Metastatic Oropharyngeal Squamous Cell Carcinoma to the Cavernous Sinus

The patient is a 69-year-old male who presented to the emergency department with diplopia and right eyelid ptosis. He noted the diplopia began about two months earlier but had become significantly worse in the preceding week as well as new inability to open the right eye. He also described right forehead numbness during this time but had no change in visual acuity, nasal symptoms, headache or other complaints.

On physical exam, the patient was found to have complete right ophthalmoplegia with no function of cranial nerves III, IV, and VI. He also had a complete upper eyelid ptosis. He also had numbness in the right V1 distribution.

His past medical history was only remarkable for HPV-positive squamous cell carcinoma of the right tonsil (T1 N2c M0) that was diagnosed six months earlier. He had undergone primary radiation with concurrent Erbitux that was completed a few weeks prior to the onset of his diplopia.

MRI of the head was performed, which showed a 2.8 × 2.7 cm, contrast-enhancing mass centered in the right cavernous sinus with encroachment on the posterior sphenoid sinus. The mass was surrounding the cavernous carotid artery and also extended into Meckel’s cave and foramen ovale. He also had a head MRI from two months prior at the initial onset of his diplopia, which revealed a small, nonenhancing lesion in Dorello’s canal. Given the small size and subtlety of this lesion, it was not noted on the initial radiology report but was identified on retrospective comparison of these scans.

He was taken to the OR for biopsy via endoscopic endonasal approach. There was discoloration of the right clival recess and the lesion had eroded the overlying bone. The mass was soft and several biopsies were taken for pathology, which revealed high-grade squamous cell carcinoma. His postoperative course was unremarkable. A PET-CT was performed, which showed increased FDG avidity in the right cavernous sinus as well as an FDG-avid lesion in the liver, which was biopsied to reveal metastatic squamous cell carcinoma as well. He underwent salvage proton stereotactic radiation therapy for palliation of his symptoms.

This patient had an unusual case of oropharyngeal squamous cell carcinoma metastasizing to the cavernous sinus. It is important to maintain a high index of suspicion in patients with a history of head and neck malignancy that present with unusual symptoms and signs, as this may represent progression or recurrence of their disease. These situations warrant detailed physical examination and possibly imaging to further investigate potential etiology. Very few cases of oropharyngeal squamous cell carcinoma metastasis to the cavernous sinus have been reported in the literature. However, in a patient with a history of malignancy, metastatic lesion should remain on the differential diagnosis even when occurring in unusual sites such as the cavernous sinus.

No conflict of interest has been declared by the author(s).