Paratubal Cyst

A paratubal cyst is a cyst close to the fallopian tube, often at the fimbrial end (hydatid cyst of Morgagni). It arises from Müllerian or Wolffian remnants.

• It is common in adolescents and young women.
• It may twist the tube, and torsion is more frequent than with ovarian cysts.
• Most are benign, simple and small.

Usually no symptoms; lower abdominal pain, pelvic pressure, or sudden pain with vomiting from torsion.

• A mobile, small adnexal mass, sometimes tender.
• Differential diagnosis: simple ovarian cyst, paraovarian cyst, hydrosalpinx, ectopic pregnancy, endometrioma, cystadenoma, appendiceal mass.
• Complications: torsion of the tube and ovary, rupture, haemorrhage and infertility from tubal distortion.

Diagnosis is by transvaginal ultrasound, showing a cyst beside a separate ovary and tube.

• Transvaginal ultrasound: thin-walled anechoic cyst beside the ovary and tube, with the ovary seen separately.
• Pregnancy test.
• MRI or laparoscopy if the origin is unclear.
• Histology after removal.
• Check for hydrosalpinx and tubal dilatation.

Observe small asymptomatic cysts, and operate for large cysts or torsion while preserving the ovary and tube.

• Supportive: reassure; advise to report sudden pain or vomiting; analgesia.
• 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 small asymptomatic cysts below 5 cm with yearly ultrasound; laparoscopic excision of the cyst wall preserving the tube and ovary for cysts above 5 cm, symptomatic or growing. Urgent laparoscopy for torsion with detorsion and excision of the lead point.
• Special groups: in pregnancy observe and operate for torsion or rupture only; in adolescents conserve the ovary and tube; avoid ibuprofen from 28 weeks.
• Red flags: severe sudden pain with vomiting, rapid growth, solid parts, fever.
• Follow-up: ultrasound at 6 months, then yearly while observed; review at 2 and 6 weeks after surgery.