What is the treatment for paranasal mycetoma?

Treatment of Paranasal Mycetoma (Fungal Ball)

Surgical removal via endoscopic sinus surgery is the primary and definitive treatment for paranasal mycetoma, with systemic antifungal therapy generally not required for this non-invasive form of fungal disease. 1, 2

Surgical Management

Endoscopic sinus surgery (ESS) is the treatment of choice for paranasal mycetoma, as it allows complete removal of the fungal debris and restoration of sinus drainage. 1, 3

• The surgical goals include: complete removal of inspissated fungal material, debridement of inflamed mucosa, and widening of the sinus ostium to prevent recurrence 1
• ESS has demonstrated excellent outcomes with low morbidity and recurrence rates in this patient population 2
• The maxillary sinus is most commonly affected (approximately 80% of cases), followed by sphenoid, ethmoid, and frontal sinuses 2, 3
• Multiple sinuses may be involved simultaneously, requiring comprehensive surgical planning 2

Role of Antifungal Therapy

Systemic antifungal agents are NOT routinely indicated for paranasal mycetoma, as this represents a non-invasive fungal infection confined to the sinus cavity. 1

• Unlike invasive fungal sinusitis, mycetomas do not penetrate tissue and therefore do not require systemic antifungal treatment 1
• Postoperative topical antifungal therapy may be considered to facilitate mucociliary clearance after surgical opening of the affected sinus 1

Diagnostic Imaging

CT scanning with bone windows is essential for preoperative planning, as it demonstrates the characteristic hyperdense material within the sinus (from calcium and mineral deposits) and any associated bone erosion or neo-osteogenesis. 1

• MRI can also detect the ferromagnetic substances (iron, magnesium, manganese) present in fungal balls, providing high diagnostic sensitivity 3

Important Clinical Distinctions

Paranasal mycetoma must be distinguished from invasive fungal sinusitis, which requires entirely different management:

• Invasive fungal sinusitis requires immediate aggressive surgical debridement PLUS systemic antifungal therapy (voriconazole for aspergillosis, amphotericin B for mucormycosis) 1, 4
• Mycetoma (fungal ball) is a non-invasive process occurring in immunocompetent patients, requiring only surgical removal 1, 2
• Tissue samples obtained during surgery should be sent for culture AND histopathology without homogenization to preserve fungal architecture and distinguish Aspergillus from Zygomycetes 1

Postoperative Management

Long-term follow-up with nasal endoscopy is recommended to monitor for recurrence, though recurrence rates are low (approximately 7% in reported series). 2

• The total dose of any adjunctive therapy should be guided by extent of disease and postoperative endoscopic findings 5
• Widening of the sinus ostium during initial surgery helps prevent recurrence by maintaining adequate drainage 1

Special Considerations for Sphenoid Mycetomas

Sphenoid sinus fungal balls carry higher surgical risk due to proximity to critical neurovascular structures, including the internal carotid artery and optic nerve. 2

• Three deaths from intracerebral hemorrhage as surgical complications have been reported in sphenoid mycetoma cases 2
• Careful preoperative imaging and meticulous surgical technique are paramount for sphenoid lesions 3