Primary Gingival Squamous Cell Carcinoma With Secondary Extension Into the Maxillary Sinus, Orbit, and Skull Base: A Case Report.

Gingival squamous cell carcinoma (GSCC) is an uncommon oral malignancy that may mimic benign periodontal disease, often leading to delayed diagnosis and advanced stage presentation. We present a 68-year-old man with primary GSCC demonstrating extensive secondary invasion into the maxillary sinus, orbit, and skull base. He presented with progressive weakness, poor oral intake, cachexia, right facial numbness, and visual disturbances. His history was notable for a prolonged absence of medical and dental care due to financial barriers. Imaging revealed a large, destructive mass with orbital apex, cavernous sinus, and skull base involvement, consistent with aggressive perineural and intracranial spread, with regional metastasis to a level II cervical lymph node and distant osseous metastasis to the occipital bone. Given the extent of disease, the tumor was deemed unresectable and managed with systemic therapy, radiation, and corticosteroids for compressive optic neuropathy. This case highlights the aggressive potential of GSCC when diagnosis is delayed and emphasizes the critical role of early recognition and access to preventive care in improving outcomes.