[Symplastic hemangioma].

Background And Objective: Endothelial nuclear atypia is the hallmark of malignant vascular tumors. Pleomorphic nuclei of the muscular vessel wall and the adventitia are manifestations of degenerative phenomena and should not be misinterpreted as signs of malignancy.

Patients/methods: Three long-standing solitary superficial vascular tumors (61-year-old woman, 48- and 63-year-old men) were removed by primary excision. Sections were stained according to standard histologic and immunohistologic protocols.

Results: Symplastic hemangiomas show the silhouette of a small superficial angioleiomyoma or capillary hemangioma. Characteristic features are multinucleate cells of the muscular vessel wall and the adventitia with pleomorphic nuclei, broad hyalinized vessel walls, and the distinctive lack of endothelial nuclear atypia. Recurrences or metastases were not reported (follow-up of 9, 45 and 90 months).

Conclusions: Symplastic hemangioma is a benign superficial hemangioma with histological features of a pseudomalignancy. The distinctive lack of endothelial nuclear atypia allows distinction from malignant vascular tumors.