Molecular Developments in Parasellar Tumors and Potential Therapeutic Implications

The parasellar region is the anatomical area around the sella turcica that represents a crucial crossroad for important adjacent structures. Several distinct tumors can primarily originate from this area, the most common being meningiomas, gliomas, embryonal cell tumors, germ cell tumors, and craniopharyngiomas. In addition, a number of systemic and inflammatory disorders can also affect the parasellar region, most commonly involving the pituitary. These lesions have different pathologic characteristics and malignant potential according to the new World Health Organization CNS5 2021 classification. Signs and symptoms may be nonspecific and are mostly related to a mass effect on the surrounding anatomical structures and/or impairment of endocrine function, whereas the vast majority lack a secretory component. The mutational signature analysis based on advances in molecular techniques has recently enabled the identification of specific gene mutations or signaling pathway aberrations. These developments may serve as a powerful means to delineate the pathophysiology of these lesions and serve as a diagnostic, prognostic, and therapeutic tool, particularly for high-risk populations. Treatment options include surgery alone or in combination with radiotherapy, chemotherapy, and disease-specific medical therapy, in order to prevent recurrence or further tumor growth along with replacement of coexistent pituitary hormonal deficiencies. In this comprehensive review, we present the current state-of-the-art developments in the histopathology and molecular biology of parasellar lesions, which often represent a diagnostic and therapeutic challenge, that may be utilized by a dedicated multidisciplinary team for the diagnosis, monitoring, and treatment of these lesions.