Endometrial Stromal Tumors

Transcription

1 Endometrial Stromal Tumors WHO Categories: Endometrial Stromal Nodule (ESN) Endometrial Stromal Sarcoma, low grade (LGESS) Endometrial Stromal Sarcoma, high grade (HGESS) Undifferentiated Uterine Sarcoma (UUS)

2 Endometrial Stromal Sarcoma, low grade Epidemiology: Rare, <1% of all uterine malignancies Second most common malignant mesenchymal uterine tumor Wide age range (mean age 52 years) Clinical features: Abnormal uterine bleeding or abdominal pain Pelvic mass Asymptomatic Metastasis (ovary, lung) Source: Sternberg s Diagnostic Surgical Pathology, 6th Edition

3 Int J Gynecol Cancer 2016;26: Results: 3021 patients underwent total hysterectomy for presumed leiomyoma - 18 (1/168, 0.60%) had unexpected uterine sarcoma - 5 (1/604, 0.17%) leiomyosarcoma - 13 (1/232, 0.43%) low-grade endometrial stromal sarcoma

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5 Endometrial Stromal Nodule Def.: Benign Well-circumscribed Cells: resemble proliferative-phase endometrial stroma. Minimal myometrial invasion: < 3mm, < 3 protrusions No lymphovascular invasion

6 Endometrial Stromal Nodule Source: Sternberg s Diagnostic Surgical Pathology, 6th Edition

7 Endometrial Stromal Nodule Recognition as an Endometrial Stromal Neoplasm (Biopsy/Curettage) DD: aglandular functionalis Atrophic endometrial stroma Distinction from low grade Endometrial Stromal Sarcoma (Biopsy/Curettage) Cannot be made with certainty in most cases. «endometrial stromal neoplasia» Presence of lymphovascular invasion allows for diagnosis of LGESS.

8 Endometrial Stromal Nodule Distinction from LGESS (hysterectomy) Extensive sampling of the border of the tumor is imperative < 3 mm invasion, < 3 protrusions Distinction from Highly Cellular Leiomyoma Large, thick-walled vessels throughout tumor in Leiomyoma. Cleft-like spaces. Merging of fascicles at the periphery with the myometrium. Immunohistochemistry: ESN HCL CD10 pos neg (pos) Desmin pos/neg pos h-caldesmon neg (pos) pos

9 Endometrial Stromal Sarcoma, low grade Macroscopy: Multiple, poorly defined, tan to yellow, soft nodules within endo- and myometrium. Histology: Extensive permeation of myometrium (tongue-like, finger-like, worm-like plugs) Vascular invasion Cells: resemble proliferative-phase endometrial stroma Rich vascular background (resembling spiral arterioles) Cells growing in swirling pattern around vessels Mitotic activity low (<10/10 HPF)

10 Endometrial Stromal Sarcoma, low grade Source: Sternberg s Diagnostic Surgical Pathology, 6th Edition

11 Endometrial Stromal Sarcoma, low grade Variant morphology Smooth muscle differentiation (with central hyalinization) Sex cord-like differentiation (granulosa and Sertoli cells) Fibromyoid change Endometrioid-type glands Rarely: skeletal muscle diff., epithelioid or clear cell change, adipocytic diff., pseudopapillary appearance, multinucleated giant cells.

12 Endometrial Stromal Sarcoma, low grade Distinction from Highly Cellular Intravenous Leiomyomatosis Clefted and lobulated contour Fascicular growth Nuclei with blunted ends Prominent thick-walled vessels Immunhistochemie LGESS IVL CD10 pos neg (pos) Desmin pos/neg pos h-caldesmon neg (pos) pos

13 Endometrial Stromal Sarcoma, low grade Distinction from high grade Endometrial Stromal Sarcoma Poorly circumscribed, diffuse myometrial invasion, often advanced stage Hemorrhage and necrosis often present Both high grade and low grade areas High grade features: Hypercellularity Round, uniform cells with granular to vesicular cytoplasm, irregular nuclear contours and distinct nucleoli Mitotic activity >10/10 HPF Vascular pattern: delicate and arborized

14 Endometrial Stromal Sarcoma, high grade Source: Sternberg s Diagnostic Surgical Pathology, 6th Edition

15 Endometrial Stromal Sarcoma, low grade Distinction from high grade Stromal Sarcoma Immunohistochemistry LGESS HGESS CD10 pos neg ER pos neg PR pos neg Cyclin D1 weak pos strong pos CD117 neg pos