The nuclear DNA content of lobular neoplasia of the mammary gland.

Twelve cases of lobular neoplasia and three cases of invasive lobular carcinoma of the breast were examined by Feulgen microspectrophotometry. Two different ranges of nuclear DNA values were observed. Eight cases of lobular neoplasia fell within the diploid range and the four remaining cases within the diploid to tetraploid range, while the three cases of invasive lobular carcinoma showed a DNA distribution between the diploid and tetraploid range. Cytophotometrically, lobular neoplasia with diploid DNA values can be considered to represent a precancerous condition, whereas lobular neoplasia with diploid to tetraploid values are regarded as a more advanced stage of an non infiltrating carcinoma still confined to the performed spaces.