keratin accumulating cell keratinocyte An epidermal cell which synthesizes keratin and undergoes a characteristic change as it move upward from the basal layers of the epidermis to the cornified (horny) layer of the skin. Successive stages of differentiation of the keratinocytes forming the epidermal layers are basal cell, spinous or prickle cell, and the granular cell. CL:0000312 TAO:0009158 teleost_anatomy