Pleomorphism (cytology)

Not to be confused with Pleomorphism (microbiology).

Pleomorphism is a term used in histology and cytopathology to describe variability in the size, shape and staining of cells and/or their nuclei. Several key determinants of cell and nuclear size, like ploidy and the regulation of cellular metabolism, are commonly disrupted in tumors.^[1] Therefore, cellular and nuclear pleomorphism is one of the earliest hallmarks of cancer progression and a feature characteristic of malignant neoplasms and dysplasia.^[2][3] Certain benign cell types may also exhibit pleomorphism, e.g. neuroendocrine cells, Arias-Stella reaction.

A micrograph showing cells with marked nuclear shape and size variation, a component of nuclear pleomorphism.

A rare type of rhabdomyosarcoma that is found in adults is known as pleomorphic rhabdomyosarcoma.^[4]

Despite the prevalence of pleomorphism in human pathology, its role in disease progression is unclear. In epithelial tissue, pleomorphism in cellular size can induce packing defects and disperse aberrant cells.^[5] But the consequence of atypical cell and nuclear morphology in other tissues is unknown.

See also

• Anaplasia
• Cell growth
• Cytopathology
• Giant cell carcinoma of the lung
• Nuclear atypia

References

1. 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.
2. Travis, W.D.; Brambilla, B.; Burke, A.P; Marx, A.; Nicholson, A.G. (2015). . Lyon: International Agency for Research on Cancer. ISBN 978-92-832-2436-5. Archived from the original on March 21, 2015.
3. El-Naggar, A.K.; Chan, J.C.K.; Grandis, J.R.; Takata, T.; Slootweg, P.J. (23 January 2017). . Lyon: International Agency for Research on Cancer. ISBN 978-92-832-2438-9. Archived from the original on 2019-10-31. Retrieved 2019-10-31.
4. 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.
5. 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.