Widespread Intra-abdominal Carcinomatosis from a Rhabdoid Meningioma after Placement of a Ventriculoperitoneal Shunt: A Case Report and Review of the Literature.

Intra-abdominal metastasis (IAM) of central nervous system (CNS) tumors through ventriculoperitoneal shunt (VPS) is rare but has been previously reported (e.g., germinomas and medulloblastomas). However, there has been no previous reports in literature involving meningiomas. A case of primary rhabdoid meningioma with widespread intra-abdominal carcinomatosis after placement of a VPS in a 36-year-old man is described. The patient underwent preoperative angioembolization of the tumor, craniotomy, and surgical excision, followed by postoperative gamma knife radiosurgery. Five months later, he underwent a decompressive craniectomy and surgical excision for tumor recurrence causing raised intracranial pressure and communicating hydrocephalus, necessitating placement of a VPS. One month after placement of the VPS, the patient developed abdominal distension and confusion. He was treated for a VPS infection and the shunt was explanted. He continued to deteriorate with high output from the peritoneal drain placed at the time of shunt explantation. An exploratory laparotomy revealed multiple diffuse peritoneal and omental nodules which had the same histopathological and immunohistochemical morphology as the primary tumor. We reviewed the current literature on IAM of primary CNS tumors through VPS, which revealed that patients belonging to the pediatric age group of the male gender and with a primary intracranial germinoma or medulloblastoma have a higher incidence of IAM. The majority of IAM occurred within 2 years of VPS placement, and patients most commonly present with abdominal distension and ascites. Treatment after diagnosis is varied, and the prognosis is poor, with more than half of the patients dying within a year. It is vital for clinicians to maintain a high index of suspicion for similar patients as early intervention could potentially improve patient outcomes and patient expectations managed more effectively.