Final answer:
In chronic lymphocytic leukemia, tumor cells commonly express the CD19 and CD5 cell-surface markers, which help in diagnosing and guiding treatment for the disease.
Step-by-step explanation:
In chronic lymphocytic leukemia (CLL), tumor cells typically show the presence of certain cell-surface markers that can help in diagnosing the disease.
CLL primarily affects B lymphocytes, which express unique markers different from T cells.
However, it's important to note that while T cells express either the CD4 marker or the CD8 marker, these are not the markers associated with CLL.
Instead, B cells in CLL typically express CD19 and CD5; the co-expression of these two markers can be characteristic of CLL.
Physicians use techniques such as immunohistochemistry to detect these antigens and thus identify the type of lymphoma.
These markers are essential because they assist in the diagnosis, prognosis, and can guide the treatment strategies for CLL.