Mucinous cysts of the vulva

Two cases of mucinous cysts of the vulva are reported. The embryology of the lower female genital tract is described, including the Müllerian duct system, cloaca and urogenital sinus. The relationship of the Wolffian duct system is also included in the discussion. It has been felt in the past that these vulvar cysts are Müllerian-derived. However, it is now deemed more plausible that they are from the entodermally-derived urogenital sinus epithelium. These cysts pose no threat to the patient but are interesting from the standpoint of embryogenesis.