Morphologic and immunophenotypical features distinguishing Merkel cell polyomavirus-positive and negative Merkel cell carcinoma.

Fiche publication


Date publication

juin 2019

Journal

Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc

Auteurs

Membres identifiés du Cancéropôle Est :
Pr AUBIN François


Tous les auteurs :
Kervarrec T, Tallet A, Miquelestorena-Standley E, Houben R, Schrama D, Gambichler T, Berthon P, Le Corre Y, Hainaut-Wierzbicka E, Aubin F, Bens G, Tabareau-Delalande F, Beneton N, Fromont G, Arbion F, Leteurtre E, Herfs M, Touzé A, Samimi M, Guyétant S

Résumé

In 2008, Feng et al. identified Merkel cell polyomavirus integration as the primary oncogenic event in ~80% of Merkel cell carcinoma cases. The remaining virus-negative Merkel cell carcinoma cases associated with a high mutational load are most likely caused by UV radiation. The current study aimed to compare the morphological and immunohistochemical features of 80 virus-positive and 21 virus-negative Merkel cell carcinoma cases. Microscopic evaluation revealed that elongated nuclei-similar to the spindle-shape variant of small cell lung cancer-were less frequent in Merkel cell polyomavirus-positive Merkel cell carcinoma compared to the virus-negative subset (p = 0.005). Moreover, virus-negative cases more frequently displayed a "large-cell neuroendocrine carcinoma" phenotype with larger cell size (p = 0.0026), abundant cytoplasm (p = 4×10) and prominent nucleoli (p = 0.002). Analysis of immunohistochemical data revealed frequent positivity for thyroid transcription factor 1 and cytokeratin 7, either absence or overexpression of p53, as well as frequent lack of neurofilament expression in virus-negative cases. By contrast, cytokeratin 8, 18 and 20 and a CD99 with a dot pattern as well as high EMA expression were identified as characteristic features of virus-positive Merkel cell carcinoma. In particular, the CD99 dot-like expression pattern was strongly associated with presence of the Merkel cell polyomavirus in Merkel cell carcinoma (sensitivity = 81%, specificity = 90%, positive likelihood ratio = 8.08). To conclude, virus-positive and -negative Merkel cell carcinoma are characterized by distinct morphological and immunohistochemical features, which implies a significant difference in tumor biology and behavior. Importantly, we identified the CD99 staining pattern as a marker indicating the virus status of this skin cancer.

Référence

Mod. Pathol.. 2019 Jun 14;: