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1. Chemistry See polymorphism.
2. Biology The occurrence of two or more distinct forms, as of an organism during its life cycle or of cells of a certain type.

ple′o·mor′phic adj.


(ˌpliːəˈmɔːˌfɪzəm) or


1. (Biology) the occurrence of more than one different form in the life cycle of a plant or animal
2. (Chemistry) the occurrence of more than one different form of crystal of one chemical compound; polymorphism
ˌpleoˈmorphic adj


(ˌpli əˈmɔr fɪz əm)

1. the occurrence of two or more forms in the life cycle of an organism.
2. the ability of a microorganism to change shape under varying conditions.
ple`o•mor′phic, adj.

pleomorphism, pleomorphy

the existence of a plant or animal in two or more distinct forms during a life cycle. Also called polymorphism.pleomorphic, pleomorphous, adj.
See also: Biology
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.pleomorphism - (chemistry) the existence of different kinds of crystal of the same chemical compound
chemical science, chemistry - the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions
chemical phenomenon - any natural phenomenon involving chemistry (as changes to atoms or molecules)
dimorphism - (chemistry) the property of certain substances that enables them to exist in two distinct crystalline forms
2.pleomorphism - (biology) the appearance of two or more distinctly different forms in the life cycle of some organisms
biological science, biology - the science that studies living organisms
organic phenomenon - (biology) a natural phenomenon involving living plants and animals


n. pleomorfismo, cualidad de asumir o tener formas diferentes.
References in periodicals archive ?
Left: There is little pleomorphism, although nuclear contour irregularities, grooves, and folds are seen.
The stained smears were evaluated and diagnosed as ductal carcinoma of breast when there is definite features of malignancy like cellular dissociation, nuclear pleomorphism, nuclear abnormalities, absence of bare nuclei.
The key to the correct diagnosis lies in the nuclei; although the nuclei are not as pleomorphic as those seen in a classic chromophobe renal cell carcinoma, subtle irregularities in nuclear contours, subtle pleomorphism, and focal perinuclear haloes are usually present upon careful examination (Figure 2, A).
Ancient schwannoma (AS) is considered as a long-standing variant of schwannoma, histologically characterized by hemorrhage, hemosiderin pigmentation and pleomorphism of cells.
The central or paracentral area was determined by the operator and the automated cell analysis detected overall density, number of sides, and area of each cell as well as overall pleomorphism and polymegathism indices.
Under light microscopy, the tumors showed AMLs with predominant lipomatous and myomatous components, without nuclear pleomorphism and mitotic activity.
In our case, there was no histological evidence of malignancy, necrosis, atypical and typical mitotic cells and pleomorphism.
It is a 4-tiered system in which nucleolar prominence define grades 1 to 3 and extreme nuclear pleomorphism or sarcomatoid and/or rhabdoid differentiation define grade 4 tumors (Table 2) (Figure 3).
The tumour has the histopathological characteristics of a patternless pattern, a slight pleomorphism, and a composition of hypercellular and hypocellular sites.
Histopathological examination revealed group of cells composed of haphazard arrangement of a mixture of large epithelioid, plasmacytoid and spindle cells with increased nuclear cytoplasmic ratio, nuclear pleomorphism and several mitotic figures (Figure 2).
Numerous keratin pearls and few mitotic figures with cellular and nuclear pleomorphism and hyperchromatism were also seen.