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.

Petroclival intravascular papillary endothelial hyperplasia with psammoma body-like structures.

Masson's tumor or intravascular papillary endothelial hyperplasia (IPEH) is considered a non-neoplastic lesion. It is probably an unusual exaggerated reorganization of a thrombus. IPEH may be present as a secondary lesion in hemangiomas. Symptomatic osseous hemangiomas are rare tumors. Few cases of clival and petrous bone hemangiomas have been described. None of them shows secondary IPEH. So far, there are only four reported cases of cranial bone IPEHs in the literature, two in the skull, one in the clivus and one in the petrous apex. The aim of this study is to report an additional case of osseous hemangioma with secondary IPEH of the petroclival region. We review the literature and describe the main clinical features of IPEHs and hemangiomas of the clivus and the petrous bone. Additionally, we report an unusual histological feature observed in our case of IPEH, the presence of psammoma body-like structures. This feature has been rarely mentioned previously in IPEH. We consider that IPEH should be included in the lesions that may present psammoma bodies to avoid misdiagnosing it as a tumor that commonly shows psammoma bodies, such as intraosseous meningioma or, less frequently, metastasis of thyroid or ovarian carcinoma.