| Popis: |
Publisher Summary This chapter presents a classification of pituitary tumors based on their functionality, invasiveness, and aggressiveness. Pituitary tumors, often called adenomas, are among the most frequent intracranial tumors after meningiomas and gliomas. From their epidemiology to their molecular aspects, pituitary adenomas represent a broad spectrum of disorders that can be analyzed and classified according to autonomous secretion, clinical aspects in diagnosis and treatment, pathology in terms of light microscopy (LM) and electron microscopy (EM) features, and special issues such as the clinical impact of aggressive pituitary adenomas or rare pituitary carcinoma cases. Pituitary adenomas can be classified as secreting tumors (such as growth hormone (GH), adrenocorticotropic hormone (ACTH), prolactin (PRL) in women, or the rare thyroid-stimulating hormone (TSH)-secreting adenomas) or clinically nonfunctional adenomas. The remaining pituitary adenomas, representing approximately a third, are clinically silent and are known as nonfunctioning pituitary adenomas (NFPAs), meaning that they only cause symptoms due to tumor growth. GH-producing adenomas represent 20% of pituitary tumors in surgical material, and they show no sex predilection. Corticotroph adenomas are the most frequent form (two-thirds) of the Cushing syndrome in adults, leading to the clinical and biochemical features known as Cushing's disease. |
