Inflammatory mixo-hyaline tumor of distal extremities - a rare sarcoma simulating benign diseases*

standard tray including cosmetics) and, at the 96-hour reading, it was positive for thimerosol (1+) and nickel sulfate (1+). Tretinoin was tested at 0.005% and 0.01% in an alcohol solution and 0.05% in vaseline. The test was positive for the 0.05% concentration only, with a reaction intensity of 1+ in both readings: at 48 and at 96 hours. The occurrence of a high intensity and a rapid onset of a dermatitis condition, with the formation of vesicles and blisters after the tretinoin peeling is still a relatively unknown event. No similar case has been reported in prior literature. Standardization of tretinoin patch testings is defective due to the irritating nature of retinoic acid. Different tretinoin concentrations were used in some case reports.4,5 Despite its exuberance, the onset of this condition took place before 24 hours after the peeling application, and tretinoin positivity was only observed at the highest concentration, which maintained the same intensity of 1+ at the 48and 96-hour readings, which suggests irritant contact dermatitis. Patient has been under dermatology follow-up, using topical medications, and submitted to salicylic acid peeling at 30%, without intercurrent events. Despite the intense adverse reaction, patient progressed to full recovery. q