Extrachromosomal DNA DNA in a variety of different organisms. Extrachromosomal DNA Extrachromosomal DNA is any DNA that is found outside the nucleus of a cell. It is also referred to as extranuclear DNA or cytoplasmic DNA. Most DNA in an individual genome is found in chromosomes but DNA found outside the nucleus also serves important biological functions. In prokaryotes, nonviral extrachromosomal DNA is primarily found in plasmids whereas in eukaryotes extrachromosomal DNA is primarily found in organelles. Mitochondrial DNA is a main source of this extrachromosomal DNA in eukaryotes. The fact that this organelle contains its own DNA supports the hypothesis that
Hürthle cell cells with distinct cell borders. The cytoplasm of the oncocytes in Hürthle cell adenomas and carcinomas is characterized by an eosinophilic granular nature, which is commonly due to the oncocytes' high content of mitochondria. Some of these cells can contain up to 5,000 mitochondria, which fills the cytoplasm to the point of nearly excluding other organelles. This high amount of mitochondria is reported to be a result of mutations in the mitochondrial DNA. Some scientists have identified these mutations as deletions in the mitochondrial DNA of Hürthle cells found in neoplasms and Hashimoto's thyroiditis. Hürthle cell cancer can be separated