A psammoma body is a round collection of calcium, seen microscopically. The term is derived from the Greek word ψάμμος (psámmos), meaning 'sand'. A psammoma body is a round collection of calcium, seen microscopically. The term is derived from the Greek word ψάμμος (psámmos), meaning 'sand'. Psammoma bodies are associated with the papillary (nipple-like) histomorphology and are thought to arise from,