p16 Expression: A marker of differentiation between childhood malignant melanomas and Spitz nevi - 28/07/11
, Mehdi Agoumi, MD b, Isabelle Gagné, MD b, Catherine McCuaig, MD, FRCPC a, Julie Powell, MD, FRCPC a, Victor Kokta, MD, FRCPC b
Correspondence to: Rola Al Dhaybi, MD, Department of Pathology, Centre Hospitalier Universitaire Sainte-Justine, 3175 Chemin Côte-Sainte-Catherine, Montreal H3T 1C5 Quebec, Canada.Abstract |
Background |
Childhood malignant melanomas frequently present as nodular melanomas with Spitzoid features. Spitz nevus and Spitzoid melanoma overlap clinically and histopathologically and there have been many attempts to differentiate between them. Spitz nevi differ from melanomas by their immunohistochemical pattern of expression of cell cycle and apoptosis regulators such as the p16 protein.
Objective |
The aim of this study was to evaluate in a childhood population the expression of p16 in nodular malignant melanoma of Spitzoid type, Spitz nevi, and a control group of benign compound melanocytic nevi.
Methods |
We performed immunohistochemical studies for expression of p16 in 6 Spitzoid malignant melanomas, 18 Spitz nevi, and 12 compound melanocytic nevi in children younger than 18 years. Statistical analysis was used to compare p16 expression, mitotic count/mm2, and Ki-67 index of childhood nodular malignant melanomas and Spitz nevi.
Results |
All the childhood melanoma cases were associated with loss of p16 without any correlation with their Breslow thickness whereas all the Spitz nevi and benign melanocytic nevi had strong positive nuclear and cytoplasmic expression of p16 staining. We found a statistically significant difference in p16 expression, mitotic counts, and Ki-67 index when comparing the Spitzoid melanomas with the Spitz nevi.
Limitations |
This study is limited by the small number of malignant melanomas, which are known to be rare in childhood.
Conclusion |
p16 Expression in childhood nodular Spitzoid malignant melanomas and Spitz nevi, in conjunction with clinical and histopathological evaluation, may be a useful tool in differentiating between these two entities.
Le texte complet de cet article est disponible en PDF.Key words : benign melanocytic nevus, childhood, nodular melanoma, p16, Spitz nevus, Spitzoid malignant melanoma, tumor suppressor gene
Plan
| Funding sources: None. |
|
| Conflicts of interest: None declared. |
|
| Reprints not available from the authors. |
Vol 65 - N° 2
P. 357-363 - août 2011 Retour au numéro
Article précédent
- Nonablative fractional photothermolysis for facial actinic keratoses: 6-month follow-up with histologic evaluation
- Tracy M. Katz, Leonard H. Goldberg, Denise Marquez, Arash Kimyai-Asadi, Kristel D. Polder, Jennifer M. Landau, Paul M. Friedman
- Clinicohistopathological correlations in juvenile localized scleroderma: Studies on a subset of children with hypopigmented juvenile localized scleroderma due to loss of epidermal melanocytes
- Joanne J. Sung, Tina S. Chen, Anita C. Gilliam, Timothy H. McCalmont, Amy E. Gilliam
Bienvenue sur EM-consulte, la référence des professionnels de santé.
L’accès au texte intégral de cet article nécessite un abonnement.
Déjà abonné à cette revue ?