acinic cell adenocarcinoma /asin″ik/ [L, acinus, grape] , an uncommon low-grade malignant neoplasm that develops in the secreting cells of racemose glands, especially the salivary glands. The tumor consists of cells with clear or slightly granular cytoplasm and small eccentric dark nuclei. Also called acinar adenocarcinoma, acinous adenocarcinoma.