Dabska Tumor Workup

Updated: Apr 06, 2021
  • Author: Robert A Schwartz, MD, MPH; Chief Editor: Dirk M Elston, MD  more...
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Laboratory Studies

DT tumor cells express immunoreactivity for factor VIII–related antigen, Ulex europaeus agglutinin I, vimentin, blood group isoantigens, and C 2.1 antibody, but not for S-100 protein, cytokeratins, epithelial membrane antigen, Leu-M1, HLA-DR, alpha-1-antichymotrypsin, and leukocyte common antigen. They also may show positive reactivities for CD31, CD34, and alpha-smooth muscle actin in most of the tumor cells and CD68 in some tumor cells.

The factor VIII–related antigen and Ulex europaeus agglutinin I immunoreactivity and other findings, even in the absence of HLA-DR expression, imply these neoplastic cells differentiate toward high endothelial cells, ie, those with surface receptors that serve as ligands in the selective homing of lymphocytes in lymphoid organs.

In one patient, dilated tumor vessels appeared to be filled with lymph rather than blood. Accordingly, the DT appeared to be more like a lymphangioma than a hemangioma. This concept is further embellished by the finding of the lymphatic endothelial cell marker vascular endothelial cell growth factor receptor type 3 in 8 of 8 cases examined. Nevertheless, note that this marker also may be evident in fetal blood vessels prior to lymphatic differentiation.


Histologic Findings

DTs usually have normal overlying epidermis. The dermis has multiple vascular channels that interconnect and are lined by atypical endothelial cells. They may be partially filled with clear fluid. At low power, DTs appear similar to cavernous lymphangiomas. A unique pattern is their papillary structure lined with atypical columnar endothelial cells. Some papillary plugs have a central hyalinized core and project into a lumen lined by atypical columnar endothelial cells. These outpouchings sometimes appear in a glomeruluslike pattern.

Individual endothelial cells range from cuboidal to tall and cylindrical with vacuolated cytoplasm and hyperchromatic eccentric nuclei on their luminal border, thus resembling epithelium. Mitotic figures are uncommon. Many intraluminal lymphocytes may be evident, often attached to the endothelial cells. Focal changes characteristic of retiform hemangioendothelioma may occasionally be observed. Intravascular proliferations may stain positively for actin.

Ultrastructural studies demonstrate tumor cells with irregular nuclei, abundant perinuclear cytoplasmic filaments, and many pinocytotic vesicles. Weibel-Palade bodies may be evident. The hyaline globules consist of electron-dense basement membrane material.

Diagnosis of DT has been rendered by characteristic histopathology using fine-needle aspiration. [32] This technique may produce a smear showing many small clusters of tumor cells with rosettelike arrangement, along with papillary fragments with a fibrovascular core and hobnail-like arrangement of the cells.

See the image below.

Retiform hemangioendothelioma (Dabska tumor). Cour Retiform hemangioendothelioma (Dabska tumor). Courtesy of L Wozniak & KW Zielinski (own work), via Wikimedia Commons.