Page 751 - Textbook of Pathology, 6th Edition

TUMOURS OF ENDOMETRIUM AND MYOMETRIUM ETIOPATHOGENESIS. The exact etiology of endometrial 735
cancer remains unknown. However, a few factors associated
Tumours arising from endometrium and myometrium may with increased frequency of its development are chronic
be benign or malignant. They may originate from different unopposed oestrogen excess, obesity, diabetes, hypertension
tissues as under: and nulliparous state. There is irrefutable evidence of
Endometrial glands—endometrial polyps, endometrial
carcinoma. relationship of endometrial carcinoma with prolonged oestrogenic
stimulation. These evidences are as under:
Endometrial stroma—stromal nodules, stromal sarcoma. 1. Endometrial carcinoma has association with endometrial
Smooth muscle of the myometrium—leiomyoma, hyperplasia (discussed above) in which there is unopposed
leiomyosarcoma. chronic hyperoestrogenism and frequent anovulatory cycles.
Mullerian mesoderm—mixed mesodermal or mullerian 2. In postmenopausal years when endometrial carcinoma
tumours. occurs characteristically, there is excessive synthesis of
Out of these, endometrial polyps, endometrial carcinoma, oestrogen in the body from adrenal as well as from ovarian
leiomyomas and leiomyosarcomas are relatively more sources.
common and are described below. 3. Women having oestrogen-secreting tumours (e.g. granu-
losa cell tumour) have increased risk of developing
Endometrial Polyps synchronous endometrial cancer.

‘Uterine polyp’ is clinical term used for a polypoid growth 4. Patients receiving prolonged exogenous oestrogen
projecting into the uterine lumen and may be composed of therapy are at higher risk of developing this cancer.
benign lesions (e.g. endometrial or mucous polyp, 5. Women of breast cancer receiving tamoxifen for prolonged
leiomyomatous polyp and placental polyp), or malignant period have 2-fold increased risk of developing uterine
polypoid tumours (e.g. endometrial carcinoma, choriocar- cancer.
cinoma and sarcoma). The most common variety, however, 6. Prolonged administration of oestrogen to laboratory
is the one having the structure like that of endometrium and animals can produce endometrial hyperplasia and
is termed endometrial or mucus polyp. They are more common carcinoma.
in the perimenopausal age group. Small endometrial polyps 7. Women with gonadal agenesis rarely develop endo- CHAPTER 24
generally remain asymptomatic and are detected metrial carcinoma.
incidentally. The larger ones may ulcerate, degenerate and Pathogenetically, papillary serous variant of endometrial
result in clinical bleeding. carcinoma is associated with mutation in p53 tumour
suppressor gene while endometrioid carcinoma has mutation
MORPHOLOGIC FEATURES. Grossly, endometrial in PTEN gene located on chromosome 10. The role of heredity
polyps may be single or multiple, usually sessile and small in pathogenesis of endometrial cancer is supported by higher
(0.5 to 3 cm in diameter) but occasionally they are large incidence in hereditary non-polyposis colon cancer (HNPCC)
and pedunculated. syndrome (having simultaneous cancers of the colon and
Histologically, they are essentially made up of mixture endometrioid adenocarcinoma) and in Cowden syndrome
of endometrial glands and stroma. The histologic pattern (having simultaneous cancers of the breast, thyroid, and
of the endometrial tissue in the polyp may resemble either endometrium). The Female Genital Tract
functioning endometrium or hyperplastic endometrium
of cystic hyperplasia type, the latter being more common. MORPHOLOGIC FEATURES. Grossly, endometrial
Rarely, a large endometrial polyp may undergo malignant carcinoma may have 2 patterns—localised polypoid tumour,
change. or a diffuse tumour; the latter being more common
(Fig. 24.14). The tumour protrudes into the endometrial
Endometrial Carcinoma cavity as irregular, friable and grey-tan mass. Extension
Carcinoma of the endometrium, commonly called uterine of the growth into the myometrium may be identified by
cancer, is the most common pelvic malignancy in females in the presence of soft, friable and granular tissue in cut
the United States and Eastern Europe but is uncommon in section. In advanced disease, the involvement may extend
Asia where cervical cancer continues to be the leading cancer beyond the physiologic limits—into the cervical canal, into
in women. Whereas the decline in the incidence of cervical the peritoneum, besides lymphatic metastases and
cancer in the developed countries is due to aggressive cervical haematogenous metastases to distant sites such as lungs,
screening programme leading to early detection and cure of liver, bones and other organs.
in situ stage, increased frequency of endometrial carcinoma Histologically, most endometrial carcinomas are
in these countries may be due to longevity of women’s life adenocarcinomas, commonly termed endometrioid
to develop this cancer of older females. It is primarily a adenocarcinomas due to their resemblance with normal
disease of postmenopausal women, the peak incidence at endometrium. Depending upon the pattern of glands and
onset being 6th to 7th decades of life and is uncommon below individual cell changes, these may be well-differentiated,
the age of 40 years. The most important presenting complaint moderately-differentiated or poorly-differentiated.
is abnormal bleeding in postmenopausal woman or excessive Well-differentiated adenocarcinoma is characterised by
flow in the premenopausal years. increase in the number of glands which are closely packed