Dabska tumorDabska tumor (papillary intralymphatic angioendothelioma, PILA) is a rare low-grade angiosarcoma. It affects mainly infants and young children and can be congenital. Rare adult cases have been reported. The tumor typically presents as a superficial ill-defined, pink to purple plaque-like lesion of the head, neck and extremities. Deep soft tissue cases have also been described, as well as a case of testicular PILA in a young boy. Dabska tumor can arise in a preexisting hemangioma. The lesion is typically slow growing.
Histologically the tumor consists of anastomosing vascular spaces lined by atypical endothelial cells which range from cuboidal to tall columnar with focal hobnail appearance. The endothelial cells form charachteristic papillary tuft-like projections which can have glomeruloid appearance. Mitoses may be evident. Intraluminal lymphocytes are typically present attached to the endothelium.
Dabska tumors typically stain positive for Von-Willebrand factor (vWF), CD31, D2-40, and focally positive for CD34. Cytokeratins, EMA and S-100 are negative.
Dabska tumor carries a favorable prognosis and rarely metastasizes. It may recur locally and wide excision is therefore recommended.
Dabska tumor was originally described in 1969 by Maria Dabska as malignant endovascular papillary angioendothelioma of the skin in childhood. In the 2002 WHO classification of soft tissue tumors it is referred to as papillary intralymphatic angioendothelioma and assigned to the category of vascular tumors of intermediate malignancy that rarely metastasize. Dabska tumor shows significant overlap with retiform hemangioendothelioma and the two are often regarded as variants of the same entity.