Fibroblastic variant of low-grade endometrial stromal sarcoma mimicking an inflammatory pseudotumor: a case report

Abstract

The World Health Organization currently divides
endometrial stromal sarcomas into 4 different
entities, based on their clinical and pathological
features: endometrial stromal nodule, low-grade
endometrial stromal sarcomas (LG-ESS), Highgrade endometrial stromal sarcomas, and
undifferentiated uterine sarcoma. The fibroblastic
variant of LG-ESS is rare and is usually made of
small tumoral cells of oval to fusiform shape,
demonstrating low cytologic atypia and low
mitotic activity, which can lead to confusion with a
benign myofibroblastic proliferation. We hereby
report a rare case of a fibroblastic variant of LGESS in a 37-year-old woman presenting abundant
metrorrhagia, which was initially misdiagnosed
as an inflammatory pseudotumor before
proofreading in our laboratory, along with a
review of a histological and immunohistochemical
findings, aiming to