How Are Ovarian Sex Cord–Stromal Tumors Staged?

Ovarian sex cord–stromal tumors are a rare and heterogeneous group of neoplasms arising from the supportive and hormone-producing cells of the ovary—including granulosa cells, theca cells, Sertoli cells, and Leydig cells. Unlike epithelial ovarian cancers, these tumors are typically diagnosed at an early stage and carry a more favorable prognosis. Staging follows the International Federation of Gynecology and Obstetrics (FIGO) 2014 staging system for ovarian, fallopian tube, and primary peritoneal carcinomas—though it is applied with important caveats specific to sex cord–stromal tumors.

Stage I disease is confined to one or both ovaries. Substages reflect tumor size, capsule integrity, and surface involvement: Stage IA denotes tumor limited to one ovary with an intact capsule and no surface implants; IB involves both ovaries but retains intact capsules; IC indicates rupture of the capsule, surgical spill, or positive peritoneal washings—regardless of whether the tumor is unilateral or bilateral.

Stage II signifies pelvic extension beyond the ovaries—such as involvement of the uterus, fallopian tubes, or other pelvic structures—but without spread to the upper abdomen or lymph nodes. Stage IIA includes extension to the uterus or tubes; Stage IIB encompasses involvement of other pelvic tissues.

Stage III reflects microscopic or macroscopic peritoneal metastases outside the pelvis, or regional lymph node metastasis. Stage IIIA1 is defined by metastases ≤10 mm in size confined to pelvic or para-aortic lymph nodes; IIIA2 involves microscopic peritoneal implants beyond the pelvis (e.g., on the omentum or bowel serosa); IIIB features macroscopic implants ≤2 cm outside the pelvis; and IIIC includes implants >2 cm or positive retroperitoneal lymph nodes.

Stage IV represents distant metastases—most commonly to the liver parenchyma or lungs—confirmed by imaging or biopsy. Pleural effusions are not classified as Stage IV unless malignant cells are cytologically confirmed.

Accurate staging requires comprehensive surgical exploration—including total hysterectomy, bilateral salpingo-oophorectomy, omental resection, peritoneal biopsies, and systematic pelvic and para-aortic lymphadenectomy—particularly in postmenopausal patients or those with high-risk histologic subtypes (e.g., Sertoli–Leydig cell tumors with heterologous elements). In premenopausal women with fertility-sparing intent, unilateral salpingo-oophorectomy may be considered if disease is unequivocally Stage IA and low-grade, but thorough intraoperative assessment remains essential.

Notably, many sex cord–stromal tumors—especially adult granulosa cell tumors—exhibit indolent behavior and may recur years after initial diagnosis. Therefore, long-term surveillance is critical, regardless of initial stage. Staging informs both prognostic counseling and decisions regarding adjuvant therapy, though most early-stage cases require only surgical management.