endometrial stromal sarcoma

PO

Definition: ESS shows ovoid cells with scattered hyperchromatism, and numerous mitotic figures. It is invasive and likely to show lymphovascular invasion. It is CD10 positive, differentiating the lesion from leiomyosarcoma. Endometrial stromal sarcoma has CD10 positive malignant cells and is invasive.

Images

 low-grade Endometrial Stromal Sarcoma (LG-ESS)

• https://twitter.com/A_Elshaikh/status/817565805332361218

 ESS metastatic to colon

• https://twitter.com/KristenStashek/status/877954811601108995

Microscopy

 The microscopy shows ovoid cells with scattered hyperchromatism, and numerous mitotic figures, including atypical mitoses.
 It is invasive and likely to show lymphovascular invasion.

Immunochemistry

It is CD10 positive, differentiating the lesion from leiomyosarcoma.

 SMM-HC+ (smooth muscle myosin heavy chain)
 calponin+

 CD10+

• CD10+ in endometrial stromal tumors (ESTs) / endometrial stromal sarcoma (ESS) / endometrial stromal nodule (ESN)
• CD10 have a positive staining in a small number of endometrial stromal sarcomas as well as in normal endometrial stroma.
• CD10 is a reliable and sensitive immunohistochemical marker of normal endometrial stroma.
• Positivity, which is often strong and/or diffuse is found in endometrial stromal nodules and low-grade ESS. (11532038)
• Positive staining with CD10, when strong and diffuse, may be useful in distinguishing these tumours from histological mimics, especially cellular leiomyoma and AGCT which are generally negative.
• CD10 should be used as part of a panel which might include desmin and alpha-inhibin depending on the differential diagnosis considered.
• Positive staining with CD10 in a high-grade uterine sarcoma which is negative with muscle markers might indicate endometrial stromal differentiation and identify a group of neoplasms which it is correct to diagnose as high-grade ESS rather than undifferentiated uterine sarcoma. (11532038)

Subtypes

 high-grade endometrial stromal sarcoma

DIfferential diagnosis

See: uterine spindle cell tumors

Endometrial stromal tumors may pose diagnostic challenges particularly when they exhibit variant histologic appearances, involve extrauterine sites, or present as metastatic disease. In such cases, use of immunohistochemical markers and identification of specific nonrandom chromosomal rearrangements may be helpful.

 endometrial stromal nodule

• Stromal nodule does not have atypical mitoses, and has a lower number of mitosis.

 uterine leiomyoma

• Classic leiomyoma is not this atypical or cellular (variants of leiomyoma include cellular leiomyoma and atypical leiomyoma).
• Leiomyoma is not CD10 positive.

 uterine leiomyosarcoma

• Leiomyosarcoma is not CD10 positive.

Molecular biology

 JAZF1-JJAZ1 fusion gene

• fusion genes between JAZF1 at 7p15 and JJAZ1 at 17q21 by t(7;17)(p15;q21) (12850374, 11371647)

 NUTM2-YWHAE fusion gene in high-grade endometrial stromal sarcoma (YWHAE-NUTM2 )
 BCOR-ZC3H7B fusion gene in high-grade endometrial stromal sarcoma (ZC3H7B-BCOR ) (27631520)

Cytogenetics

 t(3;6)(q29;p21.1) (14580778)
 t(7;17)(p15;q21) (JAZF1-JJAZ1 fusion gene)
 t(10;17)(q22;p13) (14529693)
 t(X;17)(p11:q23)

Differential diagnosis

 endometrial stromal tumors

• benign stromal nodule
• undifferentiated endometrial sarcoma

 uterine smooth muscle tumors

• cellular uterine leiomyoma
• uterine leiomosarcoma

See also

 extrauterine endometrial stromal sarcoma

References

 Endometrial Stromal Sarcomas With Sex Cord Differentiation Are Associated With PHF1 Rearrangement. D’Angelo E, Ali RH, Espinosa I, Lee CH, Huntsman DG, Gilks B, Prat J. Am J Surg Pathol. 2012 Dec 1. PMID: 23211293