Cytologically interesting cases of primary skin tumors and tumor-like conditions identified by fine-needle aspiration biopsy.

The aims of this study are to depict the special but constant cytomorphologic features which allow a distinction among grossly similar skin tumors and to show that cytological assessment of many uncommon skin lesions is possible. The fine-needle aspiration findings of 181 cytologically interesting cases of primary skin tumors selected from 2,301 primary skin lesions examined in our department from 1990-1995 are described. Seventy-five cases were cytologically reported as benign and 89 as malignant. In 17 cases the aspirated material was considered inconclusive, although some possible diagnoses could be supported. A subsequent histological examination followed the cytologic assessment in all cases. Fine-needle aspiration cytology identified uncommon cutaneous cystic lesions (bronchogenic, dermoid, myxoid), benign and malignant tumors of epidermal appendages such as chondroid syringomas, cylindromas, pilomatrixomas, sebacecous carcinoma, and primary adenoid cystic carcinoma, as well as tumors of the dermis and subcutaneous fat. Primary cutaneous lymphomas were also diagnosed and classified morphologically and immunocytochemically. In our diagnoses of uncommon skin tumors new cytologic criteria were created and utilized and are described in this report in detail.