Craniofacial Resection for Skull Base Tumors

The symptoms of anterior skull base tumors are often subtle. Most patients experience reduced sense of smell and feel a constant stuffiness in the nose. Some may have nosebleeds. Frontal lobe signs may be present but unrecognized. Patients may tolerate their symptoms for a considerable length of time before seeking medical care. In most cases, an endoscopic examination by an otorhinolaryngologist for suspected rhinitis or polyps reveals the tumor. If so, a biopsy can usually be performed in the physician's office. Tumors may be benign (schwannomas, meningiomas) or malignant. The most common causes of malignant skull base tumors are esthesioneuroblastoma, neuroendocrine carcinoma, sinonasal melanoma, sinonasal undifferentiated tumor (SNUC), and squamous cell carcinoma.

Because skull base tumors can involve the nose and nasal passages and can invade and compress the brain, they are best managed through a coordinated team approach. As Richard S. Zimmerman, MD, a neurosurgeon at Mayo Clinic in Arizona, explains, "The reason that treatment must be highly integrated is that no one specialty crosses all the domains involved before, during, or after surgery."

Esthesioneuroblastoma stage 4 tumor

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Esthesioneuroblastoma stage 4 tumor

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Esthesioneuroblastoma stage 4 tumor

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Across Mayo Clinic's 3 campuses, the surgical teams always include a neurosurgeon and an otorhinolaryngologist. Depending on the case, an ophthalmologist and plastic surgeon also may be involved. When tumors cannot be fully removed by traditional surgery, stereotactic radiosurgery can be part of a staged approach. Neuroradiology is also integral. "We work hand in hand with neuroradiologists," says Ronald Reimer, MD, a neurosurgeon at Mayo Clinic in Florida. "They help in preoperative assessment of tumor burden, may perform embolization to lessen surgical blood loss, and help with intraoperative and postoperative MRI to ascertain degree of tumor resection." He adds, "Medical subspecialties help perioperatively as well. In patients with cancer, the oncologist and radiotherapist need to stage the patient and make sure no extensive tumor burden is present elsewhere in the body." Patients with malignant skull base tumors require lifelong follow-up, with imaging and endoscopic examinations approximately every 6 months.

At Mayo Clinic, surgical resection for skull base tumors typically involves a frontal craniotomy and a lateral rhinotomy. Sometimes neck dissection is necessary to remove involved lymph nodes. "There is a trend to remove the tumor endoscopically," says Michael J. Link, MD, a neurosurgeon at Mayo Clinic in Minnesota. "At Mayo, we don't often prescribe endoscopic tumor removal because, while taking the tumor out can be fairly straight-forward, the big issue is getting a good repair to prevent CSF leak and other potential problems. It may seem horrific to operate through the face, but in most patients, the scar is almost invisible in 3 months. The incision does not require a special type of closure and it heals well." Congenital deformities, trauma associated with facial fracture, encephalocele, and CSF leak are other conditions that, like anterior skull base tumors, may require craniofacial resection.

"The multispecialty practice at Mayo Clinic is designed to function optimally for these patients," notes Dr Zimmerman. "Patients benefit not only from the integrated medical record but from systems and procedures that encourage communication across subspecialties and streamline the necessary detailed cross-specialty planning and collaboration. We have a system that allows the physicians involved to make their calendars available for planning and performing the primary procedure and also for any complications that may arise afterwards. It is a completely patient-centered approach."