Radotinib-induced lentiginosis: a report of an adverse cutaneous reaction associated with a tyrosine kinase inhibitor

• Published in: Clinical and experimental dermatology Vol. 41; no. 2; pp. 162 - 165
• Main Authors: Won, K. H., Jo, S. Y., Lee, Y. J., Chang, S. E.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-03-2016; Oxford University Press
• Subjects: Aged; Arm; Benzamides - adverse effects; Facial Dermatoses - chemically induced; Humans; Lentigo - chemically induced; Male; Protein Kinase Inhibitors - adverse effects; Pyrazines - adverse effects
• ISSN: 0307-6938; 1365-2230
• DOI: 10.1111/ced.12706

Summary
Tyrosine kinase inhibitors (TKIs) are associated with various adverse cutaneous reactions, including pigmentary changes. Radotinib is a novel and selective BCR‐ABL1 TKI, which has shown activity and safety in the treatment of patients with chronic myeloid leukaemia resistant or intolerant to imatinib. A 69‐year‐old Korean man presented with lentiginosis after taking radotinib for 6 months. On histopathological examination, the numbers of melanocytes and melanin pigment were found to be increased due to c‐KIT activation, consequently upregulating microphthalmia‐associated transcription factor. This finding is in contrast to previous reports analysing the mechanisms of previously reported tyrosine kinase inhibitors inhibiting c‐KIT.