Salivary gland neoplasia: an outcome of modified morphogenesis and cytodifferentiation.

Regeneration and replenishment of salivary tissues proceed in a manner analogous to stages in the embryonic development of salivary glands. The regenerative potential of the salivary unit resides in the reserve or stem cells of the intercalated and excretory ducts. Neoplastic development in salivary glands may be regarded as an epigenetic event, imposed by an ocogenic stimulus onto morphogenesis and cell differentiation. Depending on the level of differentiation of the reserve cell's progeny at the time of oncogenesis, the corresponding neoplasm can be poorly differentiated or anaplastic or as well differentiated as a histologically low-grade acinous cell carcinoma.