On the contrary, positive expression of a-SMA was found in the epidermis basal layer in 100% of HS and KS (38/38 and 55/55 cases, respectively), in appendages (36/38 of HS and 52/55 of KS) and blood vessels (37/38 of HS and 54/55 cases of KS). Here, SMN1 is linked to histiocytic sarcoma.