The most important function of epithelioid cells in tuberculosis is -

Epithelioid cells are activated macrophages and the function of macrophages is phagocytosis. So don't be misled into the wrong conclusion that the most important function of epithelioid cells is phagocytosis. Epithelioid cells appear to have enhanced abilities to secrete lysozyme and a variety of enzymes but decreased phagocytosis potential. The abundant pale cytoplasm reflects the presence of extensive rough endoplasmic reticulum (secretory function).