Histopathology of parasellar neoplasms

Histopathology of parasellar neoplasms: The anatomical and histological complexity of the parasellar region, as well as the presence of embryonic remnants, determine the huge diversity of parasellar neoplasms. Some of them are only located in the parasellar region, whereas others can occur elsewhere, within or outside the central nervous system. Their spectrum ranges from histologically benign and low grade malignant to high-grade malignant tumours. Although rare, metastases can pose differential diagnostic dilemmas. The severity of the clinical picture, the challenges of surgery and the risk of adverse sequelae related to surgery or radiotherapy make parasellar tumours interesting entities for the clinicians irrespective of their histological malignancy grade. Due to the different cell origin of parasellar tumours, the World Health Organisation classification system does not categorise them as a distinct group. Detailed criteria for classification and malignancy grading are presented in the classification systems covering central nervous system tumours, haematological malignancies, tumours of the soft tissue and bone. In the last years, molecular genetic features have been integrated into the diagnosis of several types of the parasellar tumours enhancing diagnostic accuracy and providing information of the value for targeting therapies. In this review, we will present histopathological and molecular genetic features, updated classification criteria, recent advances in the diagnostics and rationale for novel pharmacological therapies of selected types of parasellar neoplasms.