Hemangioma with dabskoid features: a rare histopathologic variant of acquired hemangioma

Dabska tumor, also known as papillary intralymphatic angioendothelioma (PILA), is a locally aggressive hemangiendothelioma characterized by intravascular papillary proliferations of atypical endothelial cells. Besides PILA, papillary tufts lined by hobnail endothelial cells have been rarely described in vascular proliferations. We report two cases of acquired hemangiomas, which focally showed this finding. We present a 15-year-old male and a 7-year-old girl with erythematous nodules. Both lesions were composed of capillary lobules intermingled with large sinusoidal spaces lined with a single layer of flat endothelial cells, which focally developed intravascular papillary proliferations lined by plump hyperchromatic endothelial cells and a central connective tissue core. Both types of cells were positive with CD31 and ERG and negative for Lyve-1, Prox-1 and podoplanin. Wilm's tumor 1 marker was strongly positive in the capillary hemangioma areas while negative in the intravascular tufts. Both lesions recurred after the first excision but we did not observe further recurrence or evidence of metastasis in the follow-up. In summary, our cases expand the histopathologic findings that may be seen in conventional acquired capillary hemangiomas. The focal presence of dabskoid tufts within an otherwise conventional capillary hemangioma should be not misinterpreted as evidence of malignancy.