Transnasal Endoscopic Resection of a Pituitary Metastasis From a Tonsillar Squamous Cell Carcinoma (SCC): A Case Report and a Review of the Literature.

This article presents the first documented case of a 61-year-old patient who underwent radical transnasal transsphenoidal endoscopic resection of a pituitary metastasis from a squamous cell carcinoma (SCC) of the tonsils. Only two other cases of pituitary metastases in SCC have been described in the literature to date. The patient was diagnosed with p16 and human papillomavirus (HPV)-positive tonsillar SCC in June 2022. After initial radiotherapy and cisplatin-based chemotherapy, the patient had to undergo repeat surgeries due to local tumor recurrence. At that time, there was no evidence of metastatic disease. In August 2024, 26 months after the initial diagnosis, the patient presented to another institution with severe headaches, dizziness, nocturia, and pollakiuria. Laboratory tests revealed panhypopituitarism as well as diabetes insipidus. Magnetic resonance imaging (MRI) showed an intra- and suprasellar mass with increased F-fluoro-2-deoxy-D-glucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT). A transcranial biopsy was performed that confirmed the diagnosis of a pituitary metastasis. Since radiotherapy carried a significant risk of impacting the unaffected optical system and the effect of chemotherapy was unknown, the interdisciplinary tumor board decided on resection. The patient underwent an extended endoscopic endonasal approach for radical tumor removal. The postoperative course was uneventful, and the patient received adjuvant radiochemotherapy and pituitary hormone replacement. Postoperative chemotherapy and radiation led to progression of the underlying disease, and the patient had to be switched to best supportive care six months after surgery. This is the first case that reports the feasibility of a radical resection of a pituitary metastasis of SCC via the endoscopic endonasal approach. This paper reviews the risk factors, radiographic presentation, treatment, and follow-up of patients with pituitary metastases from oropharyngeal cancer.