Unusual multifocal intraosseous papillary intralymphatic angioendothelioma (Dabska tumor) of facial bones: a case report and review of literature

Papillary intralymphatic angioendothelioma (PILA) or Dabska tumor is extremely rare, and often affects the skin and subcutaneous tissues of children. Since its first description by Dabska, only a few intraosseous cases have been described in the literature and none of them presents with multifocal osteolytic lesion of bones. We present a case of unusual multifocal intraosseous PILA in facial bones occurring in a 1 year 3 month old male child. Computed tomography (CT) scan revealed multifocal osteolytic lesions were located at the left zygoma, left orbital bone and right maxillary. Histologically, the lesions were ill-defined and composed of multiple delicate interconnecting vascular channels with papillae formation which projected into the lumen lined by atypical plumped endothelial cells. The vascular channels were also lined by plump cuboidal endothelial cells with focal hobnailed or "match-head" appearance. In some areas, endothelial cells formed solid-appearing aggregates with vessel lumens. By immunohistochemistry, the tumor cells were positive for CD31, CD34 and D2-40 at varying intensity. A final diagnosis of intraosseous PILA was made. To the best of our knowledge, this case is the first case of primary multifocal osseous PILA.