Hamartom Q85.91

Congenital or later manifesting malformations that develop due to abnormal compositions of structures normally found in a tissue (e.g. nevus sebaceus; e.g. cartilage proliferates in the bronchial wall). In contrast to neoplasia, their growth is not autonomous, but goes in parallel with the growth of the surrounding tissue.

The term " nevus", as a hamartoma of the skin, is only used in dermatological terminology. Various authors define the term "capillary nevus" exclusively as a post-zygotic mosaic in order to establish a clear etiopathogenetic classification.

Hamartomas occur particularly frequently as malformations of blood vessels and in fatty tissue.

The term hamartoma must be distinguished from the term choristoma. This term is used to describe a dysontogenetic tumor caused by tumor-like proliferation of scattered, foreign tissue (choristia).

1. Grundmann (2018) Dignity of tumors. Kurzlehrbuch Pathologie p. 205 Elsevier Munich.

2. Kim BH et al (2005) Intraocular choristoma. Semin Ophthalmol 20:223-229.

3. Zelger B (2003) Nerve-muscle-cartilage-bone and adipose tissue tumors of the skin. In: Kerl H et al (eds) Histopathology of the skin, p. 816. Springer Verlag, Berlin Heidelberg New York.