Foam cells and Epithelioid cells( note the spelling- its ..lioid)

Foam cells

1. Fat-containing macrophage.
2. Characteristic feature in the formation of atheromatus plaques.

Epithelioid cells.

1. In special situations, epithelial cells lack  a free surface.
2. Derived from progenitor mesenchymal cells.( such cells are present in testis,ovaries, pancreas, adrenal gland,...)
3. Epithelioid patterns are also formed by accumulations of connective tissue macrophages in response to certain types of injury and infections, as well as by many tumors derived from epithelium.