Histopathological features of malignant craniopharyngioma: Case report and literature review.

Malignant transformation in craniopharyngiomas is a very uncommon event and scarcely mentioned in the World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS). So far, there are only 34 reported cases. Aims We report an additional case in a 63-year-old woman who was diagnosed with craniopharyngioma 47 years ago. We reviewed the literature in order to define the histological features of malignant craniopharyngioma and its overlap with odontogenic tumors. Results Our case presented morphology of mixed odontogenic ghost cell/ameloblastic carcinoma. Analyzing all reported cases, 18 of them presented malignization as squamous cell carcinoma (SCC), 1 as odontogenic ghost cell carcinoma, 2 as ameloblastic carcinoma, and 10 cases were mentioned just as malignant craniopharyngiomas. Conclusion We concluded that SCC represented only half of the malignant cases, while the morphology of ~ 11% of them was comparable with ameloblastic or odontogenic ghost cell carcinomas and 28% lacked a specific histological diagnosis. Most cases were fatal, which makes it necessary to include the entity of malignant craniopharyngioma in the WHO Classification of Tumors of the CNS as a high-grade tumor defining its histological variability.