Follicular mucinosis and mycosis-fungoides-like drug eruption due to leuprolide acetate: a case report and review.

Leuprolide acetate represents a gonadotropin-releasing hormone agonist, used as part of the treatment of prostate cancer. We report an unusual case of disseminated urticarial rash following leuprolide injection in a 67-year-old man that histopathologically and immunohistochemically resembled mycosis-fungoides, including the presence of follicular mucinosis and eosinophils in the follicles. This histopathologic pattern has not been previously described as a drug reaction pattern due to leuprolide, and it underscores the importance of correlation with the clinical impression to arrive at a correct diagnosis.