An Abdominopelvic Mass in a 13-Year-Old Adolescent Girl

Apreviously healthy 13-year-old adolescent girl presented with a 1-week history of vague abdominal pain, swelling, and constipation and a single episode of emesis. Her medical history consisted of asthma treated with albuterol. Her surgical history included a tonsillectomy and an adenoidectomy. Her last menstrual period was 3 days prior to admission, and she denied any sexual activity. Significant physical findings were a slightly distended, nontender abdomen and a palpable pelvic mass. The chemistry profile and complete blood count were within the reference range. Results of the urinalysis were negative, and the urine b-human chorionic gonadotropin level was within the reference range. The a-fetoprotein level was 6.6 ng/mL. A computed tomographic scan