Clinical and histopathologic analysis of 46 cases of cutaneous adverse reactions to imatinib.

BACKGROUND

Although many cases of cutaneous adverse reactions to imatinib have been reported, their clinical and histopathologic characteristics are not well documented.

OBJECTIVES

The present study investigated clinical and histopathologic characteristics of cutaneous adverse reactions to imatinib.

METHODS

This retrospective study referred to 46 patients who experienced cutaneous adverse reactions to imatinib. Clinical data including age, sex, skin lesion morphology, underlying disorders, and imatinib treatment parameters (duration of imatinib medication, initial dose, and treatment modifications at the time of the study) were collected. Histopathologic data were available for all patients.

RESULTS

Cutaneous adverse reactions to imatinib developed at 1-24 weeks (median onset: 8 weeks) after imatinib administration. The severity of the reaction was categorized as grade 1 in 22%, grade 2 in 41%, and grade 3 in 37% of patients. Onset was earlier in high-severity reactions than in low-severity reactions. The severity of the reaction was dependent on imatinib dose. Grade 3 reactions were noted in nine of 16 (56%) patients administered "high-dose" (600 mg/d) imatinib. Spongiosis (78% of patients) and papillary dermal edema (83% of patients) were common histopathologic findings in the epidermis and dermis, respectively. Lymphohistiocytes were more predominant than eosinophils in dermal inflammatory infiltration. Histopathologic findings did not differ according to dose of imatinib or severity of the reaction.

CONCLUSIONS

Although the clinical features of cutaneous adverse reactions to imatinib depend on imatinib dose and the severity of the reaction, histopathologic findings are not associated with these clinical variables.