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Large Lymphocytes and Reactive Lymphocytes

Large lymphocytes have abundant pale blue transparent cytoplasm. If you imagine putting a printed page behind the cell, the cytoplasm looks as though you could see through it to read the words. Although there are usually no cytoplasmic granules present, a few large well-defined azurophilic granules (lysozomes) can occasionally be seen. In this case, the cells would be called large granular lymphocytes. A large lymphocyte can be found in the upper image to the right.

Reactive, or atypical, lymphocytes are relatively fragile cells, and as a result can be squeezed out of shape by surrounding cells, giving them a scalloped appearance instead of a smooth cytoplasmic edge. The nucleus of the reactive lymphocyte is larger than that of the small lymphocyte, and is more irregular in shape. Sometimes it is rounded, oval or indented with a typical "stretched" appearance. A reactive lymphocyte can be seen in the lower image to the right.