Mounting evidence against current histogenetic concepts for salivary gland tumorigenesis.

Various morphological observations of salivary gland tumors are frequently used to support histogenetic concepts, such as the semipluripotential bicellular reserve cell hypothesis, for these tumors. Singularly, evidence in support of this hypothesis remains unavailable. Indeed, physiological evidence from studies of salivary glands have long existed proving the semipluripotential bicellular reserve cell hypothesis was incorrect. More recent studies reconfirm this and show that all cell types in these complex glands are quite capable of replication and, therefore, of being involved in tumorigenic processes. The demise of the bicellular reserve cell hypothesis is long overdue.