Show Main Menu +
This peripheral smear stained with Wright-Giemsa shows a cytotoxic lymphocyte, also known as a large granular lymphocyte. Cytotoxic T lymphocytes have more cytoplasm and purple granules within the cytoplasm. When cytotoxic T-cells interact with the target cells such as viral or cancerous cells, these granules are secreted. They will deliver lethal proteins called perforin and other cytotoxic molecules to the target cells in order to kill them. Cytotoxic T-cells can be of T-cell or NK-cell derivation.