KIT and adenocarcinoma: 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.