DNA image cytometry in malignant and benign sweat gland tumours

The histopathological differentiation between well-differentiated carcinoma s and atypical adenomas of sweat gland origin may be difficult, even if imm unohistochemical methods are used. Therefore, additional techniques may be helpful. We previously demonstrated that UNA Image cytometry (ICM-DNA) can be useful in distinguishing between malignant and benign clear cell hidrade noma. In the present study, a larger series of sweat gland tumours, with a clear-cut diagnosis as malignant or benign on histopathological criteria, w as examined by ICM-DNA. Enzymatic cell separation specimens were prepared f rom paraffin-embedded tissues of 18 sweat gland carcinomas (14 porocarcinom as, one classic eccrine adenocarcinoma. two microcystic adnexal carcinomas and one mostly ductal apocrine carcinoma) and 47 benign sweat gland tumours (three syringocystadenomas, five spiradenomas. 14 cylindromas, three syrin gomas. seven nodular hidradenomas, 10 cutaneous mixed tumours, four poromas and one apocrine hidrocystoma). Specimens were examined by ICM-DNA accordi ng to the current recommendations of the European Society for Analytical Ce llular Pathology with the AutoCyte QUIC-DNA workstation using mesenchymal c ells as an internal reference. DNA aneuploidy was detected bq the stemline interpretation according to Bocking and/or at least three 5[c]-exceeding ev ents. DNA aneuploidy was detected in 16 of 18 (89%) of the sweat gland carc inomas, but in none of the 47 adenomas, These results suggest that the dete ction of DNA aneuploidy in sweat gland tumours using ICM-DNA is a clear and specific indicator of prospective malignancy.