Figure 11. An Actinomyces-infected periapical pocket cyst affecting a human maxillary first premolar (radiographic inset). The cyst is lined with ciliated columnar (CEP) and stratified squamous (SEP) epithelia. The rectangular block in (a) is magnified in (c). The typical ‘ray-fungus’ type of actinomycotic colony (AC in b) is a magnification of the one demarcated in (c). Note the two black-arrowheaded, distinct actinomycotic colonies (AC in c) within the lumen (LU). Magnifications: (a) 20x, (b) 60x, and (c) 210x. (From Nair et al., 2002.)