Chondroma in the Area of the Spheno-Ethmoid Junction.

Chondroma in the area of the spheno-ethmoidal junction is very rare. A 29-year-old male patient with chronic rhinosinusitis with nasal polyps was arranged for a preoperative computed tomography scan, and a lesion was accidentally found in his spheno-ethmoidal junction and involved the skull base. Combined with MRI, the lesion was misdiagnosed as fungal sinusitis. However, no fungal lesions were found during the operation, and cartilage tissue was confirmed only after some bone was ground away under the guidance of a surgical navigation system. Our case indicates that chondroma is easily misdiagnosed as fungal sinusitis when it appears in the sinuses and should be carefully distinguished from fungal sinusitis. Moreover, when lesions involve the skull base, surgical navigation systems are useful in accurately locating lesions.