Mycosis fungoides-like reaction in a patient treated with Gleevec

Background: Gleevec(TM) is a protein tyrosine kinase inhibitor used in the treatment of chronic myelogenous leukemia and gastrointestinal stromal tumor. Currently, Gleevec is also being used in protocols for treatment of other malignancies such as melanoma. A few, non-descript cutaneous eruptions have been reported in patients receiving Gleevec. Case report: A patient with a gastrointestinal stromal tumor developed a centripetal, slightly pruritic, predominantly macular eruption. Histologically, there was a superficial and mid-perivascular cellular infiltrate of hyperchromatic, large lymphocytes with focal epidermotropism, thus resembling mycosis fungoides. The infiltrate was composed predominantly of T cells (CD3), with a 1:1 CD4:CD8 ratio, therefore consistent with a reactive process, i.e. a drug reaction induced by Gleevec. Conclusion: Gleevec should be considered in the differential diagnosis of pseudolymphoma drug eruptions.