歯原性腫瘍と嚢胞の組織分類

抄録

The revised second edition of “WHO Histological Typing of Odontogenic Tumours” was published in 1992, which attempts to update the first classification in the light of current progress in diagnosis and the relevance of tumor types to clinical and epidemiological features. The classification is of importance to standardize the criteria for scientific research and to facilitate collaboration among clinicians, pathologists and radiologists in the diagnosis. However, some exclusions of relevant lesions and their detailed descriptions made in the revision may cause confusion in differential diagnosis. This review refere to the major differences between the first and second edition of the WHO classification. Several revised lesions in the second edition were discussed with respect to their differential diagnosis. The major changes includea new group of benign odontogenic tumors, the addition of several new categories in odontogenic tumors and cysts, and the rearrangement of categories of cementum-forming lesions. The classification of tumors based on the molecular basis of developmental stage and / or the differentiation step of odontogenic tissues rather than histomorphological features alone may more precisely reflect the biological and clinical behaviors of the tumors. However, our knowledge in this area is limited. Differential diagnosis may still be problematic and requires experience that the low occurrence rate of odontogenic tumors is not likely to provide. A recently developed database on a computer network may be a powerful educational tool with respect to both scientific research and diagnostic practice.