In anatomical pathology, CD57 (immunostaining) is similar to CD56 for use in differentiating
neuroendocrine tumors from others. Using
immunohistochemistry, CD57 molecule can be demonstrated in around 10 to 20% of
lymphocytes, as well as in some
epithelial, neural, and
chromaffin cells. Among
lymphocytes, CD57 positive cells are typically either
T cells or
NK cells, and are most commonly found within the
germinal centres of
lymph nodes, tonsils, and the spleen. There is an increase in the number of circulating CD57 positive cells in the blood of patients who have recently undergone organ or tissue transplants, especially of the bone marrow, and in patients with
HIV. Increased CD57+ counts have also been reported in
rheumatoid arthritis and
Felty's syndrome, among other conditions.
Neoplastic CD57 positive cells are seen in conditions as varied as
large granular lymphocytic leukaemia,
small-cell carcinoma,
thyroid carcinoma, and neural and
carcinoid tumours. Although the antigen is particularly common in carcinoid tumours, it is found in such a wide range of other conditions that it is of less use in distinguishing these tumours from others than more specific markers such as
chromogranin and
NSE. == References ==