Mycosis fungoides with focal CD 30 transformation in an adolescent.

Mycosis fungoides is rare in children and adolescents. Large cell transformation in mycosis fungoides is typically seen in adult patients with advanced disease. We describe a 16-year-old girl with patch/plaque stage mycosis fungoides who developed a nodule within one of the plaques, which on histopathology showed large cell transformation, with positive labeling with the CD30 immunostain.