The c-kit protein has been considered as a helpful marker in distinction between ACC and other salivary gland tumors, which share morphological similarities, such as polymorphous low-grade adenocarcinoma.18,19 The negative stain found should be partially explained by the fact that the ACC arising in a previous PA probably displays a different immunoprofile and genetic abnormalities than ACC without PA association, perhaps owing to different mechanisms of carcinomatous initiation and progression, despite the similar histopathological aspects. This evidence concerns the gene KIT and tumor of salivary gland.