# Subsequent ovarian yolk sac tumor after operation of ovarian mature teratoma: a case report and review of the literature

## TL;DR

A rare case of a woman developing a malignant yolk sac tumor shortly after being treated for a benign ovarian tumor is reported, highlighting the need for close monitoring.

## Contribution

This case report highlights the rare occurrence of yolk sac tumor following mature teratoma and emphasizes the importance of postoperative surveillance.

## Key findings

- YST can develop shortly after surgical treatment of mature teratoma.
- Regular follow-up can enable early detection of secondary malignant tumors.
- Early detection and treatment can lead to favorable patient outcomes.

## Abstract

Ovarian mature teratoma represents a benign ovarian tumor, while ovarian yolk sac tumor (YST, endodermal sinus tumor) is a rare malignant tumor predominantly affecting young women, often associated with a grim prognosis post-metastasis. Both ovarian mature teratoma and ovarian YST are germ cell tumors. There are few studies on the correlation between ovarian YST and mature teratoma. Recurrence or malignant transformation may occur following the surgical intervention for ovarian mature teratoma. However, the occurrence of YST subsequent to such procedures is notably rare. In this investigation, we reported a case involving a 24-year-old unmarried woman with both mature ovarian teratoma and YST within a brief 1-year interval. Regular reexamination protocols facilitated the early-stage detection of YST. The patient underwent surgical treatment, chemotherapy, and measures to preserve ovarian function, resulting in a favorable prognosis. Our primary purpose is to distill clinical insights from the diagnostic and therapeutic journey of this patient. Our purpose is to enhance medical professionals’ awareness that YST may be secondary to mature teratoma. Additionally, we underscore the critical importance of routine postoperative surveillance for ovarian mature teratoma, emphasizing its pivotal role in early malignant tumor detection—a factor paramount to the prognosis of patients.