RESUMO
BACKGROUND: Protooncogene, bcl-2 is known to inhibit, apoptosis induced by various stimuli. Its expression has been reported in various fetal and adult tissues, and also in tumors of neural origin. OBJECTIVE: The purpose of this study was to evaluate the expression of bcl-2 in a skin tumor of neuroectodermal origin and to estimate whether this expression was useful in the different,ial diagnosis of tumors of neural origin or not. METHOD: Immunohistochemical stains by the LSAB(labelled streptavidin biotin) method for bcl-2 protein were performed in normal special nerve end-organs and a skin tumor of neural origin. RESULTS: The immunohistochemical findings revealed strong positive results in Meissners corpuscles, but weak week positive results in Vater-Pacini corpuscles. There were also strong positive results in neurilernmomas which were mostly composed of Schwann cells, but results were mostly negative in neurofibromas and neurofibrosarcomas which were composed primarily of endoneurial fibroblasts of mesodermal origin except a few cells of Schwann cell origin. Benign granular cell tumors arising from Schwann cells, and Merkel cell carcinoma known to arise from the Merkel cells of neural crest origin showed strong positive reactions. CONCLUSION: The strong expression of bcl-2 protein exclusively in the tumor of neuroectodermal origin suggests a useful indicator for the differential diagnosis of skin tumors of neural origin.