adamantinoma


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ameloblastoma

 [ah-mel″o-blas-to´mah]
a locally invasive, highly destructive tumor of the jaw; called also adamantinoma.
pituitary ameloblastoma craniopharyngioma.

ad·a·man·ti·no·ma

(ad'-ŏ-man-ti-nō'mă),
1. A low-grade malignant tumor of long bones (predominantly tibia) marked by a proliferation of nests of basaloid cells with palisading at the periphery. Compare: ameloblastoma.
2. A rare, slow-growing but locally aggressive tumor; its histogenesis remains controversial. Approximately 200 cases have been reported since it was first described in 1913. The tumor occurs almost exclusively in the long bones; tumors in the tibia account for more than 80% of cases. The diaphysial region is the area most commonly affected. The histiologic features of adamantinomas have many variations that are present not only among patients but also among different areas of the same tumor. Metastases occur in approximately 15-20% of patients and typically appear in the lungs and local lymph nodes.

adamantinoma

/ad·a·man·ti·no·ma/ (ad″ah-man″tĭ-no´mah) ameloblastoma.

adamantinoma, adamantoblastoma

adamantinoma

An extremely rare, generally indolent malignant epithelial tumour, which arises almost exclusively in the tibia or fibula in the second to fifth decade in life.

Clinical findings
Swelling, pain, developing over months to years.

Imaging
Eccentric, well-circumscribed, and lytic lesion on plain films.

DiffDx
Osteofibrous dysplasia, fibrous dysplasia, aneurysmal bone cyst, chondromyxoid fibroma, chondrosarcoma.

Management
Wide resection or amputation.

Prognosis
Excellent; overall survival is 85% at 10 years, but lower without adequate margins. Metastases are rare at presentation but may occur in up to 30% of patients during the disease course.

am·e·lo·blas·to·ma

(am'el'ō-blas-tō'mă)
A benign odontogenic epithelial neoplasm; it behaves as a slowly growing expansile radiolucent tumor, occurs most commonly in the posterior regions of the mandible, and has a marked tendency to recur if inadequately excised.
[ameloblast + G. -oma, tumor]

adamantinoma (adəman´tinō´mə),

adamantinoma

see ameloblastoma, acanthomatous epulis.
References in periodicals archive ?
Bir calismada izlemde tekrarlanan biyopside adamantinoma saptanmasi nedeniyle butun osteofibroz displazi tanili olgulara ekstraperiostal eksizyon onerilmektedir (11).
Background: Adamantinomas are extremely rare, locally aggressive and/or malignant lesions composed of epithelial-like cells in a dense fibrous stroma.
Conclusions: In general, adamantinomas have a varied radiographic appearance but usually present as expansile, multilocular, lytic lesions without periostitis.
Grade 1 (Low Grade) Low-grade central osteosarcoma Parosteal osteosarcoma Adamantinoma Grade 2 Periosteal osteosarcoma Grade 3 (High Grade) Ewing sarcoma/PNET Conventional osteosarcoma Telangiectatic osteosarcoma Mesenchymal chondrosarcoma Small cell osteosarcoma Secondary osteosarcoma High-grade surface osteosarcoma Dedifferentiated chondrosarcoma Dedifferentiated chordoma Malignant giant cell tumor
Adamantinomas tend to have a low-grade clinical course, but that is variable.
Those most commonly encountered include epithelioid vascular lesions (ie, hemangioma, hemangioendothelioma, and angiosarcoma), adamantinoma, epithelioid osteoblastoma, epithelioid osteosarcoma, chordoma, and epithelioid chondroblastoma.
To early pathologists, the admixture of epithelioid islands with basal palisading and spindled stroma recalled the histologic appearance of odontogenic adamantinoma of the jaw (ameloblastoma).
These 2 populations are also seen in differentiated adamantinoma (41) and osteofibrous dysplasia (OFD) although with a significantly reduced epithelial component: Differentiated adamantinoma displays scattered strands of epithelial cells distributed in a fibro-osseous matrix, whereas OFD has this same background with only rare epithelial cells detected by immunohistochemistry (Figure 6, C).
Several histologic variants of classic adamantinoma have been described including tubular, basaloid, squamous, and spindled variants.
Our understanding of the relationship among classic adamantinoma, differentiated adamantinoma (osteofibrous dysplasia-like adamantinoma), and OFD continues to evolve.
It has been suggested that the increased spindled component and diminished epithelial presence in differentiated adamantinoma reflects regression of classic adamantinoma.
Distribution of extracellular matrix components in adamantinoma of long bones suggests fibrous-to-epithelial transformation.