Rhino-Orbital Hyalohyphomycosis - A Rare Presentation in an Immunocompetent Host

Hyalohyphomycosis is an opportunistic infection of the subcutaneous tissue caused by hyaline fungi Hyphomycetes that form septate hyphae within tissue. Immunocompromised states and tropical climates are the main predisposing factors. Rhino-orbital hyalohyphomycosis involving the paranasal sinuses and orbit in an immunocompetent host is a very rare presentation. We report the case of a 27-year-old male crop surveyor who presented with left-sided proptosis and double vision. Based on clinical evaluation and imaging studies-contrast enhanced tomography CECT and magnetic resonance imaging MRI of the paranasal sinuses and orbits - the findings were suggestive of an orbital pseudotumour or fungal mass such as mucormycosis. The patient underwent endoscopic sinus surgery with excision of the orbital mass via Denkers approach under general anaesthesia. Histopathological examination confirmed the diagnosis of hyalohyphomycosis. Postoperatively the patient was treated with anti-fungal medication Itraconazole and advised regular nasal saline irrigation. Although rare in immunocompetent individuals rhino-orbital hyalohyphomycosis should be considered among the differential diagnoses for unilateral intraorbital mass or proptosis.