Diagnosis

The best way to diagnose KS is by biopsy - taking a 4 to 6mm sample of a skin lesion and examining it under the microscope. However, some doctors experienced in treating HIV may be able to diagnose KS without performing a biopsy.

Lesions in the lung can be inspected using a flexible fibre-optic instrument called a bronchoscope, but biopsy samples are generally not taken because of the risk of causing internal bleeding or a collapsed lung. Chest X-rays and scans can also reveal the presence of lung tumours. KS in the intestines can be viewed with a fibre-optic endoscope, but biopsy samples often test negative because the lesions themselves are under the surface, rather than on it.

Antibody and polymerase chain reaction (PCR) viral load tests for HHV-8 have been developed but are not widely available. However, not everyone who has been infected with HHV-8 has detectable HHV-8 in the blood. Currently, the two tests are considered equally effective at determining a person's risk of developing KS.

Preliminary research has found that people with KS lesions had higher levels of HHV-8 and that high or rising levels were associated with the progression of KS. HHV-8 levels fall when KS is treated with chemotherapy. In the future, it is possible that blood levels of spindle cells, growth factors and certain hormones may be measured to help in the diagnosis of KS.