A 27-year-old woman presents to the emergency department with several weeks of worsening shortness of breath, hemoptysis, and headaches. She gave birth to her first child 4 months ago and reports irregular vaginal spotting since then. Physical examination reveals bilateral lung crackles and mild papilledema. Chest x-ray shows multiple cannonball-shaped opacities throughout both lungs, and brain MRI demonstrates multiple hemorrhagic lesions. Serum quantitative β-hCG is markedly elevated. Pelvic ultrasound shows a heterogeneous intrauterine mass with increased vascularity. Which of the following is the most likely diagnosis?
A. Choriocarcinoma
B. Dysgerminoma
C. Endodermal sinus tumor
D. Granulosa cell tumor
E. Serous cystadenocarcinoma
