Case Study Series: Clival Chordoma
This child was 9 years old when I first met her. She presented with progressive weakness on the left side, a weak voice, swallowing difficulties and impaired balance. Her imaging showed a lesion (tumor) in the posterior fossa compressing the brain stem.
Our initial impression was that this tumor was most consistent with a clival chordoma. We discussed the treatment options, and my plan was for a multi-staged approach for the resection of the lesion. I chose this treatment because I did not think it was possible to safely resect the entire lesion via a single surgery.
We began by doing an endoscopic endonasal approach to debulk the tumor and achieved about a 60 percent resection through this approach. Her pathology confirmed this tumor was indeed a chordoma. These tumors are benign, but they are extremely aggressive locally.
The best treatment for this type of tumor is what is called an en bloc resection, which means the tumor is removed with a cuff of surrounding normal tissue without ever actually seeing the tumor. However, this treatment is not possible when it is located in the clivus/skull base for two reasons. First, it is not technically possible, because it is impossible to get that wide of an exposure. It is also not possible neurologically, because you cannot remove all the neural elements and blood vessels that the tumor touches.
That is why for clival chordomas the goal is to remove all of the tumor, then treat the tumor bed with high doses of highly focused radiation — in this case proton beam therapy. Therefore, she needed more surgery in order to remove the remainder of the tumor.
She subsequently underwent a right-sided far lateral skull base craniotomy to approach the tumor from the lateral trajectory. We removed almost all of the residual tumor from this approach.
We did have to go after a few residual spots where the tumor was still visible on imaging. These included disease in the spinal canal on the left side, as well as disease in the petrous bone. She had a left-sided spinal approach from the base of the skull to the third cervical vertebrae to remove the left-sided spinal disease. For the tumor in her petrous bone, which was smaller than a centimeter in size, she underwent further endoscopic endonasal surgery.
We were able to achieve a gross total resection while avoiding any neurological deficits. She is now completely normal neurologically. Her pre-op weakness resolved soon after the endoscopic endonasal procedure. She did have transient worsening of her swallowing difficulty after the far lateral skull base craniotomy, but that resolved quickly as well.
She is now awaiting her proton beam therapy. I don’t know if her tumor will recur, but we are all very excited about how well she has done so far. I will post follow-up images on a delayed basis after her radiation treatment.