Variability in the size and shape of a cell or nucleus
Amicrograph showing cells with marked nuclear shape and size variation, a component of nuclearpleomorphism . Pleomorphism is a term used inhistology andcytopathology to describe variability in the size, shape andstaining ofcells and/or theirnuclei . Several key determinants of cell and nuclear size, likeploidy and the regulation of cellularmetabolism , are commonly disrupted intumors .[ 1] cancer progression and a feature characteristic ofmalignant neoplasms and dysplasia.[ 2] [ 3] benign cell types may also exhibit pleomorphism, e.g.neuroendocrine cells ,Arias-Stella reaction .
A rare type ofrhabdomyosarcoma that is found in adults is known aspleomorphic rhabdomyosarcoma .[ 4]
Despite the prevalence of pleomorphism in human pathology, its role in disease progression is unclear. Inepithelial tissue , pleomorphism in cellular size can induce packing defects and disperse aberrant cells.[ 5]
^ Schmoller, Kurt M.; Skotheim, Jan M. (December 2015)."The Biosynthetic Basis of Cell Size Control" .Trends Cell Biol .25 (12):793– 802.doi :10.1016/j.tcb.2015.10.006 PMC 6773270 PMID 26573465 . ^ Travis, W.D.; Brambilla, B.; Burke, A.P; Marx, A.; Nicholson, A.G. (2015).WHO Classification of Tumours of the Lung, Pleura, Thymus and Heart ISBN 978-92-832-2436-5 the original on March 21, 2015. ^ El-Naggar, A.K.; Chan, J.C.K.; Grandis, J.R.; Takata, T.; Slootweg, P.J. (23 January 2017).WHO Classification of Head and Neck Tumours ISBN 978-92-832-2438-9 the original on 2019-10-31. Retrieved2019-10-31 . ^ Okazaki, Mitsuyoshi; Tajima, Hidehiro; Ohbatake, Yoshinao (21 April 2020)."Pleomorphic rhabdomyosarcoma of the liver in an adult: a rare case report" .BMC Surgery .20 (1): 81.doi :10.1186/s12893-020-00742-7 PMC 7171846 PMID 32316960 . ^ Ramanathan, Subramanian P.; Krajnc, Matej; Gibson, Matthew C. (October 2019)."Cell-Size Pleomorphism Drives Aberrant Clone Dispersal in Proliferating Epithelia" .Developmental Cell .51 (1): 49–61.e4.doi :10.1016/j.devcel.2019.08.005 PMC 6903429 PMID 31495693 . 
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