Dabska tumor arising in lymphangioma circumscriptum.

We describe a case of Dabska tumor (DT) occurring within a large congenital lymphangioma circumscriptum on the thigh of a 14-year-old female. Diagnostic biopsy showed numerous intravascular papillary projections lined by atypical endothelial cells within the anastomosing vascular channels of a lymphangioma circumscriptum. DT is regarded as a vascular tumor of intermediate malignant potential, most probably of lymphatic origin. Although it has been described in pre-existing lymphangiomas, to the best of our knowledge this is the first case to be described in a pre-existing lymphangioma circumscriptum. During a follow-up of 9 years, the lymphangioma circumscriptum has recurred, but there has been no evidence of DT recurrence or metastasis.