CT imaging of ovarian yolk sac tumor with emphasis on differential diagnosis

Yolk sac tumor (YST) of the ovary, also known as endodermal sinus tumor, is a primitive malignant germ cell tumor (GCT) that occurs in girls and young women. Descriptions of this tumor in radiological literature range from entirely solid to predominantly cystic1,2,3. However, these studies were case reports or usually lacked a comparative study with other ovarian tumors. Because the above radiological findings can also be found in many other types of ovarian tumors, a detailed radiological study of ovarian YST with emphasis on differential diagnosis is needed. Characterization of an ovarian mass is of the utmost importance in the preoperative evaluation of an ovarian neoplasm. It can aid in surgical planning, whether exploration or laparoscopic excision, and may help distinguish benign from malignant tumors and thus avoid inappropriate management, or enable the surgeon to anticipate ovarian carcinoma preoperatively so that adequate procedures can be planned4. By now, the combination of operation with chemotherapy remains the mainstay of therapy for YST, so familiarity of its radiological characteristics may permit preoperative diagnosis and improve surgical management of patients. Although similar radiological features can exist in YST and other types of ovarian tumors, predominant or specific imaging features may present in each type of tumor. Knowledge of these key imaging features may allow a specific diagnosis or substantial narrowing of the differential diagnosis, and may help distinguish YST from benign or other types of malignant ovarian tumors. In the present study, we not only demonstrate the radiological characteristics of ovarian YST on computed tomography (CT) images, but also focus on the differential diagnosis of this tumor.