A 16-year-old girl has a 10 cm ovarian mass. Histology shows immature neuroepithelium with rosettes and neural tubules, along with mature cartilage and thyroid tissue. Immature neuroepithelium occupies less than one low-power field (40x) per slide. What is the correct grade and prognosis?

• A Mature cystic teratoma with malignant transformation; poor prognosis
• B Grade 2 immature teratoma; requires adjuvant chemotherapy
• C Grade 3 immature teratoma; poor prognosis
• D Grade 1 immature teratoma; excellent prognosis with surgery alone ✓

Explanation

Immature teratoma grading is based on quantity of immature neuroepithelium: Grade 1 has <1 low-power field (40x) of immature neuroepithelium per slide. Grade 1 tumors have excellent prognosis with surgery alone. Grade 2 has 1-3 low-power fields, Grade 3 has >3 low-power fields (requires chemotherapy). Mature teratoma lacks immature neuroepithelium.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.