Background and Aims: Differential diagnosis of the group of benign trichoblastomas, trichofolliculomas,trichoadenomas and trichoepitheliomas, and basal cell carcinomas (BCCs) is troublesome for the clinician aswell as the pathologist, especially when only small biopsy specimens are available. Here we investigated whetherCD34 expression might be of assistance.
Methods: Thirty benign tumors of cutaneous appendages originatingfrom hair follicles (BTCOHF) and 30 BCCs were retrieved from our archives and immunohistochemicallystained. CD 34 expression was graded from  to [2+] and compared among the groups and subgroups.
Results:There was no significant difference between the degree of expression between  and [1+] and  and [2+] foreach group. However, [1+] and [2+] immunopositivity of BTCOHFs was significantly stronger than in BCCs(p= 0.014).
Conclusions: CD34 may contribute to differential diagnosis of skin lesions.