Minimally Invasive Tubular Approach for Occipital Condylar Biopsy and Resection

Occipital condyle syndrome describes the presentation of a patient with unilateral occipital headache and ipsilateral hypoglossal nerve palsy. The clinical significance of occipital condyle syndrome is that it is frequently the first sign of bony metastasis to the occipital condyle and can many times be discovered prior to the primary malignancy. Surgical approaches to the craniovertebral junction are inherently challenging and have traditionally involved far-lateral craniotomies, open posterior approaches, and transoral approaches. Few cases of minimally invasive surgical approaches specifically to the occipital condyle have been described.

We present the case of a 38-year-old African-American female with past medical history of breast cancer (DCIS, ER+, PR+, HER2-) status post right breast simple mastectomy and left breast modified radical mastectomy and treatment with letrozole and leuprolide 3 years prior to admission, who presented to an outside hospital with a two month history of headache localizing to the right occipital area, and right tongue deviation. Neurologic exam was notable for a right hypoglossal nerve palsy. MRI revealed a 1.3 cm × 1.1 cm heterogeneously enhancing mass within the right occipital condyle which was noted to be lytic on CT (image 1). After multidisciplinary discussion between the patient's oncologist and neurooncologist it was decided to pursue tissue diagnosis via an excisional biopsy. The patient was brought to the OR and placed in three-point cranial fixation in the prone position. A 3-cm paramedian incision was made on the right ~2.5 cm off midline at the level of C1. Sequential dilation using a tubular retractor system was performed under fluoroscopic guidance (image 2). Using a penfield #4 dissector, a subperiosteal plane was identified and carefully followed laterally and anteriorly until the condylar fossa was visualized (image 3). Once the posterior surface of the occipital condyle was seen, the cortex was entered (image 4) at which point tumor was immediately visualized and resected. Specimen was sent for pathology. A combination of pituitary rongeurs, curettes, and suction dissection was used to debulk the condylar mass while minimizing bony destruction. Operative time was 65 minutes and estimated blood loss was 5 cc. The patient was able to be discharged less than 24 hours after surgery.

We present the first case of a minimally invasive tubular retractor system-based approach for biopsy and resection of a breast metastasis causing occipital condyle syndrome. The majority of patients in the literature found to have isolated occipital condyle metastases have been treated with radiotherapy without surgical biopsy or intervention. Biopsy and resection with a plan to adjust chemotherapy limits the risks of radiation including development of radiation induced tumors which is small however not negligible. The biopsy results in this case were also significant as the final pathology was different from the outside hospital pathology report from the patient's original surgeries. The benefits of a minimally invasive approach to the craniocervical junction include decreased operative time, decreased blood loss, decreased postoperative pain, and decreased hospital length of stay.