Tumors of the Endometrium with Stromal Differentiation

A proportion of endometrial adenocarcinomas undergo stromal differentiation and are termed carcinosarcomas. A second group is composed of stromal neoplasias in association with

benign glands (adenosarcomas). A third group consists of pure stromal neoplasms, ranging from benign (stromal nodule) to malignant (stromal sarcoma). Together, these tumors comprise

less than 5% of endometrial cancers.

CARCINOSARCOMAS

Carcinosarcomas (formerly termed malignant mixed müllerian tumors) consist of endometrial adenocarcinomas in which malignant stromal differentiation takes place.[85] The stroma tends

to differentiate into a variety of malignant mesodermal components, including muscle, cartilage, and even osteoid. The epithelial and stromal components are presumably derived from the

same cell, a concept supported by the observation that the stromal cells often stain positive for epithelial cell markers. Carcinosarcomas occur in postmenopausal women and manifest,

similarly to adenocarcinoma, with postmenopausal bleeding. Many affected patients give a history of previous radiation therapy.

Morphology.

In gross appearance, such tumors are somewhat more fleshy than adenocarcinomas, may be bulky and polypoid, and sometimes protrude through the cervical os. On histology, the tumors

consist of adenocarcinoma mixed with the stromal (sarcoma) elements ( Fig. 22-33A ); alternatively, the tumor may contain two distinct and separate epithelial and mesenchymal

components. Sarcomatous components may mimic extrauterine tissues (i.e., striated muscle cells, cartilage, adipose tissue, and bone).

Outcome is determined primarily by depth of invasion and stage. As with endometrial carcinomas, the prognosis may be influenced by the grade and type of the adenocarcinoma, being

poorest with serous differentiation. It is noteworthy that carcinosarcomas usually metastasize as adenocarcinomas. The tumors are highly malignant, and patients have a 5-year survival rate

of 25% to 30%.[85]

Figure 22-33 A, Carcinosarcoma, showing both epithelial (upper right) and stromal (arrow) differentiation. B, Endometrial stromal sarcoma infiltrating myometrium. C, Fluorescent in situ

hybridization using two fluorescently labeled probes (green and red) that flank the breakpoint of the gene involved in the chromosomal translocation t(7;17) in endometrial stromal

sarcoma. The yellow signal is indicative of the normal copy of chromosome 7. A separate green and red signal indicates that the gene on chromosome 7 has been redistributed. (Courtesy of

Dr. Marisa R. Nucci, Brigham and Women's Hospital, Boston, MA.)

Figure 22-34 A, Leiomyomas of the myometrium. The uterus is opened to reveal the tumors bulging into the endometrial cavity and displaying a firm white appearance on sectioning. B,

Leiomyoma showing well-differentiated, regular, spindle-shaped smooth muscle cells.

Figure 22-35Leiomyosarcoma. A, A large hemorrhagic tumor mass distends the lower corpus and is flanked by two leiomyomas. B, The tumor cells are irregular in size and have

hyperchromatic nuclei.

Figure 22-36Polycystic ovarian disease and cortical stromal hyperplasia. A, The ovarian cortex reveals numerous clear cysts. B, Sectioning of the cortex reveals several subcortical cystic

follicles. C, Cystic follicles seen in a low-power microphotograph. D, Cortical stromal hyperplasia manifests as diffuse stromal proliferation with symmetrical enlargement of the ovary.

TABLE 22-3-- Ovarian Neoplasms (1993 WHO Classification)

Date: 2016-04-22; view: 681