Myelomonocytic/monocytic lineage involvement is also a characteristic of
polysomy 8 cases.
Determining true HER2 gene status in breast cancers with
polysomy by using alternative chromosome 17 reference genes: implications for anti-HER2 targeted therapy.
Determination of HER-2 status and chromosome 17
polysomy in breast carcinomas comparing HercepTest and PathVysion FISH assay.
Two of these had
polysomy 17 and thus a false positivity by IHC18; whereas, the reasons for the other case could be due to one of the following reasons, viz.
Polysomy and supernumerary isochromosomes in the grasshopper Omocestus bolivari (Chopard).
Chromosome 17
polysomy: a unifying hypothesis underlying benefit from adjuvant anthracyclines?
Within this group, the new investigation determined that 25 patients (19%) had
polysomy (defined as 2.2 copies or more per cell) of chromosome 17.
(25-31) Given the evidence that some group 3 cases have true HER2 amplification rather than
polysomy for chromosome 17, particularly when the HER2 copy number is high, the Expert Panel ultimately favored continuing to classify these cases as HER2 positive unless the concurrent IHC result is clearly negative (0 or 1+).
A lung adenocarcinoma without ROS1 fusion showing (C) patchy ROSI IHC staining and (D) FISH exhibiting
polysomy but no evidence of rearrangement (original magnifications X200 [A and C] and X630 [B and D]).
HER2/neu overexpression has been linked with
polysomy of chromosome 17.