Case Study Series: Mature Teratoma Cerebellopontine Angle
This case involves a previously normal child who, at 15 months old, presented with nystagmus, or abnormal eye movements. Her neurologist recommended she have an MRI, and the results showed large tumor in the posterior fossa compressing her brain stem.
This was one of the largest tumors I have ever seen. We initially did a biopsy since the lesion was so large and she was so young to see if there was a role for chemotherapy prior to surgery.
The biopsy revealed that the tumor was a mature teratoma (benign) with no malignant components but if we left it alone, it would continue to grow and compromise the rest of the brain function leading to severe developmental delays and ultimately, death.
These tumors fall under the category of germ cell tumors and the mature teratomas are not responsive to chemotherapy. Other types of germ cell tumors are more aggressive/malignant and often are treated with chemotherapy and then possible surgery. This tumor was not a mixed germ cell tumor but rather a pure mature teratoma. The only option in this case was a complete resection.
Given its location in the right cerebellopontine angle, we knew that the facial nerve would be permanently damaged once we attempted to do a complete resection. Because of this, we planned for a nerve graft to be placed in the facial nerve to re-animate her face during the resection.
Dr. Joni Doherty was the neuro-otologist for the surgery and we worked togeher on the case.
This child was taken back to surgery and Dr. Doherty began by drilling out the temporal bone and dissecting out the facial nerve. I then proceeded to resect the tumor. Once we had resected the tumor, the intracranial portion of the facial nerve was completely removed since it was involved in the tumor. Dr. Doherty then proceeded to do a nerve graft from the spinal accessory nerve to the facial nerve in the temporal bone.
The patient has done very well after surgery and is now one year out from her operation. Her facial nerve function is steadily improving but the nerve needs to be re-taught how to function again so the recovery process is long and challenging.
She did develop hydrocephalus and needed a ventriculoperitoneal shunt about 6 weeks after her surgery but developmentally she is on a normal track once again.