Apoptotic pocket-like structures of the bulge of the terminal hair follicles of the human scalp.

Terminal hair follicles of the human scalp of all ages showed apoptotic pocket-like structures in the outer root sheath of the bulge area at anagen, but not telogen phase. The occurrence of these hole structures was roughly estimated in 15% of anagen terminal hair follicles of the human scalp. The size of these apoptotic pockets was variable, ranging from pin hole-like spaces to larger structures filled with homogeneous black materials. These unusual variations were often co-localized with apoptotic degenerations and exclusively present in the presumptive bulge of anagen terminal hair follicles where arrector pili muscles were seen in the vicinity. In fact, these vacuolated structures tended to be present on the side where the major part of the arrector pili muscles anchored.