Cells can die as a consequence of being phagocytosed by other cells — a form of cell death that has been called phagotrophy, cell cannibalism, programmed cell removal and primary phagocytosis. However, these are all different manifestations of cell death by phagocytosis (termed ‘phagoptosis’ for short). The engulfed cells die as a result of cytotoxic oxidants, peptides and degradative enzymes within acidic phagolysosomes. Cell death by phagocytosis was discovered by Metchnikov in the 1880s, but was neglected until recently. It is now known to contribute to developmental cell death in nematodes, Drosophila and mammals, and is central to innate and adaptive immunity against pathogens. Cell death by phagocytosis mediates physiological turnover of erythrocytes and other leucocytes, making it the most abundant form of cell death in the mammalian body. Immunity against cancer is also partly mediated by macrophage phagocytosis of cancer cells, but cancer cells can also phagocytose host cells and other cancer cells in order to survive. Recent evidence indicates neurodegeneration and other neuropathologies can be mediated by microglial phagocytosis of stressed neurons. Thus, despite cell death by phagocytosis being poorly recognized, it is one of the oldest, commonest and most important forms of cell death.

细胞可能因被其他细胞吞噬而死亡，这种细胞死亡形式被称为吞噬作用、细胞同类相食、程序性细胞去除和原发性吞噬作用。然而，这些都是吞噬作用（简称“吞噬作用”）引起的细胞死亡的不同表现。被吞噬的细胞因酸性吞噬溶酶体内的细胞毒性氧化剂、肽和降解酶而死亡。 Metchnikov 在 1880 年代发现了吞噬作用引起的细胞死亡，但直到最近才被忽视。现在已知它会导致线虫、果蝇和哺乳动物的发育细胞死亡，并且对于针对病原体的先天和适应性免疫至关重要。吞噬作用引起的细胞死亡介导红细胞和其他白细胞的生理更新，使其成为哺乳动物体内最丰富的细胞死亡形式。针对癌症的免疫也部分由巨噬细胞吞噬癌细胞介导，但癌细胞也可以吞噬宿主细胞和其他癌细胞以求生存。最近的证据表明神经变性和其他神经病理学可以通过小胶质细胞对应激神经元的吞噬作用介导。因此，尽管吞噬作用引起的细胞死亡尚未得到充分认识，但它是最古老、最常见和最重要的细胞死亡形式之一。