Clival inflammation with cavernous sinus thrombophlebitis and orbital subperiosteal abscess--case report.

A 64-year-old woman presented with a very rare case of three infectious lesions, cavernous sinus thrombophlebitis, clival inflammation, and orbital subperiosteal abscess (SPA), manifesting as abducens palsy. An isolated non-specific mass in upper clivus was initially suspected to be derived from paranasal sinusitis. The clival lesion was approached by an endonasal transsphenoidal route and diagnosed as inflammation. However, progressive enlargement of an orbital mass was recognized, with eyelid erythema and swelling. Magnetic resonance imaging showed massive paranasal sinusitis and an intra-orbital mass, which was proved to be an orbital SPA by open surgery. Cavernous sinus thrombophlebitis might have been caused by primary paranasal sinusitis, and the origin of orbital cellulitis was suspected to be cavernous sinusitis based on the preoperative radiological findings. These unusual lesions should be kept in mind as one of the differential diagnoses.