Disorders Involving the Jugular Foramen: A Histology-Driven Treatment Strategy

Background The jugular foramen (JF) is the anatomic connection between the endo- and the esocranium. It presents three different tissue layers: the brain parenchyma with a dural layer, the bone of the skull base, and the neurovascular structures at the interface with the neck. Primary tumors originating from the JF are class C jugular paragangliomas, schwannomas, and meningiomas. Tumors involving the JF from adjacent sites are moreover chondrosarcomas, chordomas, endolymphatic sac tumors, metastasis, and malignant tumors with perineural spread from the head and neck district. Surgery is often challenging, and aimed at the balance between the therapy purpose and the intrinsic morbidity of each surgical approach.

Methods Between 2012 and 2017, 21 continuous patients were submitted to JF tumor resection at a third referral center. Intraoperative parameters, outcomes, and surgical techniques were retrospectively analyzed. The infratemporal type A and type B approach, the petro-occipital, transsigmoid approach, the retroauricular-retro/infralabyrinthine petrosectomy with parapharyngeal space dissection, and the far-lateral approach were the preferred surgical corridors.

Results Eleven patients presented a lesion directly originating from the JF, among these, nine patients had a type C tympanojugular paraganglioma and two patients had a meningioma. Tumors from adjacent sites with secondary involvement of the JF were one facial nerve schwannoma, two endolymphatic sac tumors, one bilateral chondrosarcoma, three chordomas, and three adenoid cystic tumors with perineural spread. A complete tumor resection was performed in 13 cases, and the patients have no evidence of disease. Six patients presented a residual benign tumor at the JF, two patients died of the disease.

Discussion Surgery at the JF aims to tumor removal, balancing the foreseeable morbidity of the approach and of the pathology itself. The application of the oncological principle of histology dictating the approach involves different perspectives of therapy. Malignant tumors as chordomas, with aggressive osteolysis at the bony level of the JF, require a combination of wide surgical corridors and adjuvant radiotherapy, despite macroscopic tumor removal, as the microscopic infiltration of the surrounding skull base bone is rarely removed. Benign, slow-growing lesions such as tympanojugular paragangliomas induce a natural morbidity on the lower cranial nerves, which is better tolerated than the acute surgical morbidity. Under this aspect, lower cranial nerves function, tumor growth, and age of the patient are key factors in treatment algorithm of JF benign lesions. This should involve a continuum of options ranging from observation to radical removal, including a partial surgery targeted to the removal of tumor threatening the brain stem, the facial nerve or determining intractable bleeding from the external ear canal, and a deliberate incomplete surgery considered for growing tumors with still spared nerve function.

Conclusion The treatment of JF lesions deserves a balance between the natural history of the disease, the histological behavior, and the surgical morbidity. The extent of surgery and radiotherapy is dictated by the pathology and tumor’s and patient’s factors are balanced to tail the best treatment.