A case report of abdominal implantation and metastasis caused by transventricular peritoneal drainage tube after radiotherapy for intracranial pituitary tumor

• Rare case report: Rare case of peritoneal implantation metastasis caused by malignant pituitary tumor through ventriculoperitoneal drainage tube. • Multidisciplinary team: A multidisciplinary team (MDT) was used to provide a comprehensive treatment plan for the patient. • Implications for treatment strategy: This case emphasizes that the use of ventriculoperitoneal drainage should be cautious in the treatment of intracranial malignant germ cell tumors. This article reports the diagnosis and treatment of a patient with a malignant pituitary tumor who underwent transtumoral ventriculo-abdominal drainage and multiple radiotherapies. The patient exhibited intraperitoneal metastasis and was admitted due to abnormal menopause. Diagnostic examination revealed pituitary gland space occupation, leading to cranial brain surgery. Cerebrospinal fluid was sampled during the operation for cytological examination to consider germinoma. However, the complete removal of the pituitary tumor was hindered by severe cerebral edema, necessitating the temporary placement of a ventriculo-abdominal drainage tube. Following the operation, the patient received 23 sessions of directed radiotherapy, resulting in tumor disappearance as confirmed by pituitary MRI review. Three years later, the patient returned to the hospital due to abdominal pain and anorexia, revealing a substantial abdominal cavity mass. Active surgical intervention was conducted, and postoperative pathology confirmed a secondary malignant tumor in the abdominal cavity originating from dysgerminoma. Following treatment, the patient’s condition improved, and they were discharged. However, intra-abdominal tumor recurrence ensued due to delayed chemotherapy administration, ultimately resulting in death from extensive cerebral infarction. When encountering such patients in the future, if surgery is necessary, how can we select patients who require postoperative maintenance treatment? Which regimen offers greater benefits compared to radiotherapy or chemotherapy? In cases where patients are unable to tolerate chemotherapy and radiotherapy, how can we provide a more specialized treatment plan for them? Analysis of this report underscores the potential enhancement of clinical treatment strategies for such cases.