RESUMO
BACKGROUND: Morbus Ollier is characterized by the presence of multiple enchondromas (ie, benign intraosseous cartilaginous lesions). Although their manifestation in the limb bones is well described, only a few cases with ear, nose, and throat (ENT) involvement, primarily arising from the skull, have been reported. The malignant transformation toward slowly growing low-grade chondrosarcomas is the most severe form of progression. METHODS: We report a unique case of a 54-year-old patient with Ollier disease with an extensive nasal enchondroma apparently eroding the middle nasal concha and expanding to the lateral nasal wall that raised suspicion of malignant transformation. RESULTS: Radiological and histological features of enchondromas can be controversial and seem to have limited sensitivity to exclude low-grade malignancy. The clinical symptoms play a decisive role in differentiation between enchondromas and low-grade chondrosarcomas. CONCLUSION: Surgery remains the only effective solution in removing an enchondroma and preventing the tendency toward malignant transformation.