Septic thrombophlebitis and carotid occlusion due to invasive fungal sinusitis

17-year-old girl, with personal history of poorly controlled type-1 diabetes since she was nine, attended the emergency department complaining from one week right ocular pain and facial and lingual paresthesias. Physical exploration showed difficulty on righteye opening and ophthalmoplegia, progressive facial edema and erythema over the trigeminal region, and mild right-arm weakness. She had bad general condition, lowgrade fever and tachypnea. An unenhanced brain CT showed opacified right maxillary sinus and ethmoid cells, with reactive sclerosis. No signs of intracranial affectation. CT angiography showed filling defect on the right cavernous sinus and the right carotid internal artery, with adequate filling of intracranial branches due to collateral filling over Circle of Willis. Intracranial venous sinus were patent. All these findings suggested septic thrombophlebitis of the cavernous sinus with extension to ICA, due to aggressive sinusitis. Two days later, a cranial MRI was performed, showing major increase of the inflammatory changes extending to masticator and buccal spaces, the pterygomaxillary fossa, the orbit (with right exophthalmos) and the optic nerve, as well as restricted diffusion on brain parenchyma which suggest acute infarction and leptomeningeal enhancement showing leptomeningeal extension of the disease. The patient went on surgery, which confirmed invasive fungal sinusitis due to Mucor species, but could not avoid her decease the following day.

Acute fungal sinusitis is a lethal form of sinusitis that takes place mostly in diabetic (mainly due to Rhizopus, Rhizomucor and Mucor) and immunocompromised patients (Aspergillus in 80% of severe neutropenic patients). This case illustrates nicely many of the most important complication of invasive fungal sinusitis: - Local: affectation tends to be unilateral, with aggressive bone destruction of sinus wall that can rapidly extend to the orbit (orbital fat, proptosis, abscess formation) and neck soft tissues (pterygomaxillary fossa and neck spaces). - Cerebral: tends to extend to brain parenchyma, mainly with abscess formation or empyema. Leptomeningeal extension, as in this case, is more rarely seen, as it’s subtler and in early stages. - Vascular: bone destruction can cause cavernous sinus extension, with vein thrombosis and potentially dissemination to carotid artery, with cerebral infarction (as illustrated in the case). Treatment involves aggressive surgical debridement and systemic antifungals, but in spite of that the prognosis tends to be poor.

Invasive fungal sinusitis is an aggressive disease in diabetic and immunocompromised patients, which needs high clinical suspicion in order to make an early diagnosis and avoid complications that generally lead to patient’s death.

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