We present the case of a 36-year-old patient with ameloblastoma of the maxillary sinus. The history of the patient was extraordinary with respect to the diagnosis of an extensive odontogenic cyst of this sinus with a maxillary wisdom tooth located far from the region of origin. Both cyst and tooth had been completely extirpated more than 10 years prior to the current tumor diagnosis. Diagnosis of ameloblastoma was based on routinely processed specimen and supported by immunohistochemical markers. Localization and extension of both cyst and neoplasm support the assumption that both entities arose from the same area. Long-term follow-up is recommended in the treatment of odontogenic cysts.
