Case Report: Primary choriocarcinoma of the pineal region

Primary intracranial choriocarcinoma (PICCC) is a rare, highly malignant non-germinomatous germ cell tumor (NGGCT), primarily affecting children and adolescents with a male predominance. It most commonly arises in the pineal region and sella turcica. This report describes a case of primary choriocarcinoma in the pineal region. CT imaging revealed a patchy area of abnormal high density with slight internal density variation and small nodular calcifications. MRI showed a mixed signal pattern, predominantly slightly short T₁-weighted and short T₂-weighted signals. Contrast-enhanced imaging demonstrated heterogeneous enhancement. Surgical pathology specimens showed immunohistochemical positivity for HCG(+), HPL(+), CK(PAN)(+), EMA(partial+), p53(partial+), PLAP(placental alkaline phosphatase, partial+), CD117(partial+), and Ki-67 proliferation index: 20%. The pathological findings were consistent with pineal region choriocarcinoma. The patient's serum β-HCG level decreased to <0.1 mIU/mL one year after surgery, and the child remained in good condition without recurrence during the 2-year follow-up.