anaplasia


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Related to anaplasia: metaplasia

anaplasia

 [an″ah-pla´zhah]
loss of differentiation of cells and their orientation to each other, a characteristic of tumor cells; called also dedifferentiation and undifferentiation.

an·a·pla·si·a

(an'ă-plā'zē-ă),
Loss of structural differentiation, especially as seen in most, but not all, malignant neoplasms.
Synonym(s): dedifferentiation (2)
[G. ana, again, + plasis, a molding]

anaplasia

(ăn′ə-plā′zhə)
n.
Reversion of cells to an immature or a less differentiated form, as occurs in most malignant tumors.

anaplasia

A state in which a malignant cell or tissue has undergone structural or functional dedifferentiation to the point where its lineage and/or tissue of origin cannot be determined with complete certainty. Anaplastic tumours usually have high mitotic activity and bizarre cellular morphology.

an·a·pla·si·a

(an'ă-plā'zē-ă)
Loss of structural differentiation, especially as seen in most, but not all, malignant neoplasms.
Synonym(s): dedifferentiation (2) .
[G. ana, again, + plasis, a molding]

anaplasia

Loss of the cellular microscopic features which distinguish one type from another. Anaplastic cells become smaller and simpler in structure and no longer combine to form recognizable tissues. Anaplasia is a common feature of cancer and, in general, the greater the anaplasia the more malignant and dangerous the tumour.

anaplasia

the reversion of cells to a more undifferentiated form.

an·a·pla·si·a

(an'ă-plā'zē-ă)
Loss of structural differentiation, especially as seen in most, but not all, malignant neoplasms.
Synonym(s): dedifferentiation (2) .
[G. ana, again, + plasis, a molding]
References in periodicals archive ?
Anaplasia in pilocytic astrocytoma predicts aggressive behavior.
Microscopically; mucosa revealed diffuse urothelial dysplasia with loss of polarity, nuclear atypia; and carcinoma in situ with irregular nuclear crowding, nuclear anaplasia and mitosis, involving entire thickness of the epithelial layer.
He describes how gene mutations are not powerful enough to cause cancer; how cancer is initiated and why progression takes years or decades; and the global or macroscopic characteristics that identify cancer: anaplasia, autonomous growth, metastasis, abnormal cell morphology, DNA indices from 0.5 to over 2, genetic instability, and the high level of membrane-bound and secreted proteins responsible for invasiveness and loss of contact inhibition.
The animals showed a marked degree of hyperplasia with mitotic figure in the cells of stratum granulosum of epidermis and fibrocytes of the dermis, extensive anaplasia and malignant changes in acini and ducts of the mammary gland.
Histologically, diffuse anaplasia, PAS positive-DR hyaline globules and variable myxoid change.
Prognostic histology may be divided into favourable histology (triphasic Wilms' tumour and cystic, partially differentiated nephroblastoma) and unfavourable histology (focal or diffuse anaplasia, and cells that are more abnormal and appear bizarre with large and distorted nuclei).
Histologically, these tumors usually demonstrate definitive anaplasia, although sometimes the distinction between a periosteal chondroma and low-grade chondrosarcoma is difficult or indeterminate.
Anaplasia with cell pleomorphism and varying degrees of mitotic activity are characteristic for all malignant variants except the dendritic and whorled types (WEISS & FRESE, 1974).
Nevertheless, a few studies have documented minor his top a tho logical differences between AIDS-associated KS and non-HIV associated KS cases [14-16]: lesional cell mitoses and cellular anaplasia are surprisingly more common in HIV-negative patients, whereas KS lesions in HIV-positive patients tend to display more extensive dissecting vessels.
Grade III (anaplastic) meningiomas are characterized by anaplasia, brain invasion, and [greater than or equal to] 20 mitoses per 10 HPF or are of the rhabdoid or papillary subtypes (Perry et al., 1999).
Las evaluaciones histopatologicas microscopicas permitieron revelar la presencia de tejido neoplasico maligno poco diferenciado de tipo linfoide, con predominio de linfocitos B con alto grado de anaplasia y areas de necrosis con hemorragias, ratificando el diagnostico de linfosarcoma multicentrico: Las celulas neoplasicas tenian escaso citoplasma, nucleos hendidos e hipercromaticos en conjunto con linfocitos pleomorficos y elevado indice mitotico; tambien se encontro celulas gigantes multinucleadas y necrosis, observandose un variado patron histologico en algunas areas del tejido tumoral (FIGS.