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

Abstract

Ovarian yolk sac tumors (YSTs) are rare neoplasms. No radiological study has been done to compare the imaging findings between this type of tumor and other ovarian tumors. Here we analyzed the CT findings of 11 pathologically proven ovarian YSTs and compared their imaging findings with 18 other types of ovarian tumors in the same age range. Patient age, tumor size, tumor shape, ascites and metastasis of two groups did not differ significantly (P > 0.05). A mixed solid-cystic nature, intratumoral hemorrhage, marked enhancement and dilated intratumoral vessel of two groups differed significantly (P < 0.05). The area under the ROC curve of four significant CT features was 0.679, 0.707, 0.705, and 1.000, respectively. Multivariate logistic regression analysis identified two independent signs of YST: intratumoral hemorrhage and marked enhancement. Our results show that certain suggestive CT signs that may be valuable for improving the accuracy of imaging diagnosis of YST and may be helpful in distinguishing YST from other ovarian tumors.

Figure 1. 27-year-old young woman with ovarian yolk sac tumor.

A Precontrast CT scan shows a high density lesion within a solid-cystic mass (black arrow). Massive ascites is seen (black arrow). B This high density lesion has no enhancement on post-contrast CT image, which indicates the lesion is hemorrhage (black arrow). Heterogeneous marked enhancement of the tumor and enlarged intratumoral vessels are detected (black arrow). C Multiple peritoneal metastases (black arrows) with marked enhancement and massive ascites (black arrow) are seen.

Figure 2. 24-year-old young woman with bilateral ovarian yolk sac tumors.

A A solid cystic mass with heterogeneous moderate to marked enhancement in the left pelvic cavity (black arrow). B An enlarged vessel is seen in the mass (white arrow). C The other solid cystic mass with an enlarged intratumoral vessel is seen in the right pelvic cavity (black arrow). Ascites is also detected.

Figure 3. 16-year-old girl with ovarian yolk sac tumor.

A predominantly cystic mass with heterogeneous marked enhancement in the pelvic cavity (white arrow). Multiple enlarged vessels are seen in the mass (black arrow). Peritoneal metastases (white arrow) with marked enhancement and massive ascites (black arrow) are also seen.

Figure 4. 14-year-old girl with immature teratoma.

A A solid-cystic mass with irregular shape is seen in the pelvic cavity. The tumor contains fatty tissues (black arrow) and calcification (black arrow) on precontrast image. B The tumor shows heterogeneous mild to moderate enhancement (black arrow).

Figure 5. 29-year-old woman with bilateral serous cystadenocarcinomas.

A Bilateral ovarian masses (black arrows) with irregular shape, solid cystic nature, heterogeneous moderate to marked enhancement and ascites (white arrow) are seen in the pelvic cavity. B Multiple peritoneal metastases (black arrows) and massive ascites (black arrow) are seen.

Figure 6. 27-year-old young woman with mucinous cystadenocarcinoma.

The tumor shows oval shape, predominantly cystic nature, heterogeneous moderate to marked enhancement (white arrow) and intratumoral papillary projection (white arrow). Ascites is also detected (white arrow).

Figure 7. 18-year-old woman with Sertoli-Leydig cell tumor.

A predominantly solid mass contains little cystic areas (black arrows) in the right pelvic cavity. The tumor shows heterogeneous mild to moderate enhancement on post-contrast scan. Little ascites is also detected (white arrow).