Acute otitis media complicated by mastoiditis and otogenic transverse-sigmoid sinus thrombosis in an adult: a case report on infectious pathogenesis and multidisciplinary therapy.

Background: Acute otitis media is usually a self-limited bacterial infection; however, in rare cases, contiguous spread to the mastoid and adjacent dural venous sinuses may result in life-threatening intracranial complications. Otogenic transverse-sigmoid sinus thrombosis is uncommon in adults and represents a diagnostic and therapeutic challenge because its early presentation may be nonspecific and evidence guiding management remains limited. Case presentation: We report the case of a 32-year-old man with no relevant medical history who presented with a 3-week history of right-sided otorrhea and otalgia, with clinical worsening despite outpatient amoxicillin-clavulanic acid. Physical examination revealed purulent otorrhea, external auditory canal edema, a bulging tympanic membrane, postauricular erythema, tenderness, and a positive Jacques sign. Contrast-enhanced computed tomography demonstrated acute mastoiditis with erosion of the sigmoid plate and thrombosis of the right transverse-sigmoid venous complex extending into the ipsilateral internal jugular vein. Magnetic resonance venography confirmed absence of venous filling in the affected venous territory. The patient was managed using a stepwise multidisciplinary approach that included broad-spectrum intravenous antibiotics, anticoagulation with enoxaparin, myringotomy with ventilation tube placement, mastoidectomy, lateral sinus puncture, and drainage of a mastoid tip abscess. Microbiological cultures obtained after antibiotic exposure showed no growth. The patient had a favorable short-term clinical and otologic course, with mild residual conductive hearing loss at 1 month; however, postoperative vascular imaging was not available to objectively document venous recanalization. Conclusion: This case illustrates the pathophysiological continuum from acute otogenic infection to contiguous mastoid involvement, sigmoid plate erosion, presumed septic venous thrombosis, and potential intracranial extension. It also highlights the importance of early contrast-enhanced imaging, targeted venous assessment, antimicrobial escalation, surgical source control, individualized anticoagulation, and structured follow-up in adults with complicated otogenic infections. Because microbiological confirmation and postoperative vascular imaging were not available, the infectious and thrombotic interpretation should be considered clinically inferred rather than directly demonstrated.