Lisch nodule pathophysiology: Difference between revisions
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*A hamartoma is defined as a benign tumor or nodular growth that is composed of proliferating mature histologically normal cells that normally reside at the affected tissue | *A hamartoma is defined as a benign tumor or nodular growth that is composed of proliferating mature histologically normal cells that normally reside at the affected tissue | ||
**In ophthalmic jargon, iris hamartomas traditionally refer to Lisch nodules which are encountered in patients with neurofibromatosis type 1 (NF1). | **In ophthalmic jargon, iris hamartomas traditionally refer to Lisch nodules which are encountered in patients with neurofibromatosis type 1 (NF1). | ||
*NF1 is due to mutations in the NF1 gene, located at chromosome 17q11.2 | |||
*Neurofibromin, the protein product encoded by the gene, is expressed in many tissues, including brain, kidney, spleen, and thymus | |||
*Mutations in the NF1 gene result in loss of production or reduced function of protein; this causes a wide spectrum of clinical findings, including NF1-associated tumors | |||
*Histopathologically, Lisch nodules are composed of melanocytes and spindle cells, usually concentrated on the superficial layers of the iris stroma. <ref name="Kiratli2011">{{cite journal|last1=Kiratli|first1=H|title=Head and Neck: Iris Hamartomas|journal=Atlas of Genetics and Cytogenetics in Oncology and Haematology|issue=1|year=2011|issn=1768-3262|doi=10.4267/2042/44673}}</ref> | *Histopathologically, Lisch nodules are composed of melanocytes and spindle cells, usually concentrated on the superficial layers of the iris stroma. <ref name="Kiratli2011">{{cite journal|last1=Kiratli|first1=H|title=Head and Neck: Iris Hamartomas|journal=Atlas of Genetics and Cytogenetics in Oncology and Haematology|issue=1|year=2011|issn=1768-3262|doi=10.4267/2042/44673}}</ref> | ||
*The spindle cells are larger than the normal iris melanocytes. | *The spindle cells are larger than the normal iris melanocytes. | ||
Latest revision as of 14:26, 12 June 2019
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Swathi Venkatesan, M.B.B.S.[2]
Pathophysiology of Lisch Nodule
- A hamartoma is defined as a benign tumor or nodular growth that is composed of proliferating mature histologically normal cells that normally reside at the affected tissue
- In ophthalmic jargon, iris hamartomas traditionally refer to Lisch nodules which are encountered in patients with neurofibromatosis type 1 (NF1).
- NF1 is due to mutations in the NF1 gene, located at chromosome 17q11.2
- Neurofibromin, the protein product encoded by the gene, is expressed in many tissues, including brain, kidney, spleen, and thymus
- Mutations in the NF1 gene result in loss of production or reduced function of protein; this causes a wide spectrum of clinical findings, including NF1-associated tumors
- Histopathologically, Lisch nodules are composed of melanocytes and spindle cells, usually concentrated on the superficial layers of the iris stroma. [1]
- The spindle cells are larger than the normal iris melanocytes.
- Immunohistochemical studies show positive reaction against vimentin, smooth muscle actin and neuron specific enolase.
References
- ↑ Kiratli, H (2011). "Head and Neck: Iris Hamartomas". Atlas of Genetics and Cytogenetics in Oncology and Haematology (1). doi:10.4267/2042/44673. ISSN 1768-3262.