of care for advanced disease, emphasizing the need for early multidisciplinary involvement in management.