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Chapter 45 Uterine Sarcomas
Maria A. Suescum, MD and
Justin Chura, MD, MBA❍ What is the incidence of uterine sarcomas?
Sarcomas account for 3% to 8% of all uterine malignancies. The annual incidence is approximately 2 cases per
100,000 women.
❍ Define the following terms that Ober used to classify uterine sarcomas according to cell type and origin.
Pure/Mixed.
Homologous/Heterologous.
Pure sarcoma—Virtually all are homologous coming from mesenchymal type cells.
Mixed—More than one cell type present, usually malignant mesenchymal and epithelial elements.
Homologous—Cell types are indigenous to the uterus (ie, leiomyosarcoma, stromal sarcoma, and angiosarcoma).
Heterologous—Cell types are foreign to the uterus (ie, rhabdomyosarcoma, chondrosarcoma, and osteosarcoma).
❍ List the four major groups of uterine sarcomas by decreasing incidence.
Carcinosarcomas (previously known as MMMT)—50%.
Leiomyosarcoma—40%.
Endometrial stromal sarcoma (ESS)—8%.
Adenosarcoma—<2%.
❍ Prior pelvic irradiation is associated with the development of which type of uterine sarcoma?
Approximately 10% of patients with carcinosarcoma have a prior history of pelvic irradiation.
❍ What histologic criteria are used when diagnosing a benign endometrial stromal nodule?
Endometrial stromal nodules are characterized by a proliferation of uniform, normal-appearing stromal cells with
a well-circumscribed, noninfiltrative margin. Lymphvascular space involvement is absent, and the mitotic count is
usually <5 per 10 high-power fields.