Long-Term Management of Chronic Invasive Skull Base Aspergilloma with Oral Voriconazole

Aspergillus infections of the paranasal sinuses are classified as invasive or noninvasive. The vast majority are noninvasive with good prognosis; however, invasive aspergillus can mimic malignant skull base neoplasms with bone destruction and orbital and intracranial extension, carrying significant morbidity and mortality. We present a case of invasive skull base aspergillus in a patient with diabetes presenting with multiple cranial neuropathies and weight loss.

A 61-year-old gentleman presented with 3 weeks of progressive dysarthria and dysphagia. He additionally reported a 20-pound weight loss spanning 2 months following a dental extraction complicated by acute sinusitis and prolonged antibiotic therapy. Medical history was significant for poorly controlled insulin-dependent diabetes mellitus with microvascular complications and coronary artery disease. Clinical examination revealed right aniscoria and ptosis, and right CN XI and XII weakness, right afferent pupillary defect, and decreased visual acuity. Endoscopy demonstrated fullness of the right lateral nasal wall. CT imaging revealed an infiltrative nasopharyngeal lesion involving the sphenoid sinuses, right orbital apex, jugular foramen, and petrous portion of temporal bone extending down toward longus coli on the right. MRI raised concern for skull base malignancy given encasement of the internal carotid artery and infiltration of the neural foramina of the skull base including foramen rotundum, ovale, lacerum, and jugular foramen.

He went to the operating room for endoscopic biopsy where right sphenoidotomy revealed a gray fibrous lesion. Histology revealed fungal hyphae, fibrosis, and chronic inflammatory cell infiltrate. Cultures grew aspergillus fumigatus. Given risks associated with attempt at subcranial excision of intracranial disease, a decision was made to proceed with conservative management including functional endoscopic sinus debridement and long-term antifungal therapy with voriconazole. Within 2 weeks of surgery, the patient demonstrated almost full recovery of hypoglossal and spinal accessory function with resolving ansicoria, ptosis, and visual acuity.

The patient has completed 28 months of treatment with oral voriconazole and has tolerated the drug well. His radiographic findings remain impressive. MRI continues to demonstrate the patient's known infiltrative nasopharyngeal lesion extending laterally to involve the right parapharyngeal space with persistent encasement of the internal carotid artery extending superiorly to infiltrate the central skull base and the clivus. The lesion is still characterized by T1 hypointensity with heterogeneous T2 hyperintensity with enhancement following contrast administration. Despite impressive radiographic findings, he remains neurologically intact.

Bone erosion and skull base invasion are often suggestive of a malignant mass originating in the paranasal and nasal cavities. This case illustrates that forms of invasive fungal disease may mimic malignant skull base processes. Given the rarity of this process, there are limited data to help guide otolaryngologists in the management of invasive skull base aspergillus. Data are reported in scattered case reports with little to no consensus regarding management. To the best of our review of the literature, less than 20 cases of invasive skull base aspergillus have been reported. Our case illustrates that conservative surgical management with long-term antifungal therapy can be well tolerated and lead to clinical stabilization. We also plan to present data on four additional patients treated at our institution for chronic invasive aspergillus.