Endoscopic Approach of Metastatic Renal Clear Cell Carcinoma in Infratemporal Fossa

Representing 2 to 3% of adult cancers, renal cell carcinoma (RCC) accounts for 90% of renal malignancies and affects one and a half times more men than women. Clear cell RCC is the most common type. It is the third most common cancer of the genitourinary tract, following prostate and bladder tumors. At diagnosis, one-third of the patients usually have distant metastases. The most common sites are lungs (50%), bones (33%), skin (11%), liver (8%), and brain (3%). In this article, we report a case of metastatic RCC in infratemporal fossa (ITF), an unusual site of dissemination which was treated with endoscopic endonasal approach (EEA).

A nonsmoker 69-year-old male was presented with a history of left nephrectomy for RCC in 2001. He was subsequently diagnosed with multiple metastases. The patient underwent right lung metastases resection, right adrenal gland metastases resection, right cuboid bone metastases radiosurgery, and left maxillary sinus partial resection in 2018. Magnetic resonance imaging (MRI) performed for clinical follow-up detected suspicious left ITF lesion after 18 years of primary tumor treatment. Positron emission tomography with 18F-fluorodeoxyglucose (PET 18F-FDG) images corroborated the hypothesis of tumor metastases, showing radiotracer uptake in the left ITF region. The patient underwent multiple lines of systemic therapy (e.g., sunitinib, immunotherapy, and axitinib). We chose to perform EEA of the left ITF lesion for tumor resection. Histopathological study and immunohistochemistry confirmed the diagnosis of metastatic clear cell RCC.

Late recurrence of RCC several years after initial treatment may occur. But metastatic spread of RCC to the head and neck region is rarely seen. Such metastases can be observed in approximately 15% of cases, almost always associated with other lesions in other common sites. The main goal of the ITF surgery was the resection of the metastatic lesion for subsequent treatment plan with radiotherapy to the resected cavity. The close proximity of the ITF to the intracranial structures, orbit, paranasal sinuses, nasopharynx, and the facial area demands careful planning of surgical excision. Several ways of approaching the ITF have been described, such as the orbitozygomatic approach, midfacial degloving, and the maxillary swing. However, in selected cases, EEA may provide lower morbidity, shorter recovery time and induce less physiological impact compared with the techniques described above.

Patients previously diagnosed with RCC and who subsequently underwent surgical resection, the possibility of metastatic tumor should always be considered as a differential diagnosis when a solitary lesion develops on the head and neck region, even long time after primary surgery. Endoscopic endonasal approaches to the skull base allow excellent visualization, eliminate or significantly reduce the need for craniofacial soft tissue dissection, skeletal alteration and brain retraction for tumor access. For well-selected cases and appropriate adjuvant therapy, endoscopic resection results in acceptable oncological outcomes.