Diffuse PRAME Expression Is Highly Specific for Thin Melanomas in the Distinction from Severely Dysplastic Nevi but Does Not Distinguish Metastasizing from Non-Metastasizing Thin Melanomas

Cancers, vol. 13, pp. 3864

Abstract

BACKGROUND: PReferentially expressed Antigen in MElanoma (PRAME) immunohistochemistry is increasingly used as diagnostic adjunct in the evaluation of melanocytic tumors. The expression and prognostic significance of PRAME in melanomas ≤1.0 mm and its diagnostic utility in the distinction from severely dysplastic compound nevi (SDN) have not been studied. METHODS: We investigated and compared the immunohistochemical PRAME expression in 70 matched thin metastasizing and non-metastasizing melanomas and 45 nevi from patients with long-term follow-up (35 SDN and 10 unequivocally benign compound nevi). RESULTS: = 0.81). A superficial atypical melanocytic proliferation of uncertain significance, in which the final diagnostic interpretation favored a SDN was the only nevus with diffuse PRAME expression (1/45). Melanomas and SDN with PRAME immunoreactivity exhibited different staining patterns. Most melanomas (67.6%) showed uniform PRAME expression in the in situ and invasive component, whereas most SDN (81.0%) showed a decreasing gradient with depth. CONCLUSION: Diffuse intraepidermal and dermal PRAME staining is highly specific for melanomas in the distinction from SDN. PRAME expression is not a prognostic biomarker in melanomas ≤1.0 mm.

Authors 9

1. Maximilian Gassenmaier corresponding

   University of Tübingen

   Affiliation as printed

   Department of Dermatology, Eberhard Karls University of Tübingen, 72076 Tübingen, Germany

2. Matthias Hahn

   University of Tübingen

   Affiliation as printed

   Department of Dermatology, Eberhard Karls University of Tübingen, 72076 Tübingen, Germany

3. Gisela Metzler

   University of Tübingen

   Affiliation as printed

   Department of Dermatology, Eberhard Karls University of Tübingen, 72076 Tübingen, Germany

4. Jürgen M. Bauer
   Affiliation as printed

   Dermatologie in Stuttgart, 70173 Stuttgart, Germany

5. Amir Sadegh Yazdi Aachen Department of Dermatology and Allergology

   Universitätsklinikum Aachen · RWTH Aachen University

   Affiliation as printed

   Department of Dermatology and Allergology, University Hospital RWTH Aachen, 52074 Aachen, Germany

6. Ulrike Keim

   University of Tübingen

   Affiliation as printed

   Department of Dermatology, Eberhard Karls University of Tübingen, 72076 Tübingen, Germany

7. Claus Garbe

   University of Tübingen

   Affiliation as printed

   Department of Dermatology, Eberhard Karls University of Tübingen, 72076 Tübingen, Germany

   Dermatologie in Stuttgart, 70173 Stuttgart, Germany

8. Nikolaus Benjamin Wagner

   Kantonsspital St. Gallen

   Affiliation as printed

   Department of Dermatology, Venereology and Allergology, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland

9. Stephan Forchhammer

   University of Tübingen

   Affiliation as printed

   Department of Dermatology, Eberhard Karls University of Tübingen, 72076 Tübingen, Germany