Skull Base Osteomyelitis due to Granulomatous Mucormycosis in an Immunocompetent Host

This 75-year-old previously healthy nondiabetic male presented with a severe right-sided headache. Physical and neurologic examination was normal. The magnetic resonance imaging showed sphenoid sinusitis and skull base osteomyelitis (SBO). Endoscopic biopsy of the clivus showed granulomatous inflammation with broad aseptate hyphae. Potassium hydroxide mount and in-house fungal cultures were negative. Oral posaconazole was started, and the tissue was sent to a reference laboratory for cultures and molecular diagnosis. Cultures yielded Rhizopus arrhizus . Adequate posaconazole trough levels were achieved, and the headache was resolved. Antifungals were stopped after 3 months, and the patient remains well over a 2-month follow-up with no clinical or radiologic relapse. While there have been a few cases of Mucor SBO reported in literature in immunocompetent and nondiabetics, there have been none with no clinical findings and granulomatous inflammation.