Introduction: Endometrial stromal tumor is a rare mesenchymal uterine tumor. Endometriosis, an affection of the women during her fertile period, is reported in the pertinent literature to have an incidence varying from 1% to 53%, which shows a wide difference from one study to another. The pathology that grafts onto the endometriosis foci is rare, and the malignant tumoral pathology is extremely rare. The most frequent malignant tumors quoted in the pertinent literature are of the adenocarcinoma type, on the endometriosis, and the alterations of the sarcomatous type can appear extremely rarely. Most sarcomas appear on the foci of the rectosigmoid endometriosis. These rare tumors should not be taken for the mesenchymal gastrointestinal tumors. The recurrence of the malignant alterations of the endometriosis foci is estimated at about 0.7-1% in the pertinent literature.
Materials and methods: We are presenting a case of endometrial stromal sarcoma, developed on foci of outer endometriosis (sigmoid and appendicular endometriosis), diagnosed in our laboratory on two operatory pieces taken from the same woman, at a 2-month interval. The macroscopic and microscopic study was done on operatory pieces, with the routine procedure, macroscopic examination, fixing in 10% formalin, embedding in paraffin and staining with Hematoxylin-Eosin and than we used immunohistochemical markers, for endometrial stroma.
Results: The endometrial stromal sarcoma developed on foci of endometriosis is very rare, has an incidence of 6% within the endometrial malignant tumors, with various degrees of malignancy, low malignancy, or high malignancy.
Conclusions: We do not exclude the appearance of the endometrial sarcoma on the outer endometriosis foci. Moreover, the endometriosis foci can be considered as pre-malignant conditions.