Imaging of an atypical large perineal cyst diagnosed during pregnancy.

Perineal cysts are quite frequent, almost 2% of women developing symptoms related to Bartholin or Gartner cysts. In most cases these cysts derive from embryological remnants or ectopic tissue, or form as epithelial inclusion cysts. These structures are usually asymptomatic unless they are complicated by infection. We report the sonographic and magnetic resonance imaging characteristics of a large perineal cyst diagnosed during the first trimester of an uncomplicated pregnancy, followed by conservative management during pregnancy and surgical excision in the puerperium.