Ovarian dysgerminoma detected by 18F-FDG PET/CT technique: A case report

Ovarian dysgerminoma (OD) mostly affect young women, have a rapid growth rate, and could result in complications such as rupture, hemoperitoneum or torsion, and acute abdomen. However, there have been no reports of OD on F-FDG PET/CT imaging.

A 21-year-old female patient was admitted to our hospital on February 6, 2016, due to "reduced menstrual flow with abdominal distension for 3 months".

Color Doppler ultrasound showed a large solid mass in the abdomen and pelvis. Serum carbohydrate antigen 125 (CA125) was elevated significantly. Subsequent computed tomography (CT) of chest showed a large effusion in the right thoracic cavity. Abdominal CT scan revealed the presence of a solid mass occupying a large space in the middle and lower abdomen, suggesting that it derived from the left ovary. Then, she underwent F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography (PET)/CT examination for further diagnosis and staging. PET/CT showed a large occupying lesion in the abdomen. The maximum standardized uptake (SUVmax) of F-FDG was 15.8. No obvious hypermetabolic metastases were observed in the other parts of the body. Postoperative pathology and immunohistochemistry confirmed the ovarian dysgerminoma.

The patient underwent surgery. Chemotherapy was successfully carried out post-operation.

Fortunately, the patient is responding well to treatment and the postoperative recurrence-free survival time has been more than 3 years.

OD usually occurs in young women and is characterized by large solid pelvic mass. The F-FDG PET/CT scan shows abnormally increased metabolism of the tumor. Because of the high metabolic characteristics, F-FDG PET/CT may be of great significance in the diagnosis and staging of OD.