| ameloblastic adenomatoid tumour | A benign epithelial odontogenic tumour appearing radiographically as a well-circumscribed radiolucent-radiopaque lesion usually surrounding the crown of an impacted tooth in an adolescent or young adult; characterised histologically by columnar cells organised in a duct-like configuration interspersed with spindle-shaped cells and amyloid-like deposition that gradually undergoes dystrophic calcification. Synonym: adenoameloblastoma, ameloblastic adenomatoid tumour. (05 Mar 2000) |
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| ameloblastic fibroma | <tumour> A benign mixed odontogenic tumour characterised by neoplastic proliferation of both epithelial and mesenchymal components of the tooth bud without the production of dental hard tissue; presents clinically as a slow-growing painless radiolucency occurring most commonly in the mandible of children and adolescents. (05 Mar 2000) |
| ameloblastic fibrosarcoma | <tumour> A rapidly growing, painful, destructive, radiolucent odontogenic tumour that usually arises through malignant change in the mesenchymal component of a pre-existing ameloblastic fibroma. Synonym: ameloblastic sarcoma. (05 Mar 2000) |
| ameloblastic layer | The internal layer of the enamel organ. Synonym: enamel layer. (05 Mar 2000) |
| ameloblastic odontoma | <tumour> A benign mixed odontogenic tumour comprised of an undifferentiated component histologically identical to an ameloblastoma and a well differentiated component identical to an odontoma; appears as a mixed radiolucent-radiopaque lesion and presents clinically as an ameloblastoma. Synonym: odontoameloblastoma. (05 Mar 2000) |
| ameloblastic sarcoma | <tumour> A rapidly growing, painful, destructive, radiolucent odontogenic tumour that usually arises through malignant change in the mesenchymal component of a pre-existing ameloblastic fibroma. Synonym: ameloblastic sarcoma. (05 Mar 2000) |
| acinar carcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| acinic cell carcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| acinous carcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| adenoid cystic carcinoma | <tumour> A histologic type of carcinoma characterised by large epithelial masses containing round, glandlike spaces or cysts which frequently contain mucus or collagen and are bordered by a few or many layers of epithelial cells without intervening stroma, forming a cribriform pattern like a slice of Swiss cheese; perineural invasion and haematogenous metastasis are common; occurs most commonly in salivary glands. Synonym: cylindromatous carcinoma. (05 Mar 2000) |
| adenoid squamous cell carcinoma | <tumour> A malignant neoplasm consisting chiefly of glandular epithelium (adenocarcinoma), usually well differentiated, with foci of metaplasia to squamous (or epidermoid) neoplastic cells. Synonym: adenoid squamous cell carcinoma. (05 Mar 2000) |
| adenosquamous carcinoma | <tumour> A type of lung tumour exhibiting areas of clear cut glandular and squamous cell differentiation along with regions of the undifferentiated carcinoma. (05 Mar 2000) |
| adnexal carcinoma | <tumour> A carcinoma arising in, or forming structures resembling, skin appendages. (05 Mar 2000) |
| alveolar cell carcinoma | <tumour> A carcinoma, thought to be derived from epithelium of terminal bronchioles, in which the neoplastic tissue extends along the alveolar walls and grows in small masses within the alveoli; involvement may be uniformly diffuse and massive, or nodular, or lobular; microscopically, the neoplastic cells are cuboidal or columnar and form papillary structures; mucin may be demonstrated in some of the cells and in the material in the alveoli, which also includes denuded cells; metastases in regional lymph nodes, and even in more distant sites, are known to occur, but are infrequent. Synonym: alveolar cell carcinoma, bronchiolar adenocarcinoma, bronchiolo-alveolar carcinoma, bronchioloalveolar adenocarcinoma. (05 Mar 2000) |
| anaplastic carcinoma | <tumour> Carcinoma with absence of epithelial structural differentiation. (05 Mar 2000) |