The histopathological differentiation between well-differentiated
carcinomas and atypical
adenomas of sweat gland origin may be difficult, even if immunohistochemical methods are used. Therefore, additional techniques may be helpful. We previously demonstrated that
DNA image cytometry (ICM-
DNA) can be useful in distinguishing between malignant and benign clear cell
hidradenoma. In the present study, a larger series of sweat gland tumours, with a clear-cut diagnosis as malignant or benign on histopathological criteria, was examined by ICM-
DNA. Enzymatic cell separation specimens were prepared from
paraffin-embedded tissues of 18 sweat gland
carcinomas (14 porocarcinomas, 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
syringomas, seven nodular
hidradenomas, 10 cutaneous mixed tumours, four
poromas and one apocrine
hidrocystoma). Specimens were examined by ICM-
DNA according to the current recommendations of the European Society for Analytical Cellular Pathology with the AutoCyte QUIC-
DNA workstation using mesenchymal cells as an internal reference.
DNA aneuploidy was detected by the stemline interpretation according to Böcking and/or at least three 5[c]-exceeding events.
DNA aneuploidy was detected in 16 of 18 (89%) of the sweat gland
carcinomas, but in none of the 47
adenomas. These results suggest that the detection of
DNA aneuploidy in sweat gland tumours using ICM-
DNA is a clear and specific
indicator of prospective
malignancy.