Female Anatomy: Ovaries and Menstruation

Ovaries

• Paired ovoid structures, each weighing 5-8g, situated in the retrouterine space
• Germinal epithelium covers each ovary except where attached to the broad ligament of the uterus
• Bulk consists of dense mesenchymal ovarian stromal cells and germinal follicles
• Corpora lutea present after puberty at various stages of maturation
• Appearance depends on age and menstrual cycle phase
• Closer to menarche, more primordial follicles
• Closer to menopause, more regressed, hyalinized corpora lutea (corpora albicantia)
• In prepubertal females the ovaries are small and mainly consist of stroma and primordial germ cells
• At birth, ovaries possess the full complement of germ cells needed for the entire reproductive life
• The uterus is small before puberty and is lined by inactive thin endometrium

Menstruation and Hormones

• Menarche (onset of menstruation) signifies the onset of puberty in females (10-14 years)
• Pituitary secretion of follicle-stimulating hormone (FSH) dictates menstruation
• The hypothalamus controls FSH secretion via gonadotropin-releasing hormones
• FSH secretion is primarily controlled by feedback from ovarian hormones after initial hypothalamus stimulation, kickstarting cyclic menstruation

Menopause

• Marks the end of reproductive life through the cessation of menstruation
• Caused by the primary failure of the ovary to respond to FSH stimulation
• Characterized by failure of ovulation, marked decrease in estrogen, absence of progesterone secretion, atrophy of the endometrium, and a marked increase in pituitary FSH secretion
• Elevated FSH causes symptoms include hot flushes

Manifestations of Ovarian Disease

• Failure of ovarian function can manifest as infertility
• Infertility is due to failure of ovulation
• Can manifest as menstrual irregularities caused by abnormal patterns of ovarian hormone secretion
• Ovarian diseases categories include neoplastic and non-neoplastic

Ovarian Cysts

• Physiologically normal ovarian structures (follicles, corpora lutea) can enlarge or become cystic, resembling a neoplastic lesion
• Follicular cysts are 1-5 cm in diameter and are lined by flattened granulosa cells
• Luteal cysts and hematomas occur because of the degeneration of the corpus luteum
• Theca lutein cysts are multiple cysts occurring in patients with trophoblastic neoplasms that secrete human chorionic gonadotropin (hCG)

Polycystic Ovary Syndrome (PCOS)

• Characterized by bilaterally enlarged ovaries and multiple follicular cysts in outer, subcapsular region
• Absence of corpora lutea occurs (resulting from failure of ovulation)
• Manifests as hyperplastic ovarian stroma with thickening of the capsule
• Associates with amenorrhea, infertility, and virilism (Stein-Leventhal syndrome)
• Excess androgen, usually androstenedione is secreted
• Normal or elevated estrogen levels result in endometrial hyperplasia and abnormal uterine bleeding (menorrhagia)
• There is an increased incidence of endometrial carcinoma
• The cause is likely an abnormal pituitary gonadotropin secretion
• The normal luteinizing hormone (LH) surge is absent, continuous FSH and LH stimulation leads to developing multiple follicular cysts
• Clomiphene stimulates ovulation and is an effective treatment
• Surgical wedge resection of the ovary was a standard treatment but is rarely needed now

Ovarian Cancer

• The second most frequent gynecological malignancy after endometrial cancer
• Neoplasms of the ovary are relatively common with 75–80% being benign
• Malignant ovarian neoplasms account for about 5% of all cancers in women
• Benign neoplasms occur in a younger age group (20–40 years)
• Malignant ones occur in an older age group (40–60 years), but there is considerable overlap
• Causes poorly defined and risk factors are poorly defined

Risk Factors for Ovarian Cancer

• Nulliparity
• Genetic Factors:
  • Mutations of BRCA1 and BRCA2 suppressor genes
  • Lynch syndrome
  • Turner's syndrome
  • Peutz-Jeghers syndrome
• Smoking cigarettes
• OCPs decrease the risk
  • Decreased number of ovulatory cycles

Ovarian Cancer Clinical Findings

• Signs of seeding from malignant surface-derived cancers
  • Malignant ascites and increased abdominal girth
  • Induration in the rectal pouch on digital rectal examination
  • Intestinal obstruction with colicky pain
• Palpable ovarian mass in a postmenopausal woman
  • Ovaries should not be palpable in menopausal women
• Malignant pleural effusion can occur with ovarian cancer metastasis
• Cystic teratomas undergo torsion leading to infarction
  • Radiographs show calcification from bone or teeth
• Estrogen-secreting tumors has signs of hyperestrinism -Bleeding from endometrial hyperplasia/cancer
  • 100% superficial squamous cells in a cervical Pap smear
• Androgen-secreting tumors exhibits hirsutism or virilization

Ovarian Cancer Lab Findings

• Tumor markers show increased serum cancer antigen 125 (CA 125)
  • increased in surface-derived malignant tumors
• USS
• Diagnostic cytology results show peritoneal washing
• Histology shows results of an ovarian biopsy obtained by either laparotomy or surgical culdoscopy
• Molecular genetic (Cytogenetic) testing

Prognosis Factors for Ovarian Cancer

• Younger patients have a better outcome
• BRCA1 mutations and family history lead to a favorable clinical course
• Presence and extent of tumor spread beyond the ovary
• Ascites
• Borderline tumors versus carcinomas
• Tumor grade and type
• Psammoma bodies
• Rupture of tumor capsule
• DNA ploidy
• CA-125 present
• p53 Overexpression
• Tumor angiogenesis
• Intratumoral T cells
• Overexpression of HER2/neu, EGFR, fatty acid synthase (OA-519), nm23, P-glycoprotein, CD24, S100A1 also contribute

Classification of Ovarian Tumors

• Classified according to histogenesis
  • Surface epithelium derived from the coelomic epithelium
  • Germ cells that migrate to the ovary from the yolk sac and are pluripotent
  • Stroma of the ovary, including the sex cords which are forerunners of the endocrine apparatus of the postnatal ovary
  • Metastases

Fallopian Tubes

• The fallopian tube (salpinx) is a tubular hollow structure that measures 11–12 cm
• Spans the distance from the uterine cornu to the ovary throughout the broad ligament apex
• Four segments: intramural (inside the uterine wall), isthmus (2–3 cm, thick-walled), ampulla (thin-walled expanded area), and infundibulum(trumpet-shaped ending that opens into the peritoneal cavity through the ostium and is fringed by the fimbriae)
• One of the latter structures, known as the ovarian fimbria, attaches the tube to the ovary
• Disorders include infections leading to inflammatory conditions and ectopic (tubal) pregnancy

Inflammatory Conditions of Fallopian Tubes

• Suppurative salpingitis may be caused by pyogenic organisms
• Gonococcus accounts for 60% of suppurative salpingitis cases, with chlamydiae less often a factor
• Tubal infections are a part of pelvic inflammatory disease
• Tuberculous salpingitis is common in Nigeria and other parts of the world where tuberculosis is prevalent
• Tuberculosis is an important cause of infertility in those areas

Tubal Ectopic Pregnancy

• The incidence of tubal pregnancy (eccyesis) has increased markedly in recent times
• It can result from chronic salpingitis, which causes destruction to the inflammatory lining folds and retention of the ovum
• There is an increased risk of tubal pregnancy with a history of infertility
• Gestation occurs outside the normal uterine location with the majority occurring in the tubes, in the broad ampullary portion below the fimbriae
• Other sites include ovaries and the abdominal cavity
• Scarring from previous PID and endometriosis, and altered tubal motility are causes
• Clinical findings Sudden onset of lower abdominal pain -Usually ~6 weeks after a previous normal menstrual period Abnormal uterine bleeding, adnexal mass, and hypovolemic shock
• Complications arise with Rupture with intra-abdominal bleed (Most common cause of death in early pregnancy) and hematosalpinx (Blood in the tube)

Diagnosing Tubal Ectopic Pregnancy

• Beta-hCG is the best screening test as a Urine screen is usually sensitive enough
• Serum test is used if the urine screen is negative
• Positive test does not prove that ectopic pregnancy is present
• Vaginal ultrasound is the confirmatory test where you can check for an amniotic sac
• Laparoscopy is used in equivocal cases
• The gestational sac is completely made up of tubal tissue, with no participation from the ovarian or intraligamentary tissues
• Following ovum implantation in the tubal epithelium (usually in the ampullo-isthmic or midtubal portion), chorionic villi and extravillous (intermediate) trophoblasts can grow predominantly intraluminally or penetrate into the wall just as they do in the uterus