A rare case of cavernous sinus thrombosis following oral squamous cell carcinoma - The etiology and management dilemma.

Intracranial cavernous sinus metastases of oral squamous cell carcinoma (OSCC) are rare, with a reported incidence of 0.4 %. Due to their extremely infrequent presentation the etiology and management modalities of such complications are not clearly represented in the literature. Here we present a case of a 58-year-old male diagnosed with OSCC of Right Lower Alveolus with underlying bone invasion, cT4aN1M0, Stage IV. He underwent Right Hemi-mandibulectomy with Modified Neck Dissection, Pectoralis Major Myocutaneous Flap, and 60 Gy/30# adjuvant radiotherapy. Six months later, the patient was diagnosed with recurrence involving the right infratemporal fossa with associated right cavernous sinus thrombosis. Immunohistochemistry block review showed PDL1 - Positive. The patient was subjected to Cisplatin and Pembrolizumab immunotherapy. After receiving 35 cycles of Pembrolizumab over a period of 2 years the patient is doing well with no recurrence.