An unusual case of complicated rhinosinusitis of the sphenoid sinus involving the cavernous sinus and skull base: Endoscopic sinus surgery and medical therapy

Abstract

Isolated sphenoid sinus diseases are generally asymptomatic and relatively uncommon with the potential for serious complications. Patients with this condition should be monitored closely and treated aggressively and either diagnostic or therapeutic intent is often indicated. In the management of a complex, life-threatening condition that involves many different fields of expertise, the otolaryngologist plays a key role in orchestrating different specialists and gaining direct access to the affected area, thus taking the first and essential step towards diagnosis and therapy. Because of the superiority of computed tomography in defining the bony margins and the superior soft tissue resolution of magnetic resonance imaging, these two techniques should be used in a complementary manner in the evaluation of isolated sphenoid sinus disease in addition to mapping the lesion better and identifying intracranial and intraorbital extent. We report an unusual case of isolated rhinosinusitis of the sphenoid sinus involving the cavernous sinus, pterygoid fossae and masticatory space in an immunocompetent patient.

Keywords: Sphenoid sinusitis; cavernous sinus thrombosis; fungal rhinosinusitis; isolated sphenoid sinus disease.

Figure 1.

Preoperative coronal CT scan, showing an enlargement of the right sphenoid sinus with overdevelopment and opacity of the lateral recess. Thickening and sclerosis of the bone surrounding the right sphenoid sinus, the pterygoid process (white arrow) and the orbital apex (white arrowhead) can be observed. Focal interruption of the foramen rotundum (CNV2) (small star) and of the sphenoidal lateral recess wall is also present (black arrow).

Figure 2.

Preoperative (a) coronal and (b) axial gadolinium-enhanced T1-weighted MRI shows soft tissue protruding through the breach in the lateral recess wall of the sphenoid sinus (black arrowhead), invading the right internal pterygoid muscles, the masticatory fossa (double small star) and the pterygopalatine fossa (single small star) and infiltrating the II (CNV2) (black arrow) and III (CNV3) (white arrow) trigeminal branches. Endocrianially, the tissue extended into the cavernous sinus surrounding the Gasser ganglion (double angled arrow). The cavernous carotid artery appears unobstructed. The MRI show marked hypointense signal on (c) axial T2-weighted into the lateral recess of the sphenoid sinus with inflamed mucosa at periphery (white arrow).

Figure 3.

Intraoperative view during endoscopic sinus surgery shows an erosion of lateral recess wall of the right sphenoid sinus (white arrow).

Figure 4.

Axial gadolinium-enhanced T1-weighted MRI after 12 weeks of therapy shows good pneumatization of the right surgical cavity and a sharp decline in contrast enhancement of the lateral recess of right sphenoid sinus (white arrow), masticatory fossa (double small star) and pterygopalatine fossa (single small star). A similar decrease can be appreciated in phlogistic alterations of the Gasser ganglion and the cavernous sinus (double angled arrow).