Vacuoles are seen in cells; and there is an opinion that these may be a special kind of plastid: some vacuoles pulsate.
plastid plas·tid (plās'tĭd)
Any of several pigmented cytoplasmic organelles found in plant cells and other organisms, having various physiological functions, such as the synthesis and storage of food. Also called trophoplast.
One of the granules of foreign or differentiated matter, food particles, or waste material in cells.