Kaposi sarcoma

From Ganfyd

Kaposi sarcoma (KS) is a vascular proliferation of lymphatic endothelial origin and associated with human herpesvirus 8 (HHV-8, Kaposi’s sarcoma-associated herpesvirus). It is commonly seen on the skin, but can affect several other organs.

Previously, it was seen mainly in elderly males of Jewish and Mediterranean extraction (classic endemic KS), but since the advent of HIV, it is is now an AIDS-defining disease (sometimes referred to as AIDS-related KS). Less commonly, it is seen in other forms of immunosuppression. There is debate on whether it is a neoplastic or reactive process.

Histology

Low power photomicrograph showing the slit-like spaces in the dermis.

Higher power view showing the atypical, endothelial-lined, vascular spaces.

Immunohistochemical staining shows a dot-like nuclear staining.

Three stages: early patch stage, plaque stage and nodular stage.

It is characterised by a proliferation of atypical endothelial cell-lined, slit-like vascular spaces, often with a lymphocytic infiltrate. Immunohistochemistry against the HHV8 latent nuclear antigen-1 may help to confirm the diagnosis.

Treatment

• Imatinib
• Interferon
  • Interferon alfa now used infrequently alone
  • In combination with zidovudine or didanosine in HIV patients
• Paclitaxel
• Rapamycin
• Thalidomide