The blue palate-A case series of imatinib-related oral pigmentation and literature review

Pigmented oral mucosal lesions are diverse, and differential diagnosis can range from benign conditions such as oral melanotic macule to malignancies such as oral malignant melanoma. Imatinib mesylate is a tyrosine kinase inhibitor used as a first-line medication in the management of oncohematological conditions such as chronic myeloid leukemia and gastrointestinal stromal tumors. Side effects of imatinib therapy are common, and paradoxically imatinib has been associated with both hypo- and hyperpigmented lesions, the underlying mechanism for which is still unclear. Hyperpigmentation associated with imatinib therapy is a potentially underreported phenomenon. This article presents an in-depth, clinicopathological review of the literature surrounding imatinib-related hyperpigmentation, alongside a case series of imatinib-related oral pigmentation with notable practical learning points. A pragmatic flowchart to help clinicians in the diagnosis and management of oral pigmented lesions is provided, as well as advice on the application of the ABCDE criteria to standardize recording of oral pigmented lesions.