Endometrium and Myometrium Quiz

Endometrium and Myometrium

• Endometrium: The mucosal lining of the uterine cavity.
• Myometrium: The smooth muscle layer underneath the endometrium.
• Endometrium is hormone-sensitive.
  • Estrogen drives growth (proliferative phase).
  • Progesterone prepares for implantation (secretory phase).
  • Progesterone loss leads to shedding (menstrual phase).

Asherman Syndrome

• Secondary amenorrhea due to basalis loss and scarring.
• Often a consequence of aggressive dilation and curettage (D&C).

Anovulatory Cycle

• Lack of ovulation.
• Results in estrogen-driven proliferation without a subsequent progesterone-driven secretory phase.
• Leads to uterine bleeding due to proliferative gland breakdown and shedding.

Acute Endometritis

• Bacterial infection of the endometrium.
• Often caused by retained products of conception (e.g., after delivery or miscarriage).
• Symptoms include fever, abnormal uterine bleeding, and pelvic pain.

Chronic Endometritis

• Chronic inflammation of the endometrium.
• Characterized by lymphocytes and plasma cells.
• Causes include retained products, chronic pelvic inflammatory disease, IUDs, and tuberculosis.
• Symptoms include abnormal uterine bleeding, pain, and infertility.

Endometrial Polyp

• Hyperplastic protrusion of the endometrium.
• Often presents with abnormal uterine bleeding.
• Tamoxifen can cause endometrial polyps (it has weak pro-estrogenic effects on the endometrium, while being anti-estrogenic on the breast).

Endometriosis

• Endometrial glands and stroma outside the uterine lining.
• Often caused by retrograde menstruation and implantation at ectopic sites.
• Symptoms include dysmenorrhea and pelvic pain, potentially causing infertility.
• Endometriosis behaves like the normal endometrium with its cycle.
• Common sites of involvement include the ovaries (chocolate cysts), uterine ligaments, pelvic pain, pouch of Douglas, bladder wall, bowel serosa, and fallopian tubes.
• Involvement of the uterine myometrium is called adenomyosis.
• Risk of carcinoma may increase at endometriosis sites, particularly in the ovaries.

Endometrial Hyperplasia

• Increase in endometrial glands relative to stroma.
• Often occurs due to unopposed estrogen (e.g., obesity, polycystic ovary syndrome, estrogen replacement).
• Presents with postmenopausal bleeding
• Classified as simple or complex, with or without atypia.
• Atypia is a significant predictor of potential progression to carcinoma.

Endometrial Carcinoma

• Malignant growth of endometrial glands.
• Most common invasive carcinoma of the female genital tract.
• Often presents with postmenopausal bleeding.
• Can develop from hyperplasia or arise sporadically.
• Risk factors include early menarche, late menopause, nulliparity, infertility with anovulatory cycles, and obesity.
• Histology can be endometrioid or serous.

Leiomyoma (Fibroids)

• Benign smooth muscle tumors of the myometrium.
• Often multiple and common in premenopausal women and grow during pregnancy.
• Common symptoms include abnormal uterine bleeding, infertility, and pelvic mass.

Leiomyosarcoma

• Malignant smooth muscle tumors arising from the myometrium (not from leiomyomas).
• Typically found in postmenopausal women.
• Gross examination often reveals a single lesion with necrosis and hemorrhage.
• Histologically characterized by necrosis, mitotic activity, and cellular atypia.