## **Core Concept**
Choriocarcinoma is a type of gestational trophoblastic neoplasia (GTN) that can occur after any pregnancy, characterized by high levels of beta-human chorionic gonadotropin (β-hCG). It is a highly malignant tumor but also highly responsive to chemotherapy. The management of choriocarcinoma involves chemotherapy, and the choice of regimen depends on the FIGO (International Federation of Gynecology and Obstetrics) risk score, which takes into account factors like β-hCG levels, largest tumor diameter, site of metastases, and previous failed chemotherapy.

## **Why the Correct Answer is Right**
Given the patient's high serum β-hCG level of 2x10^5 IU/L, which indicates a high tumor burden, and considering that choriocarcinoma is highly sensitive to chemotherapy, the most appropriate next step in management would be to start chemotherapy immediately. The FIGO scoring system helps in stratifying patients into low-risk and high-risk groups, which guides the choice of chemotherapy regimen. For high-risk patients or those with a high β-hCG level, a more aggressive regimen like EMA-CO (Etoposide, Methotrexate, Actinomycin D, Cyclophosphamide, and Vincristine) is often recommended.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and cannot be evaluated.
- **Option B:** This option is blank and cannot be evaluated.
- **Option D:** This option is blank and cannot be evaluated.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that in the management of gestational trophoblastic neoplasia, including choriocarcinoma, β-hCG levels are used not only for diagnosis but also for monitoring response to treatment. A high β-hCG level, as seen in this patient, necessitates prompt initiation of chemotherapy. The EMA-CO regimen is specifically used for high-risk GTN, which includes choriocarcinoma with high β-hCG levels, and is associated with a good response rate even in the presence of brain or liver metastases.

## **Correct Answer:** .