A brainstem mass of Müllerian type Epithelial Origin without any primary cancer source.

Brainstem tumors are rare, even rarer is a brainstem tumor containing tissues of an embryologic gynecologic origin. We report a very rare case of presence of a calcified heterogeneously contrast enhancing brainstem mass of Müllerian origin in a patient in a 38 year old female with no female genital tract cancer and past surgical history of ventriculoperitoneal (VP) shunt placement for congenital hydrocephalus. To our knowledge this is the very first and unusual case of a mass of gynecologic origin in the brainstem region especially in the setting of no history of gynecological tumor. The authors also reviewed the literature for all tumors reported for anterograde and retrograde dissemination of tumor cells through VP shunt. This case is a reaffirmation of the importance of brain tumor location and tissue diagnosis for the purpose of adjuvant treatment of neurosurgical lesions in the neurocritical care setting. It also highlights the role of catheters as potential routes of iatrogenic transmission not just in anterograde but also in a retrograde manner to the CNS, which is very unusual. This is the only second case to report retrograde flow of tumor cells from an extraneural source up the VP catheters. The authors suggest that intraperitoneal chemotherapy should be considered in the cases of known extraneural abdominal malignancies of high malignant potential with or without the presence of peritoneal infiltration in order to avoid dissemination through VP shunts.

Surgical Management of Giant Retrocerebellar Arachnoid Cysts with a Cystoventricular Stent After Long-Term, Independent, and Simultaneous Intracystic and Intraventricular Pressure Monitoring.

BACKGROUND: Outcomes of surgical treated patients with giant retrocerebellar arachnoid cysts with the available typically preferred techniques frequently are unsatisfactory. OBJECTIVES: We hypothesized that a pressure gradient may exist between the cyst and the ventricular system that may be responsible for the posterior fossa-related symptoms and headaches, and, if so, that connecting both cavities by means of a shunt catheter (i.e., cystoventricular stent), the pressure differences would equilibrate and the symptoms resolve. To prove our hypothesis, we decided to simultaneously monitor the intracyst pressure and the intraventricular pressure. METHODS: This was a retrospective chart review analysis of 5 consecutive patients with giant retrocerebellar arachnoid cysts treated between 2014 and 2016. RESULTS: Four patients underwent 3 days of continuous intracranial pressure monitoring, and 1 patient was monitored in the surgical suit. Cyst and ventricular pressures tended to be within normal accepted values in all patients, and a pressure gradient was noticed only in the 2 patients with previous cyst surgeries. All patients were treated with a cystoventricular stent, and overall, had long-term sustained good outcomes, with resolution of symptoms in 3 and significant improvement in 2. CONCLUSIONS: Patients with symptomatic large retrocerebellar arachnoid cysts do not seem to have increased intracranial pressure, and regardless of the presence or absence of a pressure gradient between the cyst and the ventricles, a cystoventricular stent seems to be effective and the best first surgical option to offer.