Transventricular Migration of Choroid Plexus Carcinoma Causing an Intraoperative Conundrum: A Case Report with a Review of the Literature.

Migrating intracranial tumors are extremely rare occurrences in the neurosurgery literature. Introduction of any factor causing disequilibrium in cerebrospinal fluid circulation and pressure can potentially precipitate transventricular migration of pedunculated intraventricular lesions. The identification of such factors, prior to excision of intraventricular pedunculated tumors, is imperative to avoid intraoperative mismanagement. We report an extremely rare case of transventricular migration of a choroid plexus carcinoma in an infant, possibly precipitated by a ventriculoperitoneal (VP) shunt on the opposite side. This resulted in intraoperative confusion and a subsequent re-exploration of the opposite side for excision of the tumor. The literature provided only two similar occurrences in the past; however, in both cases, the migration was within the same ventricle and was documented prior to definitive resection. We report the first instance of transventricular migration of a tumor to the opposite ventricle following VP shunt which resulted in a negative intraoperative finding requiring a subsequent re-intervention on the opposite side. We believe that for any pedunculated intraventricular lesion, where an emergency management of hydrocephalus takes priority, a repeat neuroimaging is a must prior to definitive resection.