Low-Grade Astrocytoma within a Mature Cystic Teratoma in an Adolescent Patient.

BACKGROUND: Mature cystic teratomas are the most common ovarian neoplasm in adolescents. They are typically benign, however, malignant transformation rarely occurs. We report a low-grade astrocytoma arising from a mature cystic teratoma in an adolescent patient.

CASE: The patient was a 12-year-old girl with an asymptomatic ovarian cyst and subsequent cystectomy. Final pathology identified a solid tumor with glial tissue within the cyst, reported as low-grade astrocytoma arising in a mature cystic teratoma.

SUMMARY AND CONCLUSION: There are few data on astrocytomas in the gynecologic tract. Risk factors for malignant transformation in a mature cystic teratoma include increased age, postmenopausal status, elevated carcinoma antigen 125, and large tumor size. Interestingly, this patient had a history of partial trisomy 20, which has been associated with teratoma formation in a mouse model.