Mitoses and cancer.

Mitoses are coupled to cell proliferation. In non-neoplastic cells they are usually symmetric and typical and lead to increase in cell number. Cancer cells are notorious for their asymmetric divisions, which are considered to reflect abnormalities due to disordered growth. The centrosome controls the mitotic activity and it has been proposed that centrosomal defects possibly contribute to carcinogenesis and aneuploidy of cancer cells. So far the atypical mitoses often seen in neoplastic cells are not considered unique. However careful observation of atypical mitoses in various neoplasms revealed that although they were indeed "atypical" they resembled each other within the same tumor and were different from those of other tumors. It is proposed that specific centrosomal alterations, which lead to a limited variety of atypical mitotic figures in each neoplasm, are not a random result but a distinct event that is possibly involved in carcinogenesis.