Incidence of lymph node and adnexal metastasis in endometrial stromal sarcoma

Objective: To determine the incidence of adnexal and lymph node (LN) metastasis in newly diagnosed endometrial stromal sarcoma (ESS).

Methods: We identified all cases with a diagnosis of ESS evaluated at our institution from January 1, 1980 to October 31, 2009. All uterine pathology was reviewed at our center. High-grade or undifferentiated tumors and ESS arising in extrauterine sites were excluded. Pertinent clinical data were abstracted from electronic medical records. Appropriate statistical tests were performed using SPSS16.0.

Results: We identified 94 cases of ESS. LN metastasis was identified in 7 (19%) of 36 patients who underwent LN evaluation. Six of the 7 cases with LN metastasis had lymphovascular invasion (LVI). LVI status was not reported in the other case. Five of the 7 patients with LN metastasis had grossly positive LNs with or without other gross extrauterine disease. Of 20 patients with disease grossly limited to the uterus and grossly normal LNs, 2 (10%) had LN metastasis. Both of these cases had LVI and extensive myoinvasion. Eighty-seven cases (93%) underwent salpingo-oophorectomy. Adnexal metastasis was identified in 11 (13%) of 87 cases, all manifested by gross adnexal tumor and occurring in patients with other gross pelvic extrauterine disease.

Conclusion: The incidence of LN metastasis in ESS is commonly associated with gross extrauterine disease, extensive myoinvasion, and LVI. Since myoinvasion and LVI status often are not assessable at the time of hysterectomy, LN dissection remains a reasonable option at primary surgery. The rate of adnexal metastasis appears to be negligible in the absence of gross adnexal and extrauterine tumor.