Extensive radiation therapy may seriously impair the nontumorous pituitary resulting in permanent hypopituitarism. It can also cause injury to adjacent structures such as the hypothalamus. A late side effect of sellar irradiation is the development of tumors in the sella region. These tumors become manifest many years, after irradiation. Some of these postirradiation tumors such as fibrosarcoma and osteosarcoma are malignant and can invade adjacent structures and cause the demise of the patient.
Many basic problems related to pituitary adenomas are unresolved.
Their solution has not only theoretical, but also considerable practical significance because it can markedly contribute to the treatment, cure and well-being of patients harboring a pituitary adenoma. Obviously, much more study is needed to understand better the development, clinicopathologic correlations, progression and treatment of pituitary tumors.