Positive staining of tumor-stage Kaposi sarcoma with lymphatic marker D2-40.

BACKGROUND

Kaposi sarcoma (KS) is a vascular tumor first described by Moritz Kaposi (Kohn) in 1872 and recently linked to human herpesvirus 8. All forms of KS share the same pathologic features, including atypical spindle cells and slitlike vascular spaces. The exact origin of the neoplastic endothelial cells (vascular vs lymphatic) has recently been debated.

OBJECTIVE

We sought to further investigate the origin of neoplastic cells in KS.

METHODS

D2-40, a novel monoclonal antibody to a sialoglycoprotein that reacts with a fixation-resistant epitope in lymphatic endothelium, was used to investigate possible lymphatic origin of neoplastic cells in KS.

RESULTS

We report 5 cases of tumor-stage KS that showed positive staining with lymphatic marker D2-40.

LIMITATIONS

Small study size is a limitation.

CONCLUSION

The origin of neoplastic cells in KS may be lymphatic or mixed lymphatic and vascular. Further studies are needed to elucidate the exact origin of neoplastic cells in KS.