Gliomatosis peritonei with ovarian teratoma: an international multicenter case series

Gliomatosis peritonei (GP) is a rare condition characterized by peritoneal implants of mature glial tissue, macroscopically resembling peritoneal carcinomatosis. It is usually associated with ovarian mature or immature teratoma. To describe the clinical characteristics, treatment, and prognosis of cases with GP.

Multi-center retrospective study of patients diagnosed with ovarian teratoma and GP between 2000 and 2023. Non-gynecological GP cases were excluded.

Overall, 23 patients were included. Median age was 25 years (range; 10-38). Median ovarian tumor size was 19 cm (range; 6-35). The main symptom was abdominal pain (n = 13). Histology was mature teratoma in 13% (n = 3), and immature teratoma in 87% (n = 20) of cases, of which 90% (n = 18) was pure teratomas and 10% (n = 2) was mixed with yolk sac tumor. Overall, 60% were grade 3. Fertility-sparing surgery was performed in 87% (n = 20, of them 18 underwent unilateral salpingo-oophorectomy and 2 cystectomy ± further biopsies) without macroscopic residual disease in 91% (n = 21), and 78% (n = 18) were diagnosed at stage I. Adjuvant chemotherapy was given in 7 cases, only with grade 2 or more. Twelve women relapsed after a median of 43 months. However, only 2 relapses had immature teratoma components. Three patients had a second relapse after a median of 9 months. Over a median follow-up of 81 months (range; 7-270), the entire cohort remained alive and 3 live births were reported.

GP is mostly associated with high-grade early-stage immature teratoma in young patients. Resection of peritoneal implants is crucial for the accurate diagnosis and optimal treatment planning. Relapses are mostly mature, therefore, offering fertility-sparing treatment in pre-menopausal cases could be considered.