Invasive Duct Carcinoma, Grade III with Normal Chromosome 17 CEP Number and Amplified TOP2A Gene. (A), Histologic section of the tumor, Hx&E stained (X400); (B), Immunostained slide showing high KI-67 LI about 85 %(X200); (C), Representative FISH image showing normal CEP17 copy number and amplified TOP2A gene (only 1 Aqua signal per nucleus for the chromosome, due to truncation of nuclei and 2-5 red signals for the gene). Red arrow points to nucleus with amplified TOP2A gene. Gene to chromosome ratio>2.