Diagnostic value of Tzanck smear in the diagnosis of non-melanoma skin tumors

Cytology is a diagnostic method which studies characteristic features of cells. It was applied for the first time in dermatologic diseases by Arnault Tzanck in 1947. Tzanck cytology has been used for many erosive-vesiculobullous, nodular and tumoral diseases until now. Cytology has been applied by a few dermatologists as a reliable diagnostic method. It is quick, simple, cheap, not requiring local anaesthesia and performable in outpatient conditions for various skin diseases under the supervision of experienced experts. A great variety of skin diseases such as genodermatoses (Hailey-Hailey and Darier's disease), infections (herpes simplex, molluscum contagiosum, leishmaniasis), immune disorders (pemphigus) and cutaneous tumours (basal cell carcinoma, squamous cell carcinoma, malignant melanoma, mastocytoma) can be diagnosed by the Tzanck smear. The frequency of nonmelanoma skin cancers in the world and our country is progressively increasing. Basal cell carcinoma is the most frequently observed type among non melanoma skin cancers. This tumor can quickly be diagnosed by the Tzanck smear since it has typical cytologic findings. Nevertheless, the sole use of cytology is not enough to discriminate squamous cell carcinoma from tumoral lesions such as keratoacanthoma and actinic keratosis. The aim of this study is to determine the sensitivity and specifity of cytology in diagnosing nonmelanoma skin cancers with respect to histopathology, which is the gold standard method. Fifty-three patients clinically suspected to have nonmelanoma skin cancer were included in the study. Samples were taken from the lesions of the patients by the slit-skin and scraping methods. The material so obtained was spreaded onto slides. It was dried, stained with Giemsa, and then examined. The patients were directed to the plastic surgery clinic in order to obtain excisional and incisional biopsy specimens from the lesions for the histopathologic examination. In the study, 25 patients were female and 28 patients were male. The ratio of male patients to female patients was 1.12. The average age of the patients was 62.3±10.9 years. As a result of the cytologic study, 40 of the 53 lesions were diagnosed as basal cell carcinoma, 7 of the lesions as squamous cell carcinoma, 3 of the lesions as actinic keratoses, 2 of the lesions as Bowen's disease and one of the lesions as keratoacanthoma. Histopathology confirmed that 39 of the patients were basal cell carcinoma, 5 of the patients were squamous cell carcinoma, 5 of the patients were actinic keratosis, 2 of the patients were Bowen's disease, one of the patients was keratoacanthoma and one of the patients was epithelial hyperplasia. As a result of these findings, the sensitivity of cytology was 94.87% and the specificity of cytology was 78.57% for basal cell carcinoma. The sensitivity of cytology was 60% and the specificity of cytology was 91.66% for the squamous cell carcinoma. Key words: Cytology, Tzanck smear, non-melanoma skin cancers