[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Female genital tract](https://durgical.com/en/general-pathology/areas/female-genital/) › Endometrial stromal tumours

# 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.

Updated Nov 12, 2026

## Key points

- Adenosarcoma: polypoid mass; leaf-like benign glands with stroma condensed around them (periglandular cuffing); recurs locally.
- Stromal nodule vs low-grade stromal sarcoma: same cells, but the sarcoma infiltrates the myometrium and lymphovascular spaces.
- Low-grade stromal sarcoma: cells like proliferative-phase stroma around small arterioles; CD10, ER and PR positive; JAZF1-SUZ12 fusion; indolent, late recurrences.
- High-grade stromal sarcoma: YWHAE-NUTM2 or BCOR fusions, aggressive.
- Undifferentiated uterine sarcoma: marked atypia, no specific differentiation, very poor prognosis.

## 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.

## Memory aid

The stromal nodule stays behind its fence; the low-grade sarcoma crawls through the vessels like worms.

## 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.

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## Elsewhere in DurgiPedia

- [FISH (fluorescence in situ hybridization)](https://durgical.com/en/biochemistry/topics/fish/)

## Connections

## Related 5

- [Uterine leiomyosarcoma vs leiomyoma](https://durgical.com/en/general-pathology/uterine-leiomyosarcoma-vs-leiomyoma/)
- [High-grade endometrial cancers: serous, clear cell, carcinosarcoma](https://durgical.com/en/general-pathology/high-grade-endometrial-cancers-serous-clear-cell-carcinosarcoma/)
- [Uterine leiomyoma](https://durgical.com/en/general-pathology/uterine-leiomyoma/)
- [Translocations, amplifications and epigenetic changes in cancer](https://durgical.com/en/general-pathology/translocations-amplifications-and-epigenetic-changes-in-cancer/)
- [Benign vs malignant tumours: the comparison table](https://durgical.com/en/general-pathology/benign-vs-malignant-tumours-the-comparison-table/)

## Related conditions 2

- [Soft tissue sarcomas (liposarcoma, leiomyosarcoma, rhabdomyosarcoma)](https://durgical.com/en/conditions/soft-tissue-sarcomas/)
- [Abnormal uterine bleeding](https://durgical.com/en/conditions/abnormal-uterine-bleeding/)

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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](https://www.cancer.gov/types/uterine/hp/uterine-sarcoma-treatment-pdq) (National Cancer Institute, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/general-pathology/endometrial-stromal-tumours/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/endometrial-stromal-tumours/