Endometrial stromal sarcoma is rare in gastrointestinal and other sites of malignant transformation of endometriosis.
The differential diagnosis of endometrial stromal sarcoma arising in the gastrointestinal tract includes mesenchymal neoplasms, particularly if the underlying benign endometriosis is obscured.
Rabban and coworkers (8) detected no ALK-1 staining among 7 uterine leiomyomas, 6 uterine leiomyosarcomas, 4 uterine carcinosarcomas, 4 endometrial stromal sarcomas
, and 1 uterine lymphangiomyomatosis.
1,2) Recurrent cases of low-grade endometrial stromal sarcoma (ESS) are especially rare.
Styron SL, Burke TW, Linville WK: Low-grade endometrial stromal sarcoma recurring over three decades.
The tumors of one group are morphologically similar to low-grade endometrial stromal sarcomas
with diffuse HMB-45 expression and focal expression of smooth muscle markers.
If glands within the adenomyotic foci are sparse, the differential diagnosis with low-grade endometrial stromal sarcoma
should be raised, (21) whereas an excess of glands might suggest the possibility of an endometrial hyperplasia or carcinoma extending into (or even arising within) foci of adenomyosis.
The results showed that PD-1/PD-L1 were most often co-expressed in endometrial stromal sarcomas
and endometrioid endometrial cancer, while lower expression rates were detected in human papilloma virus (HPV)-associated cancers of the lower gynecologic tract.