Other Sellar and Parasellar Lesions

The sella turcica is an anatomically complex area that contains the pituitary gland. Pituitary gland tumors are the most common neoplasms of the sellar region and represent approximately 10–15% of all brain tumors. However, several lesions, including tumoral (both benign and malignant), vascular, inflammatory, and infectious diseases may affect this area, mimicking pituitary neoplasms. Unlike pituitary tumors, clinical presentation of other sellar lesions is more commonly related to mass effects to nearby structures or to compression/invasiveness of the pituitary stalk or gland (i.e., headache, visual defects, diabetes insipidus). Differential diagnosis of sellar lesions mainly relies on magnetic resonance imaging (MRI), which should be interpreted by radiologists skilled in base skull imaging. The treatment of the lesions located in these areas is challenging because of their heterogeneous histology and complex anatomical location. Surgery, more specifically the transsphenoidal approach, is often the main treatment for many sellar lesions as it allows a pathologic analysis and complete or partial tumor removal. Due to the proximity of critical structures and the risks of side effects related to the procedure, a radical surgical resection is often not achievable. Therefore, a multimodal approach, including also radiosurgery (SRS), radiation therapy (RT) and medical therapy is crucial. In this chapter, we provide an overview of nonadenomatous sellar lesions focusing on epidemiology, new pathological features, diagnosis, available treatment, and prognosis.