Can Germ Cell Tumors of the Ovary Spread to the Peritoneum?
Yes, ovarian germ cell tumors can definitively spread to the peritoneum through direct dissemination, and this peritoneal spread is incorporated into the FIGO staging system used for all ovarian malignancies, including germ cell tumors. 1
Mechanisms and Patterns of Peritoneal Spread
Ovarian germ cell tumors spread through the same mechanisms as epithelial ovarian neoplasms, utilizing three main pathways: lymphatic, hematogenous, and direct dissemination into body cavities such as the peritoneum. 2, 3 The peritoneum provides a unique microenvironment consisting of basement membrane, mesothelial cells, and connective tissue that tumor cells exploit for adhesion and implantation. 4
Germ cell tumors demonstrate multiple patterns of metastatic spread simultaneously, including peritoneal dissemination, lymphogenous metastasis, and hematogenous metastasis. 5 This is particularly important in growing teratoma syndrome, where mature teratomas can recur as pelvic peritoneal dissemination even after chemotherapy. 5, 6
Staging Implications
The FIGO staging system explicitly accounts for peritoneal spread in ovarian germ cell tumors:
- Stage IC3: Malignant cells in ascites or peritoneal washings 1
- Stage II: Pelvic extension to other pelvic intraperitoneal tissues 1
- Stage III: Cytologically or histologically confirmed spread to the peritoneum outside the pelvis 1
Clinical Significance and Surgical Management
Peritoneal spread has critical prognostic and therapeutic implications. Stage is the most important prognostic factor for ovarian germ cell tumors, with adverse factors including stage >I. 1 The staging procedure for germ cell tumors must include comprehensive peritoneal assessment: infracolic omentectomy, biopsy of diaphragmatic peritoneum, paracolic gutters, pelvic peritoneum, and peritoneal washings in macroscopic stage I disease. 1
Omission of staging peritoneal procedures increases recurrence rates, though without impact on overall survival given the high chemosensitivity of these tumors. 1 Any suspicious peritoneal areas or adhesions should be biopsied during surgical exploration. 1
Important Clinical Pitfalls
Growing teratoma syndrome represents a unique scenario where mature teratomas grow as peritoneal masses during or after chemotherapy, with the peritoneum being one of the most frequent sites. 5, 6 These masses contain only mature teratoma components but continue to enlarge, potentially infiltrating organs and causing complications. 6
Preoperative imaging has limitations: CT sensitivity for peritoneal metastases is only 28-51% despite high specificity. 4 Therefore, thorough surgical exploration and staging are essential.
Long-term surveillance is critical because peritoneal recurrences can occur years after initial treatment, necessitating whole-body imaging follow-up. 5
The high chemosensitivity of germ cell tumors means that even patients with peritoneal spread can achieve excellent outcomes with appropriate fertility-sparing surgery and adjuvant chemotherapy. 1, 3