An Atypical Presentation of Vaginal Agenesis

BACKGROUND: Vaginal agenesis is rare and generally presents with primary amenorrhea and cyclic abdominal pain. We describe a case in which the diagnosis was delayed due to lack of initial pelvic examination and atypical findings on imaging. CASE: A 13-year-old girl with a known renal anomaly presented to the emergency department with primary amenorrhea and cyclic abdominal pain. She declined a pelvic examination and had normal laboratory testing and pelvic magnetic resonance imaging results. At 16 months later, she presented again and was diagnosed with vaginal agenesis and a large endometrioma. SUMMARY AND CONCLUSION: This case illustrates the importance of the physical examination in the evaluation of primary amenorrhea. Further, it demonstrates that hematometra may not be present on imaging. Here, an endometrioma was the only abnormality noted on magnetic resonance imaging after 18 months of retrograde menstruation.