Alternative definition : MMHCC: A focal atypical, non-invasive epithelial lesion with severe atypia and high
malignant potential. Focal increase of epithelium that contains cells with highly
atypical nuclei. Nuclear atypia corresponds to a nuclear score of 2 or three in the
Elston-Ellis grading system. These lesions have more severe atypia, higher mitotic
rate. Biological criteria is based on transplantation. High risk lesions grow in the
gland cleared mammary fat pad and frequently result in tumors and metastasis.;