Hyperpigmentation due to imatinib: A rare case of cutaneous involvement.

CASE REPORT: Imatinib mesylate is a well-known tyrosine kinase inhibitor used to treat chronic myeloid leukemia, gastrointestinal stromal tumor, as well as a variety of other malignancies.Management and outcome: As use of this medication continues to grow, providers must be aware of potential side effects and management thereof. The toxicity profile of imatinib has been well characterized with most patients experiencing a grade 1 or 2 adverse event. These side effects are usually mild, and most patients can continue treatment without interruption. Around 30% of patients on imatinib experience skin toxicity, with 5% being high grade. This rash is typically hypopigmented, which is explained by imatinib's effect on melanocytes.

DISCUSSION: Although there have been several case reports describing hyperpigmentation of the oral mucosa or nails, very few have described skin hyperpigmentation. We previously reported the first two cases of imatinib-related squamous cell carcinoma in patients undergoing treatment for gastrointestinal stromal tumors. In this paper, we present a case of a patient on imatinib for management of gastrointestinal stromal tumor who experienced extensive skin hyperpigmentation and review the literature.