Cell cycle–associated proteins in melanotic neuroectodermal tumor of infancy

Objective. The purpose of the present study was to compare the immunohistochemical expression of cell cycle–associated proteins in neuroblastic and melanocytic cell populations of melanotic neuroectodermal tumor of infancy. Study design. Three cases of melanotic neuroectodermal tumor of infancy were selected. The immunohistochemical expression of MDM-2, p53, proliferating cell nuclear antigen, cyclin D1, and cyclin A was assessed through use of the streptavidin-biotin-peroxidase complex technique. Results. Positive immunostaining for MDM-2, proliferating cell nuclear antigen, cyclin D1, and cyclin A was occasionally observed in the large melanin-containing epithelioid cells. Conclusions. These data suggest that MDM-2 expression may be important for the development of melanotic neuroectodermal tumor of infancy and that the melanocytic cell population, not the neuroblastic one, is the proliferative component of the tumor. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999;88:466-8)