Imaging of pituitary tumors: an update with the 5th WHO Classifications —part 1. Pituitary neuroendocrine tumor (PitNET)/pituitary adenoma

AbstractThe pituitary gland is the body ’s master gland of the endocrine glands. Although it is a small organ, many types of tumors can develop within it. The recently revised fifth edition of the World Health Organization (WHO) classifications (2021 World Health Organization Classification of Central Nervous System Tumors and 2022 Worl d Health Organization Classification of Endocrine and Neuroendocrine Tumors) revealed significant changes to the classification of pituitary adenomas, the most common type of pituitary gland tumor. This change categorized pituitary adenomas as neuroendocrine tumors and proposed the name to be revise d to pituitary neuroendocrine tumor (PitNET). The International Classification of Diseases for Oncology behavior code for this tumor was previously “0” for benign tumor. In contrast, the fifth edition WHO classification has changed this code to “3” for primary malignant tumors as same to neu roendocrine tumor in other organs. Because the WHO classification made an important and significant change in the fundamental concept of the disease, in this paper, we will discuss the imaging diagnosis (magnetic resonance imaging, computed tomography, and positron emission tomography) of PitNET/pit uitary adenoma in detail, considering these revisions as per the latest version of the WHO classification.
Source: Japanese Journal of Radiology - Category: Radiology Source Type: research