CK20positive

CK20positive refers to the expression of cytokeratin 20 (CK20) protein within cells, detected through immunohistochemical staining. Cytokeratin 20 is an intermediate filament protein primarily found in epithelial cells, particularly those lining the gastrointestinal tract, urothelium, and certain other specialized epithelia. Its presence is a valuable diagnostic marker in histopathology.

When a tumor is described as CK20positive, it means that cancer cells within the tumor exhibit positive staining for CK20. This finding can help in differentiating between various types of cancers. For instance, CK20 positivity is characteristic of adenocarcinomas of the gastrointestinal tract, such as colorectal cancer and gastric cancer, as well as transitional cell carcinomas of the bladder. It can also be seen in Merkel cell carcinoma, a rare but aggressive skin cancer.

Conversely, certain other epithelial tumors, like those arising from the lung, breast, or prostate, typically do not express CK20 and would be considered CK20negative. This differential expression allows pathologists to narrow down the potential origin of a metastatic cancer when the primary tumor site is unknown. Therefore, CK20 positivity serves as a crucial piece of information in the diagnostic process, aiding in accurate tumor classification and guiding subsequent treatment strategies.