Gynecology Topic 29. Benign neoplasms of ovaries

I. Benign Neoplasms of the Ovaries

General

• Benign ovarian neoplasms: Non-functional ovarian tumors; unlike functional cysts, they usually do not regress spontaneously.
• Main classification by tissue of origin:

1. Epithelial tumors
2. Sex cord-stromal tumors
3. Germ cell tumors

• Most are slow-growing and asymptomatic until large.
• Benign and malignant tumors may overlap clinically → ultrasound morphology and histology are important.

II. Types

1. Epithelial Tumors

1. Serous cystadenoma

• Most common benign epithelial ovarian tumor.
• Usually unilateral.
• Gross: Unilocular, thin-walled cyst filled with clear serous fluid.
• Lining: Ciliated columnar epithelium resembling tubal epithelium.
• US: Unilocular, anechoic cyst if small/simple.
• Histology: Psammoma bodies may be present, but are more typical/frequent in serous borderline or malignant tumors.

2. Mucinous cystadenoma

• 2nd most common benign epithelial ovarian tumor.
• Usually unilateral; bilateral disease is uncommon.
• Gross: Very large multilocular cyst, may grow >30 cm.
• Contents: Thick mucinous fluid.
• Lining: Mucin-secreting columnar epithelium.
• Complication: Rupture; mucinous tumor spillage should be avoided.

2. Sex Cord-Stromal Tumors

1. Fibroma

• Most common benign sex cord-stromal tumor.
• Composed of fibroblast-like spindle cells producing collagen.
• Gross: Firm, solid, white, smooth, usually unilateral.
• Usually hormonally inactive.
• Meigs syndrome: Ovarian fibroma + ascites + pleural effusion → Resolves after tumor removal.

2. Sertoli-Leydig cell tumor / androblastoma

• Rare sex cord-stromal tumor; may be benign or low malignant potential depending on differentiation.
• Produces androgens, especially testosterone.
• Clinical: Virilization → Amenorrhea, hirsutism, acne, deep voice, clitoromegaly.
• Gross: Solid, firm, white/yellow-white mass, usually unilateral.

3. Granulosa-theca cell tumor / thecoma

• Estrogen-producing sex cord-stromal tumor; often low malignant potential rather than purely benign.
• Clinical clue: Precocious puberty, AUB/menorrhagia or postmenopausal bleeding.
• Risk: Endometrial hyperplasia/cancer from estrogen excess.

4. Brenner tumor

• Usually benign epithelial tumor with transitional-type cells.
• Gross: Small, solid, fibrous ovarian mass.

3. Germ Cell Tumors

1. Mature cystic teratoma / dermoid cyst

• Most common ovarian neoplasm in women <30 years.
• Derived from all 3 germ layers:

• Ectoderm → Hair, sebaceous glands, squamous epithelium, teeth.
• Mesoderm → Cartilage, bone, muscle, fat.
• Endoderm → Respiratory/GI epithelium, thyroid tissue.

• Usually unilateral.
• Slow-growing; malignant transformation is rare, mainly in older women.
• US: Complex cyst with echogenic components, fat-fluid level, calcifications, acoustic shadowing / "tip of the iceberg" sign.
• Complication: Torsion risk.
• Struma ovarii: Teratoma composed predominantly of thyroid tissue; may cause hyperthyroidism.

III. Clinical Features

General Presentation

• Often asymptomatic and detected incidentally.
• Lower abdominal/pelvic pain → acute severe pain suggests torsion, rupture or hemorrhage.
• Abdominal distention, bloating, fullness or palpable mass.
• Irregular menstruation or amenorrhea if hormonally active.
• Pressure effects: Urinary frequency/retention/incontinence, constipation.

Exam Findings

• Benign-appearing mass: Smooth, mobile, cystic or well-circumscribed, usually unilateral, non-tender.
• Fibroma/Brenner tumor: Solid, firm mass.
• Hormonal clues:

• Estrogenic symptoms → Granulosa-theca tumor: AUB, endometrial hyperplasia, breast tenderness.
• Androgenic symptoms → Sertoli-Leydig tumor: Virilization.

Complications

• Ovarian torsion.
• Rupture → Pain, peritoneal irritation; mucinous rupture may spill mucin.
• Hemorrhage or infection.
• Pressure symptoms from very large tumors.
• Meigs syndrome with fibroma.

IV. Diagnosis

Initial Work-Up

• History + physical examination.
• Pregnancy test in reproductive-age patients → exclude ectopic pregnancy.
• Pelvic examination: Cystic/smooth/mobile adnexal mass or solid fibroma-like mass.

Imaging

• Transvaginal US ± transabdominal US → First-line.
• Assess: Size, laterality, cystic vs solid, simple vs complex, septations, papillary projections, ascites, Doppler vascularity.
• CT/MRI → Large mass, unclear origin, suspected malignancy or preoperative mapping.

Tumor Markers

• CA-125: May be elevated, but nonspecific; more useful for malignancy risk in postmenopause than in premenopause.
• Androgens/testosterone: If virilization suggests Sertoli-Leydig tumor.
• Estradiol/inhibin/AMH: If granulosa-theca tumor is suspected.
• AFP, β-hCG, LDH: Use selectively when malignant germ cell tumor is in the differential.

Suspicion of Malignancy

• Suspicious features: Solid/irregular mass, papillary projections, thick septations, bilateral mass, ascites, fixed mass, rapid growth, postmenopausal status, elevated CA-125.
• Definitive diagnosis: Histology after cystectomy/oophorectomy; avoid simple needle biopsy if malignancy is suspected because of spillage risk.

V. Treatment

Observation

• Small, simple, benign-appearing cystic masses in reproductive-age women may be observed with repeat US.
• True benign neoplasms usually do not disappear like functional cysts → persistent/enlarging masses often need surgery.

Surgical Management

• Premenopausal, fertility desired → Laparoscopic ovarian cystectomy when feasible; preserve ovarian tissue.
• Large dermoid/cystadenoma, symptomatic or enlarging mass → cystectomy or oophorectomy depending on separability and ovarian preservation.
• Postmenopausal, large, recurrent or solid mass → Oophorectomy or unilateral/bilateral salpingo-oophorectomy.
• Mucinous cystadenoma → remove intact if possible; avoid rupture/spillage.
• Suspected malignancy → Referral to gynecologic oncology; laparotomy/staging procedure rather than cyst rupture/spillage.