Objective: To present an unusual side effect of therapy for adolescent menorrhagia, with commentary on management options.
Design: Case report.
Setting: Tertiary gynecologic center.
Patient(s): A 13-year-old girl presenting with profuse uterine bleeding.
Intervention(s): Dysfunctional uterine bleeding was diagnosed, and pharmacologic therapy with a monophasic oral contraceptive (OC) pill was introduced.
Main outcome measure(s): A large decidual cast occurred during treatment.
Result(s): After finishing therapy with OC followed by three cycles of cyclic progestogen, the patient experienced regular menses.
Conclusion(s): A large decidual cast may occur during treatment of adolescent menorrhagia with OCs; patients should be informed about this possibility, to reduce stress connected with the appearance of this side effect.