Related Experiment Video
Updated: Jun 10, 2026

Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Generalized solar lentigines in a patient with a history of radon exposure
Andreas Mauerer1, Regina C Betz, Sandra M Pasternack
1Department of Dermatology, University of Regensburg, Regensburg, Germany.
Abstract:
A woman with generalized lentigines without associated non-cutaneous abnormalities is described. The patient showed brownish-pigmented flat or slightly elevated spots with a diameter of 1–5 mm. The histopathology of the lesions was compatible with a diagnosis of solar lentigines (SLs) or flat seborrhoeic keratosis. Unlike SLs, which develop typically on sun-damaged skin of the face, the dorsum of the hands and forearms, this patient showed the lentigines most prominently on the thighs and lower legs. Besides increased recreational UV exposure, the patient had a history of occupational radon exposure in a spa with radon-containing water. Genetic analysis identified a p.S249C FGFR3 hotspot mutation in 1 lesion, supporting the diagnosis of SLs. It remains elusive whether the occupational exposure to radon-containing water in addition to the recreational UV light exposure caused the unusual distribution of the SLs in this patient.
Related Concept Videos
Skin Cancer
Basal Cell Carcinoma (BCC): BCC is the most common type of skin cancer, accounting for about 80% of cases. It typically develops in...
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Biological Effects of Radiation
Non-LTR Retrotransposons
