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Emigration theory

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A theory proposed by the German-Jewish pathologist, Julius Friedrich Cohnheim, in which the neoplasms originate from various cell rests (embryonal cells) believed to persist in various sites after the development of the foetal organs and tissues


Emigration theory is a theory proposed by Julius Friedrich Cohnheim. Cohnheim is a German-Jewish pathologist. He became an assistant at the pathological institute of Berlin University under Rudolf Virchow. One of his distinguished works as a pathologist was included in Virchow's "Archiv für Pathologische Anatomie und Physiologie und für Klinische Medizin" (xli.) Cohnheim's essay, "Ueber Entzündung und Eiterung,". 1 In this paper, he proposed that the emigration of the white blood cells is the origin of the pus. This notion of which he eventually proved was regarded as a great revolution in pathology.1

Emigration, in physiological sense, refers to the leaving of cells from one area to another. The act or process of cell migration is diapedesis. An example of cells capable of emigrating is the leukocytes. Leukocytes are white blood cells, which as opposed to red blood cells are nucleated and lack hemoglobin. The leukocytes are involved primarily in providing immune defense, protecting the body against pathogens and foreign particles. The leukocytes include neutrophils, eosinophils, basophils, monocytes, macrophages, and mast cells. The leukocytes may move across the endothelium towards the region where they are needed for their immunological function.


  • Cohnheims theory

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1 Singer, I. & Haneman, F. T. (n.d.). COHNHEIM, JULIUS. Retrieved from