ESS are very rare malignant tumors that make up approximately 10% of all uterine sarcomas but only around 0.2% of all uterine malignancies .
ESS are divided in low and high-grade tumors according to cell morphology and mitotic count , Boardman CH, et al defined low-grade ESS from high-grade ESS by the cellular uniformity, less frequent mitosis (<3 per 10 high-power fields versus >10), and lack of hemorrhage and necrosis . However, there are controversies surrounding the separation of endometrial stromal sarcomas into high and low grade based on mitotic activity and at present, mitotic counts are no longer used to differentiated high-grade from low-grade lesions . Accordingly, several authors have concluded that two separate disease entities exist and, respectively, that HGESS should be regarded as an undifferentiated sarcoma or as a unique type of high-grade uterine sarcoma (e.g. carcinosarcoma without any detectable carcinoma portion) .
Low-grade endometrial stromal sarcoma (LGESS) has an infiltrating margin and typically shows extensive worm-like vessel invasion .
Most patients are in the age range of 42 to 53 years. More than half the patients are premenopausal. Young women and girls may be affected. In this study, 79% of patients were premenopausal.
Abnormal vaginal bleeding is the most common presenting symptom, and abdominal pain and uterine enlargement may occur [9, 7]. We showed abnormal vaginal bleeding in 86% of the patients. Clinical impression in four cases was uterine myoma (28.5%) and one patient had presented with severe abdominal pain.
The median follow-up time was 45.6 months (range 24–84). Five-year survival rate was 93%. In this study, the median overall survival of the 14 patients was 45.35 ± 21 months (range 20–83).
Although the bulk of the tumor is almost always intramyometrial , most endometrial stromal sarcomas involve the endometrium, and uterine curettage usually leads to diagnosis . In our study, the diagnosis in four patients (28.5%) was made through D&C. The other 10 patients were diagnosed by hysterectomy (71%). Surgery has always been described as the most effective treatment in LGESS as other uterine sarcomas. Primary surgery was performed in 13 patients in our series. The one patient refused from any treatment such as surgery.
The efficacy of adjuvant therapy in patients with ESS is still not proven . In our study radiotherapy as adjuvant, therapy was administered to four patients (28.5%), but one of them recurred at 9 months.
Although LGESS behavior is relatively indolent, late recurrence and distant metastases may occur . The risk of recurrence is thought to be as high as 50%, although these tumors are usually slow growing and recurrences occur late. In one large series, the interval before recurrence varied from 3 months to 23 years, with a median interval of 3 years. In the largest clinico-pathologic study to date on ESS, the median time between hysterectomy and relapse was 5.4 years and 9 month for stages 1 and 3–4, respectively . We showed only one recurrence at 9 months, but two recurrences occurred at 6 and 8 years respectively.
In Brunisholza study, the recurrent disease mainly spread to the pelvis, lower genital tract, lungs, and rarely to other site . Recurrence sites in our patients were vagina, pelvis, and lung.
Prolonged survival and even cure are common after surgical resection of recurrent or matastatic lesions . One of our patients is alive 3 years without disease after resection of vaginal metastasis and chemotherapy.
Uterine sarcomas have a poor prognosis, and survival is much worse than that reported for endometrial adenocarcinoma, with an overall survival of less than 50% at 2 years, even when presenting at an early stage . A higher survival probability for patients with LGESS compared to other uterine sarcoma is often reported . In this study, five-year survival rate was 93%.
Prognostic factors in patients with ESS are still discussed controversially . The negative prognostic influence of a high mitotic count was revealed in previous studies . In the present study, survival probabilities were calculated by the product limit method of Kaplan and Meier that showed, patients with no myometrial invasion and low mitotic count <= 5/HPF have longer disease-free survival, but P value was not significant.