Abstract:

Low-grade appendiceal mucinous neoplasm (LAMN) is a rare and heterogeneous gastrointestinal tumor. When LAMN secretes mucin that spreads into the peritoneal cavity, forming pseudomyxoma peritonei (PMP) and involving the ovarian, its clinical manifestations and auxiliary examinations are highly similar to those of ovarian mucinous tumors with pelvic and abdominal metastasis, which can easily lead to preoperative misdiagnosis. LAMN complicated by PMP has a high risk of postoperative recurrence, and standardized treatment can improve the prognosis. Given that the treatment regimens for LAMN and ovarian mucinous tumors are different, early identification of the tumor origin is the key to treatment. We report a case of a patient with LAMN complicated by PMP initially presenting as an ovarian tumor. The patient presented with abdominal distension and abdominal pain. Preoperative imaging studies suggested an ovarian tumor. Intraoperative pathological diagnosis indicated a borderline mucinous ovarian tumor, while postoperative pathology confirmed LAMN involving the ovaries. The patient refused hyperthermic intraperitoneal chemotherapy. After one year postoperative surveillance, no recurrence or metastasis was observed. This case aims to provide a reference for the clinical management of cases with difficult differential diagnosis between ovarian tumors and LAMN, so as to avoid misdiagnosis and inappropriate treatment.

Key words: Appendiceal mucinous neoplasms, Ovarian neoplasms, Pseudomyxoma peritonei, Misdiagnosis, Cytoreduction surgical procedures, Hyperthermic intraperitoneal chemotherapy