Ovarian Mass

Sara M. O’Hara, MD, FAAP

DIFFERENTIAL DIAGNOSIS

Common

Functional Ovarian Cysts
Hemorrhagic Cyst
Endometrioma
Ovarian Torsion
Mature Teratoma
Tuboovarian Abscess
Polycystic Ovary Syndrome

Less Common

Ectopic Pregnancy
Dysgerminoma
Yolk Sac Tumor
Sertoli-Leydig Cell Tumor

Rare but Important

Ovarian Fibroma
Granulosa Cell Tumor, Juvenile

ESSENTIAL INFORMATION

Key Differential Diagnosis Issues

Ovarian masses can be
- Benign
- Borderline (low malignant potential)
- Malignant
Benign
- Functional cysts
- Hemorrhagic cysts/endometriomas
- Serous and mucinous cystadenomas
- Mature teratomas
- Fibromas
Borderline (low malignant potential)
- Serous tumors (65%)
- Mucinous tumors (30%)
- Endometrioid tumors
- Clear cell, Brenner cell
- Monodermal teratoma (struma ovarii, carcinoid, neural tumors)
- Mixed neoplasms
Malignant
- Epithelial ovarian carcinoma
  - 70% of all ovarian tumors
  - Postmenopausal women
- Germ cell tumors
  - 20% of all ovarian tumors
  - These cell types more common in adolescents/young adults
  - Dysgerminoma
  - Yolk sac/endodermal sinus
  - Embryonal carcinoma
  - Choriocarcinoma
  - Immature teratoma
  - Mixed
- Sex cord stromal tumor, including
  - 8% of all ovarian tumors
  - Sertoli-Leydig cell
  - Granulosa theca cell
- Metastatic spread to ovary
Clues to malignancy on imaging
- Persistent or growing mass
- Solid tumors or mixed solid and cystic
- Size > 8 cm
- Local invasion
- Peritoneal fluid
- Nodular omentum (implants)
- Adenopathy

Helpful Clues for Common Diagnoses

Functional Ovarian Cysts
- Most are “simple” cysts
- Large cysts with diameter > 3 cm should be re-imaged
- Physiologic cysts will involute in 6-8 weeks
Hemorrhagic Cyst
- Complex cysts containing debris ± echogenic free fluid
- Should resolve with next menstrual cycle
Endometrioma
- Low-level, homogeneous echoes (“chocolate” cyst)
- Endometriosis in childhood or adolescence associated with genital tract anomalies
Ovarian Torsion
- Excessive rotation of ovary, fallopian tube, or both
- Causes ischemia and pain
- Not typically associated with masses in pediatrics, unlike adult population
- 1/2 of cases occur in premenarchal girls
- ˜ 10% occur neonatally
- Ultrasound
  - Unilateral enlarged ovary; 5x volume highly predictive
  - Stromal edema: Peripheral follicles
  - Free pelvic fluid/blood
  - Areas of hemorrhage
  - Normal Doppler exam does not exclude torsion
- Treatment: Urgent surgical detorsion, conservation of ovarian tissue
- Salvage rates for ovarian torsion are much better than for testicular torsion
- Length of symptoms does not predict viability
Mature Teratoma
- Benign germ cell tumor
- ˜ 60% of ovarian neoplasms in women < 40 years old
- Contains all 3 germ cell lines
- Hair, fat, teeth, calcification seen on imaging
- Cysts may contain oily, milky, or serous fluid
- Generally have well-defined capsule
- Bilateral in up to 15%
Tuboovarian Abscess
- Fever, cervical tenderness, vaginal discharge
- Ultrasound shows inflammation and ill-defined structures
- Focal fluid/pus collections in tubes and adnexal spaces with thick hyperemic rim
- Generally treated medically, not surgically
Polycystic Ovary Syndrome
- Ovarian dysfunction, hyperandrogenism, polycystic ovary
- ≥ 12 follicles per ovary
- Ovarian volume > 10 mL

Helpful Clues for Less Common Diagnoses

Ectopic Pregnancy
- Check quantitative β-hCG level
- Decidual reaction in uterus with no intrauterine gestational sac
- Enlarged, hyperemic adnexa
- Gestational sac may be visible in adnexa
  - Usually on same side as corpus luteum
- Occasionally implant distant from uterus
Dysgerminoma
- ˜ 50% of all germ cell tumors
- 5% secrete β-hCG
- Similar to male seminoma
- Masses tend to be large and heterogeneous
- 15% recur but are re-treated with good prognosis
Yolk Sac Tumor
- a.k.a. endodermal sinus tumor
- ˜ 25% of all germ cell tumors
- May secrete α-fetoprotein
- Poor prognosis without adjuvant chemotherapy
  - 5-20% survival with surgery alone
Sertoli-Leydig Cell Tumor
- Sex cord stromal tumor
- ˜ 75% occur in women < 40 years old
- May cause virilization
- Heterosexual precocious puberty
- Recurrence and malignant behavior seen with poorly differentiated subtypes

Helpful Clues for Rare Diagnoses

Ovarian Fibroma
- ˜ 4% of all ovarian tumors
- Meigs syndrome with ascites and pleural effusions
Granulosa Cell Tumor, Juvenile
- ˜ 2% of all ovarian tumors
- < 5% of these are juvenile type
- Often secrete estrogen