Objective: To study the expression of apoptosis and their regulatory genes, Bcl-2, Bax in hemangioma and vascular malformations.
Methods: The specimens were taken from 68 cases of strawberry hemangioma or vascular malformations and 11 cases of normal skin. The expression of Bcl-2, Bax and Ki-67 in endothelial cells were investigated by immunohistochemical S-P method. The apoptosis index (AI) in endothelial cells was investigated by TUNEL method.
Results: Ki-67 was positive in all the proliferating strawberry hemangioma, negative in the other groups. The expression of Bax was significantly higher in strawberry hemangioma than in vascular malformations and normal skin (P < 0.01). Bcl-2 was negative in all groups. The AI in endothelial cells of strawberry hemangioma was significantly higher than that of vascular malformations and normal skin. There were no statistically significant differences between the proliferating and involution strawberry hemangioma. There were no statistically significant differences between various types of vascular malformations and normal skin. With the increasing of the expression of Bax in strawberry hemangioma, the AI increased.
Conclusion: These findings clearly demonstrate a much higher apoptotic activity in strawberry hemangioma than in vascular malformations and normal skin and suggest that apoptosis might be a cause of spontaneous involution of strawberry hemangioma and might not be a cause of the pathogenesis of vascular malformation. Bcl-2, Bax might play an important regulatory role in apoptosis in endothelial cells of strawberry hemangioma.