Pathology

Pathology/C/75

Ovarian tumors

卵巣腫瘍

1. Overview

  • Highest mortality among gynecologic malignancies.
  • Diverse pathologic entities due to 3 cell types in the normal ovary.

Three Main Categories

  1. Surface epithelial tumors (benign / borderline / malignant)
  2. Germ cell tumors
  3. Sex cord–stromal tumors

Pathogenesis & Risk Factors

  • Nulliparity, unmarried women, family history.
  • 5–10 % familial — BRCA1 / BRCA2 mutations.
  • Other: ↑ ovulatory cycles (early menarche, late menopause), HRT, smoking.

Symptoms

  • Abdominal mass + pain + distention (ascites).
  • Estrogen/androgen production: amenorrhea, abnormal uterine bleeding, virilization.
  • Lymphadenopathy, weight loss.

2. Surface Epithelial Tumors

  • Arise from coelomic mesothelium covering the ovary.
  • Repeated ovulation + scarring → surface epithelium pulled into cortex → small epithelial cysts → metaplasia → neoplastic transformation.

A) Serous Tumors (most frequent ovarian tumor)

Serous cystadenoma (benign)

  • 25 % bilateral; women 30–40 yr.
  • Gross: smooth glistening cyst wall.
  • Histology: small, multilobular, simple papillary processes.

Serous borderline tumor

  • Rarely malignant; usually non-invasive.
  • Younger women, often pregnant.
  • Bilateral in 1/3.
  • 5-yr survival: 100 % if confined to ovary, 75 % if peritoneum involved.

Serous cystadenocarcinoma (malignant)

  • Often bilateral.
  • Gross: nodular, solid, hemorrhagic, necrotic.
  • Histology: nuclear atypia, stratification, glandular complexity, branching papillary fronds.
  • Psammoma bodies (concentrically laminated Ca²⁺) → better prognosis.
  • p53 + BRCA1 mutations.
  • 5-yr survival: 70 % if confined, only 25 % if peritoneum involved.

B) Mucinous Tumors

  • 80 % benign, 10 % borderline, 10 % malignant (less likely malignant than serous).
  • Mucin-secreting cells; larger, often unilateral, filled with sticky gelatinous fluid.

Mucinous cystadenoma

  • Usually endocervical-type epithelium.
  • Tall, columnar, non-ciliated cells with abundant intracellular mucin.

Mucinous borderline tumor

  • Intestinal-type epithelium; resembles villous/tubular adenomas.

Mucinous cystadenocarcinoma / carcinoma

  • 77 % metastatic, 23 % ovarian primary.
  • Stromal invasion distinguishes carcinoma from borderline.
  • Krukenberg tumor — metastatic signet-ring cell carcinoma to ovary (gastric, colorectal).
  • Origins of metastatic mucinous: colon, rectum, appendix, pancreas, bile ducts.
  • Primary: unilateral, > 10 cm, smooth capsule.

C) Endometrioid Tumors

  • Solid or cystic; can develop in endometriotic cysts (chocolate cysts).
  • Morphology identical to endometrioid endometrial carcinoma.
  • Majority malignant; must rule out endometrial primary.

D) Clear Cell Tumors

  • Majority malignant; borderline / benign rare.
  • Can develop in endometriotic cyst.
  • High-grade; advanced → poor prognosis.

E) Brenner Tumors

  • Most are benign.
  • Unilateral; fibrotic stroma with nests of transitional-like epithelium (resembles urinary tract urothelium).
  • Smoothly encapsulated, gray-white.

3. Germ Cell Tumors

Teratoma

  • Tissues from all 3 germ cell layers (ectoderm, endoderm, mesoderm).
  • Arises in first 2 decades (younger → greater risk).

A) Benign (mature) cystic teratoma

  • Mature tissues representing all 3 germ layers.
  • Dermoid cyst — cyst lined by epidermis with skin appendages, filled with hair + sebaceous material.
  • Common tissues: tooth, bone, cartilage, thyroid, neural.
  • Struma ovarii — teratoma composed predominantly of thyroid tissue → hyperthyroidism.

B) Immature malignant teratoma

  • Rare; first 2 decades.
  • Bulky, solid, necrotic.
  • Variety of immature tissue (especially neuroepithelial) → aggressive + metastatic.

4. Sex Cord–Stromal Tumors

  • Derived from ovarian stroma / sex cords of embryonic gonads.

Pure stromal tumors

  • Fibroma — most common sex cord-stromal tumor; benign; may cause ascites + hydrothorax = Meigs syndrome.
  • Thecoma — benign; older women; estrogen production → endometrial hyperplasia/carcinoma.

Pure sex cord tumors

  • Granulosa cell tumor — malignant behavior; late recurrence; estrogen production → endometrial hyperplasia/carcinoma; Call-Exner bodies (gland-like spaces); inhibin marker.
  • Sertoli cell tumor — benign; rare in ovary (more common in testis).

Mixed sex cord-stromal tumors

  • Sertoli-Leydig cell tumor — young women; androgen production → virilization (hirsutism, voice changes, breast atrophy); poorly differentiated → bad prognosis.

5. Clinical Correlation (all ovarian tumors)

  • No symptoms until advanced → high mortality.
  • Non-functioning: lower abdominal pain, abdominal enlargement, pressure on adjacent organs, ascites (peritoneal metastasis).
  • Functioning: hormone-related (estrogen → hyperplasia; androgen → virilization).
  • Tumor marker: CA-125 (epithelial), AFP (yolk sac), β-hCG (choriocarcinoma), inhibin (granulosa cell).

6. Quick Summary Table

Category Examples Hallmark
Surface epithelial Serous, mucinous, endometrioid, clear cell, Brenner Most common; CA-125; serous = psammoma bodies
Germ cell Teratoma, dysgerminoma, yolk sac (AFP), choriocarcinoma (β-hCG) Young women (<20)
Sex cord-stromal Fibroma (Meigs), thecoma, granulosa (estrogen), Sertoli-Leydig (androgen) Hormone production, inhibin marker
Metastatic Krukenberg (signet-ring from stomach/colon) Bilateral, signet-ring

💡 High-yield: #1 cause of gynecologic-cancer death. Surface epithelial = #1 type: serous (most frequent, psammoma bodies, p53/BRCA1), mucinous (Krukenberg = metastatic signet-ring from GI), endometrioid (in chocolate cysts, rule out endometrium), clear cell (in endometriotic cysts), Brenner (transitional epithelium nests). Germ cell: mature cystic teratoma = dermoid cyst (hair, teeth, sebum); immature = aggressive. Sex cord-stromal: fibroma + Meigs syndrome (ascites + hydrothorax), granulosa (estrogen, Call-Exner bodies, inhibin), Sertoli-Leydig (androgen → virilization). Risk: nulliparity + BRCA1/2. Marker: CA-125.