- Small lymphocytes: These are the most common type in normal blood. They have a large, dense, round nucleus and thin basophilic cytoplasm and are capable of ameboid movement and the production of antibodies.
- Large lymphocytes: These are not very common in normal blood. The nucleus is indented, and cytoplasm is more abundant than in small lymphocytes. Azurophilic granules are frequently found in large lymphocytes; they are less commonly detected in small lymphocytes