Table 1.

Key points in the 5th edition of the WHO classification of tumors of the pituitary region

• The most important point is the recommendation that pituitary adenoma be renamed as pituitary neuroendocrine tumor (PitNET). The International Classification of Diseases for Oncology (ICD-O) behavior code is revised from “0” to “3,” which indicates a change from benign to malignant disease. Pituitary carcinoma is also changed to metastatic PitNET

• Adamantinomatous craniopharyngioma and papillary craniopharyngioma are distinguished as separate tumor types

• Pituitary blastoma has been listed in the WHO Classification of Endocrine Tumors since the 4th edition and in the Central Nervous System WHO Classification since the 5th edition

• Pituicytoma, granular cell tumors of the sellar region, spindle cell oncocytoma, and sellar ependymoma are grouped into the pituicyte tumor family in the 5th edition of the WHO Classification of Endocrine Tumors

• Poorly differentiated chordoma has been recognized as a subtype of chordoma with clinicopathological features characterized by loss of SMARCB1 expression and is newly listed in the 5th edition of the WHO Classification of Endocrine and Neuroendocrine Tumors