Lymphocytes vary greatly in size (8-20µm dia) and in nuclear and cytoplasmic character.
The small lymphocyte (8-10 µm dia) has a round-oval nucleus with dense clumped "smudgy" chromatin, high nucleus/cytoplasm ratio; no visible nucleolus. The cytoplasm is thin, basophil and non granular in small lymphocytes.
Larges lymphocytes may be 15-20µm (dia) and have a more abundant hyalin to basophilic cytoplasm.
Reactive lymphocytosis.