Ghost cell odontogenic carcinoma arising in the background of a calcifying odontogenic cyst.

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm, representing 3% of all ghost cell lesions of the jaws. They can arise de novo or from a pre-existing calcifying odontogenic cyst (COC) or dentinogenic ghost cell tumour (DGCT). A systematic review of the literature reported only 12 cases of a GCOC arising from a pre-existing COC. This report highlights an additional case of a GCOC arising from a pre-existing COC after 3 years in an adolescent male. The patient initially presented with a painless swelling of the right mandibular corpus. Panoramic radiographic examination showed an expansive unilocular radiolucent lesion. After 3 years, the radiographic features appeared more aggressive with increased expansion and cortical perforation. A wide surgical resection was performed, whereby the lesion was diagnosed as a GCOC. Due to the rarity of these malignant neoplasms, limited information is available regarding their biological behaviour. One-year follow-up revealed no clinical signs of recurrence.