SERPINC1 and Mastoiditis: The major etiological risk factors for identified cases includes genetic and acquired prothrombotic states, pregnancy, puerperium, infections (sinusitis, mastoiditis, meningitis), oral contraceptives, trauma, dehydration, inflammatory diseases, etc.1-3 In young women, sinus thrombosis is found to occur more commonly during the puerperium than during pregnancy.7 The genetically induced prothrombotic states includes Antithrombin III, protein C and S deficiency, mutation in factor V, prothrombin (20210GA) and homocysteinemia.