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Under metaplasia refers to a conversion of a differentiated tissue (epithelial or mesenchymal) or cell type to another. Metaplasia is partially reversible; if the irritation can be eliminated. It is a qualitative change in body cells, which initially does not result in a change in the number of cells.

In principle, metaplasia can occur in all tissues, but in practical medicine it is of particular importance for the epithelia .

An irreversible cell transformation is called anaplasia ; Transition of more highly differentiated cells into less differentiated cells.


Under normal circumstances all components of a tissue are in a balance between renewal and consumption of their cells (cell death) and their intercellular substances.

Metaplasia is a special form of cellular adaptation to the environment. Continuous mechanical, chemical or inflammatory stimuli, often in connection with changes in the environmental conditions or the cellular milieu, result in the replacement of a surface epithelium by another, mostly inferior epithelium; or to a changed, mostly inferior cell performance.

A direct metaplasia (transdifferentiation) is not possible, but starting from the stem cells (basal or reserve cells) of an epithelium, another, differently differentiated cell is formed.


A micrograph of Barrett's esophagus

Different forms are distinguished: squamous epithelial metaplasia, glandular metaplasia, intestinal metaplasia, gastric metaplasia.

  • myeloid metaplasia

Under pathological conditions (such as leukemia ), the spleen can resume the production of granulocytes and erythrocytes that takes place in it during embryonic development. This process is known as myeloid metaplasia .

Barrett's esophagus is a metaplastic transformation of the epithelium of the esophagus.

Individual evidence

  1. a b 1.4 Metaplasia - Article in the pathology script of
  2. ^ Karl Zilles, Bernhard Tillmann : Anatomie. 1st edition. Springer, Berlin / Heidelberg 2010, ISBN 978-3-540-69481-6 , p. 30.
  3. a b Theodor H. Schiebler, Horst-W. Korf: Anatomy: histology, history of development, macroscopic and microscopic anatomy, topography. 10., completely revised. Edition. Steinkopff 2007, ISBN 978-3-7985-1770-7 , p. 6.
  4. Renate Lüllmann-Rauch: Pocket textbook histology . 3rd, completely revised edition. Thieme, Stuttgart 2009, ISBN 978-3-13-129243-8 , p. 104.
  5. ^ Luiz Carlos Junqueira (author), José Carneiro (author), Manfred Gratzl (ed.): Histologie: Neue Approbationsordnung. 6th, new trans. revised Edition. Springer, Berlin 2004, ISBN 3-540-21965-X , p. 239.

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