Multiple scalp nodules Case

A 45-year-old man presented with multiple ulcerated and erythematous nodules on his scalp. the first lesion appeared on his vertex as an erythematous plaque five years ago and there was gradual increase in size and number of the lesions ever since. he was otherwise healthy. physical examination showed multiple erythematous nodules, some were crusted, on the vertex (fig.1). no lymphadenopathy was detected and general examination was unremarkable. the scalp lesion was biopsied and immunohistochemical staining was performed on the specimen.