A 16-year-old girl from Mumbai presents to the emergency department with acute severe left lower abdominal pain and nausea for 6 hours. On examination, she is in distress with a rigid, tender left lower abdomen and guarding. Pelvic ultrasound reveals a 15 cm left ovarian mass with internal hemorrhage and free fluid in the pelvis. Serum AFP is 2,200 ng/mL (normal <10), β-hCG is 12 mIU/mL (normal <5), and hemoglobin is 9.2 g/dL. Emergency left oophorectomy is performed. Histopathology shows sheets of cuboidal cells with hyaline globules, microcystic pattern, and areas of hemorrhage and necrosis. What is the most likely diagnosis?