title: Expression of p16 in sinonasal malignant melanoma.
abstract: The aim of this study was to investigate the expression of p16 in relation with the histopathologic features and the clinical course in patients with sinonasal melanoma. Thirty-seven sinonasal melanomas were immunostained for p16. Seventeen tumours were investigated for loss of the 9p21 region using interphase fluorescence in situ hybridization (FISH). Twenty-seven melanomas (72.9%) showed loss of p16 expression. All cases with spindle or mixed cytology showed loss of p16, whereas this was present in 50% of epithelioid tumours (p=0.01). Loss of p16 expression was more frequently seen in melanomas with alveolar architecture (87.5%) than in tumours with diffuse architecture (68.9%) (p=0.4). There was no correlation between p16 expression and presence of lymph node or distant metastases (p=0.57 and 0.24, respectively). In addition, p16 status did not influence overall survival (p=0.2). The FISH results were in good agreement with immunohistochemistry: 11 tumours out of 17 showed deletion of the 9p21 region and 10 of these showed loss of protein expression. Loss of p16 expression is a frequent event in sinonasal melanoma and it is mainly related to deletion of 9p21 region. At variance from cutaneous melanoma, loss of p16 is not correlated with the prognosis of patients affected by sinonasal melanoma.
authors.affiliation: Department of Human Pathology and Oncology, University of Florence, Viale G.B. Morgagni 85, 50134 Florence, Italy. Franchi@unifi.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Franchi
authors.forename: Llucia
authors.initials: L
authors.lastname: Alos
authors.forename: Nina
authors.initials: N
authors.lastname: Gale
authors.forename: Daniela
authors.initials: D
authors.lastname: Massi
authors.forename: Milena
authors.initials: M
authors.lastname: Paglierani
authors.forename: Marco
authors.initials: M
authors.lastname: Santucci
authors.forename: Nina
authors.initials: N
authors.lastname: Zidar
authors.forename: Antonio
authors.initials: A
authors.lastname: Cardesa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008545:Melanoma / Q000737:chemistry* / Q000473:pathology; D008875:Middle Aged; D010255:Paranasal Sinus Neoplasms / Q000737:chemistry* / Q000473:pathology
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16