Disappearing pigmentary mosaicism during imatinib treatment for gastrointestinal stromal tumors

Imatinib is a first-generation tyrosine kinase inhibitor of bcr-abl, PDGF receptor, and c-kit, approved for the treatment of chronic myelogenous leukemia and other malignancies such as metastatic or unresectable gastrointestinal stromal tumors (GISTs).1 Several dermatologic adverse events have been associated with its use including maculopapular eruptions, periorbital edema, lichenoid dermatitis, and pigmentary alteration.1 We report a case of disappearing pigmentary mosaicism in the form of segmental speckled lentiginous nevi during imatinib therapy for GISTs.