Imatinib-induced Extensive Hyperpigmentation in a Case of Chronic Myeloid Leukemia

Disorders of hyperpigmentation. Part I. Pathogenesis and clinical features of common pigmentary disorders

Disorders of hyperpigmentation are common and, depending on the extent and location of involvement, can affect the quality of life and pose a significant psychologic burden for patients. Given the similarities in presentation of the various causes of hyperpigmentation, it is often difficult to elucidate the etiology of these conditions, which is important to guide management. Furthermore, certain disorders, such as lichen planus pigmentosus and ashy dermatosis, have similar clinical and/or histologic presentations, and their classification as distinct entities has been debated upon, leading to additional confusion. In this review, the authors selected commonly encountered disorders of hyperpigmentation of the skin, subdivided into epidermal, dermal, or mixed epidermal-dermal disorders based on the location of pigment deposition, along with disorders of hyperpigmentation of the mucosa and nails. Melanocytic nevi, genetic disorders, and systemic causes of hyperpigmentation were largely excluded and considered to be outside the scope of this review. We discussed the pathogenesis of hyperpigmentation as well as the clinical and histologic features of these conditions, along with challenges encountered in their diagnosis and classification. The second article in this 2-part continuing medical education series focuses on the medical and procedural treatments of hyperpigmentation.

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.

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.

An Update on Drug-Induced Pigmentation

Drug-induced pigmentation accounts for up to 20% of all cases of acquired pigmentation. A thorough review of medical history and previous and ongoing medications as well as a complete skin examination can guide diagnosis. Implicated agents include alkylating/cytotoxic agents, analgesics, antiarrhythmics, anticoagulants, antiepileptics, antimalarials, antimicrobials, antiretrovirals, metals, prostaglandin analogs, and psychotropic agents, among others. Confirming true drug associations can be challenging, especially in the setting of delayed onset of pigmentation and coexisting polypharmacy.

Imatinib-induced diffuse hyperpigmentation of the oral mucosa, the skin, and the nails in a patient affected by chronic myeloid leukemia: report of a case and review of the literature

BACKGROUND

Imatinib mesylate is a tyrosine-kinase inhibitor used as the first-line treatment in chronic myeloid leukemia patients, but it is also indicated for other hematological diseases and solid tumors. Imatinib treatment is often associated with hypopigmentation, but only a few cases of hyperpigmentation are described in literature.

METHODS

We are reporting the first case of imatinib-related hyperpigmentation involving the oral mucosa, skin, and nails in a patient affected by chronic myeloid leukemia and treated with imatinib since 2002. A review of all the available literature regarding the imatinib-related hyperpigmentation was performed, and one additional case was analyzed. Due to the possibility of a post-inflammatory hyperpigmentation, all cases of pigmentary changes previously characterized by a rash and/or pruritus in the same body areas were excluded.

RESULTS

Thirty cases of well-documented imatinib-related hyperpigmentation were described in literature. In our case, imatinib therapy was well tolerated for several years, and it led to an excellent hematological and cytogenetic response. However, the patient gradually developed a blue-gray pigmentation that involved the nose, fingernails, toenails, pretibial regions, posterior axillary folds, and hard palate. Other causes of pigmentary changes were excluded, and histopathological examination confirmed the clinical suspicion of imatinib-related hyperpigmentation.

CONCLUSIONS

Hyperpigmentation induced by imatinib is an adverse reaction rarely described in literature. The underlying pathogenetic mechanisms are not yet completely clear, and further studies are necessary to elucidate them. Currently, no treatment is required for this condition, and there is no indication to discontinue imatinib treatment.