Lisch nodule
Template:Infobox medical condition (new)
Lisch nodule, also known as iris hamartoma, is a pigmented hamartomatous nodular aggregate of dendritic melanocytes affecting the iris,[1] named after Austrian ophthalmologist Karl Lisch (1907–1999), who first recognized them in 1937.[2]
The first published use of the term Lisch nodule was in the New England Journal of Medicine "Medical Progress" series article of December 31, 1981 (Riccardi VM: Von Recklinghausen Neurofibromatosis. N Engl J Med 1981;305:1617–27).
These nodules are found in neurofibromatosis type 1, and are present in greater than 94% of patients over the age of six.[1] They are clear, yellow-brown,[3] oval to round, dome-shaped papules that project from the surface of the iris. These nodules typically do not affect vision, but are very useful in diagnosis.[1] They are detected by slit lamp examination.[3] Immunohistochemistry stains positive against the proteins vimentin and S-100, and points to an ectodermal origin for the nodules.[2] Their precise origin and structure, however, are still under investigation.[3] They can rarely be seen in neurofibromatosis type 2.[4]