Endometrial Stromal Sarcoma: Case Series with Emphasis on Gross Features

Endometrial stromal tumors: A clinico-histomorphological spectrum of endometrial stromal tumors with review of literature

BACKGROUND

Endometrial stromal tumors (ESTs) are rare subset of mesenchymal uterine neoplasms. There are heterogeneous morphological, immunohistochemical, and genetic features. Approximately 50% of ESTs occur in perimenopausal women. In 2020, WHO sub-categorized ESTs into four groups: endometrial stromal nodule (ESN), low-grade endometrial stromal sarcoma (LGESS), high-grade endometrial stromal sarcoma (HGESS), and undifferentiated uterine sarcoma (UUS).

OBJECTIVE

To review the morphological spectrum of endometrial stromal tumors.

METHOD

This retrospective study reviewed the histomorphological features of 15 endometrial stromal tumors with respect to atypia, necrosis, mitosis, collagen bands, whorling around vessels, myometrial invasion, and inflammatory cells. Immunohistochemistry markers (CD10, SMA, and ER) along with special stains (Masson's trichrome, toluidine blue) were also studied.

RESULTS

The age of the patients ranged from 32 to 60 years. Three patients were postmenopausal. The most common presenting symptom was vaginal bleeding. Five patients were operated with a clinical diagnosis of uterine fibroid. One patient presented with prolapse with no other complaint. All the 15 patients had total abdominal hysterectomy and salpingo-oophorectomy. One case showed necrosis, eight cases showed collagen bands, all the 15 cases showed whorling around vessels, one case showed vascular emboli, and seven cases showed inflammatory cells. In low-grade cases, one case showed focal atypia and one case showed focal coagulative necrosis indicating infarction. Thirteen cases were LGESS, and one case of ESN and HGESS. All cases were positive for ER and CD10.

CONCLUSION

Endometrial stromal tumors demonstrate extensive permeation of the myometrium as irregular islands with frequent vascular invasion, whorling around vessels, collagen bands, and inflammatory cells. All these features should be observed thoroughly on microscopy by pathologists to clearly differentiate the low-grade and high-grade endometrial stromal tumors, and to understand the overlapping gray areas morphologically as it affects the prognosis of the patient.

Case Series of Incidental Findings of Low-Grade Endometrial Stromal Sarcoma on Routine Hysterectomy for Uterine Fibroids

This study is a retrospective review of data from patients who were incidentally diagnosed with endometrial stromal sarcoma after a routine hysterectomy for uterine fibroid at the Department of Gynaecologic Oncology in a tertiary care hospital. The Institutional Review Board (IRB) gave its clearance for this study before it was carried out. Informed written consent was obtained from all patients. In our case series, the three patients presented with complaints of menorrhagia, lower abdominal pain, intermenstrual bleeding, and acute retention of urine. After the patients underwent a clinical examination and radiological scan, the diagnosis of fibroids was made. They underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy. Histology revealed low-grade endometrial stromal sarcoma (LGESS). The patients were observed for adjuvant therapy. The patients had a follow-up period of 18-24 months. In LGESS, which is rare, prompt management is of utmost importance, because the tumour's stage is the most significant predictor of the prognosis. As there are no clear indications to suggest the presence of LGESS prior to the histopathology of the specimen, it is necessary to analyze the data of patients who are diagnosed with LGESS, in order to investigate and manage the condition more appropriately. After myomectomy for a suspected leiomyoma, there is a 0.2% chance of the result showing endometrial stromal sarcoma.