Septic Thrombophlebitis of Multiple Dural Sinuses Extending to Bilateral Internal Jugular Veins due to Acute Sphenoid Sinusitis: A Case of Lemierre’s Syndrome

Lemierre's syndrome (LS) is a rare and potentially life-threatening condition characterized by septic thrombophlebitis within the head and neck region. The lack of a standardized definition in the literature contributes to its limited evidence base. LS presents with various clinical manifestations, often showing atypical features across different age groups. Early diagnosis of LS is challenging due to its nonspecific nature. Recent evidence highlights significant short- and long-term morbidity risks. Successful management requires a multidisciplinary approach and appropriate antibiotic therapy. While LS is commonly associated with oropharyngeal infections, it can also arise from non-oropharyngeal sources, complicating diagnosis and management. We present a case of LS secondary to acute isolated sphenoid sinusitis in an 86-year-old woman. Imaging revealed multiple metastatic septic thrombophlebitis, including bilateral cavernous, inferior petrosal, right transverse and sigmoid sinuses, and internal jugular veins. Blood cultures grew <i>Streptococcus intermedius</i>, and endoscopic sphenoidotomy identified a fungus ball, with cultures confirming <i>Streptococcus anginosus</i> and <i>Aspergillus fumigatus</i>. The patient demonstrated significant recovery with no complications at follow-up. This case illustrates a complex, multifocal pattern of septic thrombophlebitis, extending to multiple venous structures, highlighting the need for comprehensive imaging and a multidisciplinary approach in diagnosing and managing this rare complication. Early recognition of LS, even in the context of non-oropharyngeal infections, is crucial for optimal treatment and improved outcomes.