Background: Transverse vaginal septum is a rare cause of primary amenorrhea. It has a reported incidence of 1:2,100-1:72,000 and a variety of clinical presentations.
Case: A 16-year-old patient presented with primary amenorrhea and a large abdominal mass that was palpated on clinical exam and confirmed on MRI imaging. A diagnosis of transverse vaginal septum was ultimately made and the patient underwent a successful surgical excision of the septum and vaginal reconstruction.
Conclusion: The presentation, etiology, diagnosis, and surgical treatment of a transverse vaginal septum are discussed.