Oral and Cutaneous Lichenoid Reaction Secondary to Standard Dose Imatinib : A Case Report and Literature

Imatinib mesylate Gleevec®, STI571is an oral cancer drug that selectively inhibits several protein tyrosine kinases associated with human malignancy. The drug is used for the treatment of chronic myeloid leukemia, malignant gastrointestinal stromal tumors, and some other conditions. Treatment with imatinib is generally well tolerated but is not without the risk of adverse effects. Various types of skin eruptions have been reported. Cutaneous side effects with this treatment are common but a lichenoid drug eruption is rare. In this article, we report a 46-year-old woman who presented with lichen planus like lesions on the trunk and extremities, and oral mucosa due to the use of imatinib mesylate for the chronic myeloid leukemia. The literature on lichenoid drug eruption due to imatinib mesylate is reviewed.


INTRODUCTION
Chronic myelogeneous leukemia (CML) is a clonal myeloproliferative disorder which is the first human malignancy to be associated with a specific genetic lesion, the Philadelphia chromosome, carrying BCR-ABL oncogene.Imatinib (Gleevec) is the first molecularly targeted drug developed for CML and has achieved a remarkable success (1)(2)(3).Few side effects are reported with imatinib consisting of mainly hematologic side effects such as neutropenia and thrombocytopenia.Cutaneous side effects with this treatment are common but a lichenoid drug eruption is rare (4).

CASE REPORT
A 46 year-old female with an approximately 15-month history of CML presented with grey-violaceous plaques with a reticular pattern on both cheek mucosal surfaces (Figure 1), and a disseminated purple, prurigenous papules on the trunk, legs, and arms (Figure 2).Dermatological findings were suggestive of lichen planus.She had splenomegaly other than the cutaneous eruption.She had been treated with Gleevec® (Novartis, USA) 400 mg daily for 3 months before onset of the rash.She stated that the eruption spread in the last three weeks.
The punch biopsy taken from the trunk and oral mucosa revealed a lichenoid band of lymphocytes and histiocytes, hypergranulosis, and vacuolar degeneration in the basal layer (Figure 3).The histopathological findings were consistent with lichenoid eruption.The patient was given triamcinolone 0.1% cream topically and oral antihistaminic, which produced improvements in the lesions.
Cutaneous reactions to imatinib appear to be dose-related, appearing more frequently and severely in patients on doses of 600 mg daily or greater.However lichenoid eruption may occur under the standard dose of Imatinib (400 mg/day) (1,7).

CONCLUSION
The early recognition and treatment of cutaneous adverse effects may allow for the continued administration of imanitib.With an increasing number of patients being treated with imatinib, clinicians should be aware of its side effect, even in the standard dose of the drug, and we anticipate further reports of lichenoid and other cutaneous reactions associated with its use.

Figure 1 .
Figure 1.Grey-violaceous plaques with a reticular pattern on both cheek mucosal surfaces.

Figure 3 .
Figure 3. Lichenoid band of lymphocytes and histiocytes, hypergranulosis, and vacuolar degeneration in the basal layer.

Table 1 .
Reported cases of lichenoid drug eruption due to imatinib mesylate