Andrea: An Unusual Brain Tumor
It started with loss of balance, numbness of the left arm and severe headaches that gradually worsened. Andrea was 15 when her mother, Luisa, who works for a neurology practice, brought her in for neurological testing and a CT scan. The imaging study revealed an unusually large, dense mass in the posterior fossa - the lower back of the skull containing the brain stem and cerebellum- with obstructive hydrocephalus, a buildup of fluid inside the skull that leads to brain swelling.
The neurologist referred Andrea to David Sandberg, M.D.,F.A.A.N.S., F.A.C.S., F.A.A.P., who affiliated with the Mischer Neuroscience Institute at Memorial Hermann in 2012 as director of pediatric neurosurgery. He holds joint appointments as an associate professor in the departments of Neurosurgery and Pediatric Surgery at The University of Texas Health Science Center at Houston (UTHealth) Medical School.
"On examination, Andrea was a healthy child with normal speech and mental abilities," Dr. Sandberg says. "She had mild partial loss of movement in the left central area of her face, was minimally unsteady and uncoordinated in walking, but was otherwise neurologically intact. Her symptoms were strikingly mild compared to the extent of the abnormality on her brain scans."
An MRI confirmed the presence of a large infiltrative neoplasm involving the brain stem and cerebellum, and spreading along the cerebrospinal fluid (CSF) pathways to the lateral and third ventricles of the brain. "The bulk of the tumor was present in the posterior fossa, mainly the brain stem but also the cerebellum, and it had spread to the CSF fluid-filled cavities of the brain,carpeting the floor of the third ventricle and the walls of lateral ventricles," Dr. Sandberg says. "It was blocking the flow of CSF, preventing it from circulating and causing massively enlarged ventricles."
To treat the hydrocephalus and make a diagnosis, Dr. Sandberg performed a right frontal endoscopic tumor biopsy and third ventriculostomy, a minimally invasive alternative to shunt placement for the treatment of hydrocephalus. Both the biopsy and third ventriculostomy were performed via a single skin incision only a few centimeters long. The third ventriculostomy, which takes only a few minutes, allows fluid in the brain to bypass a blockage caused by the tumor and circulate normally. For selected patients,the procedure avoids insertion of a shunt, which is associated with many complications.
"The endoscopic third ventriculostomy was successful, and in total,we took 10 biopsies from different nodules," says Dr. Sandberg,whose major clinical interests include pediatric brain tumors, minimally invasive endoscopic approaches to brain tumors and hydrocephalus, congenital spinal anomalies, vascular malformations, spasticity and craniofacial disorders in children. "Andrea had no new deficits after surgery. To our surprise, the final pathology report was neurocytoma. Neurocytoma with widespread infiltration of the brain stem and cerebellum had not been previously reported."
Dr. Sandberg made the decision to treat Andrea conservatively with close follow-up because of the low grade of the tumor. Over the four years that have passed since her diagnosis, no additional treatment has been required, and repeated MRI scans have shown no change in tumor size.
"Andrea and her mother are really good people," Dr. Sandberg says. "She's a great kid with a very positive attitude who's leading a normal life. You don't have to be a neurosurgeon to look at her imaging studies and wonder why she's not seriously impaired. I'm particularly proud of this case because we were able to approach it in a minimally invasive way. Using an endoscopic approach we accomplished our two goals: we treated the hydrocephalus, and we made a diagnosis that allowed a thoughtful treatment plan."
"It's all about being positive and having faith in the process," Andrea says. "It's not easy for parents who know their child has a brain tumor. My mom and dad were distraught, but I took it with a smile. I said, 'I'm okay, I'm fine and we're going to get through it.'"
Today, Andrea is a sophomore studying psychology at Miami Dade College, with plans for a career in neuropsychology or child psychology. "She's an A student, and next year she'll be starting at Florida International University in Miami," her mother says. "When I think of Dr. Sandberg, I see an angel. That was my first impression of him, and it's the one I still remember today."