Endometrial stromal tumours
- Lesion
Rare uterine tumours of the endometrial stroma; the border and the gene fusion decide whether they are benign, slow or aggressive.
What it is
Tumours of the endometrial stroma range from benign to highly aggressive. Adenosarcoma has benign glands in a malignant, usually low-grade, stroma. Among pure stromal tumours, the stromal nodule is well circumscribed and benign, low-grade endometrial stromal sarcoma permeates the myometrium and vessels in worm-like plugs and is driven by fusions such as JAZF1-SUZ12, high-grade stromal sarcoma carries YWHAE or BCOR alterations, and undifferentiated sarcoma has no recognisable line.
Structure
- Low-grade stromal sarcoma: tongues and plugs of uniform small cells permeating the myometrium and filling vessels, sometimes visible grossly as worm-like cords.
- Stromal nodule: the same cells forming a nodule with a smooth pushing border.
- Adenosarcoma: broad leaf-like fronds with glands compressed into slits and a cellular stroma condensed beneath their lining.
Step by step
- A translocation creates a fusion gene in an endometrial stromal cell (JAZF1-SUZ12 in many low-grade tumours).
- The fusion alters chromatin regulation and drives proliferation of cells that still look like normal stroma.
- A tumour that stays confined forms a nodule; one that invades spreads along vessels into the myometrium and beyond.
- Other fusions (YWHAE, BCOR) give high-grade tumours with faster growth and metastasis.
Markers
- CD10
- ER and PR
- Cyclin D1 and BCOR (high-grade)
- Fusion testing (FISH or sequencing)
Clinical notes
- Present with abnormal bleeding or an enlarged uterus; often diagnosed after hysterectomy for a presumed fibroid.
- Low-grade stromal sarcoma is hormone responsive and can recur many years later, including in the lung.
Test yourself
Think of the answer, then tap the question to see it.
What separates an endometrial stromal nodule from a low-grade stromal sarcoma?
The border: the nodule is well circumscribed, while the sarcoma permeates the myometrium and lymphovascular spaces.
Which gene fusion is typical of low-grade endometrial stromal sarcoma?
JAZF1-SUZ12, from a t(7;17) translocation.
What is periglandular cuffing?
Condensation of cellular malignant stroma around benign glands, typical of adenosarcoma.
Elsewhere in DurgiPedia
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Uterine Sarcoma Treatment (PDQ®)–Health Professional Version (National Cancer Institute, 2026).
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Representative model, for educational purposes only.