The application of 18F-FDG PET/CT in ovarian immature teratomas when pathological examination results contradict clinical observations: a case report

RATIONALE: Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) could reveal potential lymph node involvement and assisted locating sample sites for pathological examinations. PATIENT CONCERNS: Help choose the right treatment strategies for patients. To better stage immature ovarian teratomas with 18F-FDG PET/CT when lymphatic metastasis is suspected while lymph node biopsy results are negative. DIAGNOSES: The ultimate pathological diagnosis was left ovarian cancer, an immature teratoma (IMT) Grade 1. INTERVENTIONS: Surgery was the initial treatment option. Chemotherapy (BEP scheme: Bleomycin 30 mg d1, 7 + Etoposide 100mg d1-6 + Cisplatin 50mg d1-3) was then administered. OUTCOMES: The post-operational pathological examination additionally showed a small number of tumor cells in para-aortic lymph nodes. The end-of-treatment disclosed no recurrent tumors and serum levels of AFP (2.9 ng/mL), hCG (0.12 mIU/L), and CA-125 (11.4 IU/mL) were normal. LESSONS: 18F-FDG PET/CT successfully detected lymphatic metastasis when lymph node biopsy results were negative, which would be of great significance in detecting metastasis and monitoring reoccurrence of ovarian immature teratomas.