Follicular Ovarian Cyst

A follicular ovarian cyst is a persistent, enlarged graafian follicle of more than 3 cm that fails to rupture at ovulation or fails to regress.

• It is lined by granulosa cells, filled with clear fluid, and is thin-walled.
• Most arise in the first half of the menstrual cycle and are found incidentally.
• Most resolve in one to three cycles.

Often none; some women have unilateral pelvic ache, delayed menses, or short cycles.

• A smooth, mobile, mildly tender adnexal swelling.
• Differential diagnosis: corpus luteum cyst, serous cystadenoma, endometrioma, paraovarian cyst, hydrosalpinx, ectopic pregnancy, ovarian torsion, polycystic ovaries.
• Complications: rupture, torsion, haemorrhage into the cyst and, in rare cases, hormone excess in young girls leading to premature puberty.

Diagnosis is by transvaginal ultrasound after a pregnancy test.

• Pregnancy test.
• Transvaginal ultrasound: unilocular anechoic cyst with a thin wall, 3 to 8 cm, with no internal flow.
• Repeat ultrasound after menses to confirm resolution.
• CA-125 and MRI only if septa or solid components appear.
• In prepubertal girls, check height, breast development and bone age for hormone excess.

Observe, since most cysts resolve, and operate only for complications or persistence.

• Supportive: reassure; analgesia; advise to report sudden pain, fever or vomiting.
• Pharmacological: paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours) and ibuprofen 400 mg oral 8-hourly with food (maximum 1.2 g in 24 hours) for 3 to 5 days. In girls, paracetamol 15 mg/kg oral 6-hourly (maximum 1 g per dose).
• Procedures: observation for 6 to 12 weeks; ultrasound-guided aspiration is not advised because the cyst refills; laparoscopic cystectomy for cysts above 7 cm, persistent beyond 3 months, or complicated by torsion.
• Special groups: in pregnancy observe; surgery is for torsion or rupture only, and avoid ibuprofen from 28 weeks. In girls with premature puberty refer for endocrine review.
• Red flags: severe pain, vomiting, fever, shock, new septa or solid areas.
• Follow-up: repeat ultrasound at 6 to 8 weeks; reassess at 3 months if persistent.