With few reported cases, cystic hygroma is known to occur mainly in patients under the age of two years. Cystic hygroma can eventuate in any area; however, it mostly occurs in the cervicofacial area. If cystic hygroma occurs in this area, then the lesion may be related to the vital structures. Therefore, a complete surgical resection may be impossible and difficult to perform. This incident affects the high recurrence rate of cystic hygroma. The purpose of this report is to present a case of cystic hygroma occurring on the left side of the neck of a 47-year-old male patient as well as a review of literatures.

Ameloblastoma is an odontogenic tumor characterized by various sites of metastasis, malignant transformation, and a high recurrence rate over time. Ameloblastic carcinoma(AC) is the term reserved for an ameloblastoma with histologic evidence of malignancy in the primary tumor. AC is classified into two types: most ACs occur de novo, and only few cases of malignant transformation of ameloblastoma become apparent. Here, we report a case of AC, arising from recurrent acanthomatous ameloblastoma on the maxillary sinus, in a 60-year-old male patient. The mass was first diagnosed as acanthomatous ameloblastoma; subsequently, surgical curettage was performed thrice while partial maxillectomy was performed twice. On the fifth recurrence, the tumor was identified as AC.