I think the tumor samples have two copies of the chromosomes. But for constitutional samples, do they only have one copy of the chromosomes?
Constitutional samples do, as you surmised, refer to germ cells (sperm or ovum). Hence they have 1 copy of DNA instead of 2.
Tumours, as they acquire more mutations, often have aneuploidy, or different numbers of chromosomes, and can also have increased incidence of Xn chromosomes where X > 2. This is polyploidy for humans and organisms with normal 2n chromosomes.