creation date: 2026-01-05 14:50
tags: Workups
Ovarian Cyst
Background
Ovarian cyst are fluid-filled sacs that can form on one or both ovaries. Ovarian cysts are a common form of pelvic/adnexal mass of which over thirty types exist.
While most ovarian cysts are functional and benign, complications require prompt management.
Differential Diagnosis
Functional cysts
These are physiological cysts that occuring during normal menstrual cycle.
Follicular cyst:
- Occurs when follicles fail to rupture during ovulation (may be due to excessive FSH or absence of LH surge)
- Smooth, thin-walled, unilocular
- Grows due to hormonal stimulation; usually larger than 2.5 cm
Corpus luteal cyst: - Occurs when corpus luteum fails to dissolve after 14 days
- Complex or simple, thick-walled, contain internal debris
- Usually grows to 3 cm
Both functional cysts can turn into hemorrhagic cyst but are generally asymptomatic and spontaneously resolve without treatment.
Theca lutein cysts
Overstimulation from elevated hCG levels. Occurs in women with:
- Pregnant
- Gestational trophoblastic disease
- Multiple gestation
- Ovarian hyperstimulation
Polycystic ovary syndrome (PCOS)
- 5-10% of women
- Cause of infertility
- Associated with diabetes and cardiovascular disease
- Enlarged ovary with multiple small follicular cysts
- Due to excess androgen hormones
Neoplastic cysts
Epithelial malignancies include:
- Serous carcinoma
- Mucinous carcinoma
- Endometroid carcinoma
- Clear cell carcinoma
- Malignant Brenner tumour
Malignant germ cell tumours include:
- Immature teratoma
- Endodermal sinus tumours
- Embryonal carcinoma
- Polyembryoma
Endometriosis can result in endometriomas which are referred to as “chocolate cysts” as they contain dark, thick, gelatinous blood products.
Initial Evaluation
History
While most cysts are incidental and asymptomatic, symptoms may include:
- Unilateral pain or pressure in lower abdomen
- Pain may be intermittent or constant
- Characterized as dull or sharp
Ruptured cyst or ovarian torsion may present as:
- Sudden onset of acute severe pain
- Associated with nausea and vomiting
- Irregular menstrual cycle
- Abnormal vaginal bleeding
Physical Exam
Bimanual exam should palpate ovaries. Determine:
- Location
- Shape (regular or irregular)
- Size
- Consistency
- Level of tenderness
- Mobility
Investigations
If patient is pre-menopausal, a urine pregnancy test or serum b-hCG should be performed.
Laboratory studies
- CBC (assess for anemia from bleed)
- Urinalysis (r/o UTI and stones)
- Endocervical swab (assess for pelvic inflammatory disease)
- Cancer antigen 125 (CA125) - for ovarian cancer
Imaging
Transvaginal ultrasound ± abdominal ultrasound (depending on anatomy)
- Cannot rule out torsion with doppler
- Suspicious findings for malignancy include:
- Cyst size >10 cm
- Complex multilocular mass
- Papillary excrescences or solid components
- Irregularity
- Thick septations
- Evidence of ascites
- Increased vascularity on colour doppler
CT and MRI are typically not indicated and gynecologic oncology should be consulted prior to further workup if needed.