MCQ5

Which tumour is not seen in AIDS?
a. Kaposi sarcoma
b. GI adenocarcinoma
c. Non Hodgkins lymphoma
d. Astrocytoma

Answer and explanation
Answer : "d"

In HIV, the breakdown of the hosts immune response allows easy viral infection.Viral infections are the cause of around 20% of malignancies world wide.

HIV infection is characterised by various malignancies, three of which the CDC has referred to as " HIV defining malagnancies"- they are Kaposis Sarcoma(HHV8), Invasive Cervical Cancer(HPV) and NHL(EBV). These three are reported in unusally high numbers , and are of agressive nature in patients with HIV-AIDS.

Kaposis Sarcoma is caused by Human Herpes Virus 8 infection. 

The same is the case with NHL- the Ebstein Barr virus lodges intself within the B-cells and leads to their proliferation.

Apart from the decreased cell immunity and infection-which prevent a check on malignancies, the HIV itself is thought to produce certain proteins that act as growth factors for the malignant cells.

Although over-represented, the number of HIV related adenocarcinomas ( gastric, pancreatic, colonic) is also on the rise, probably due to the immunodeficient state and co-infection with viruses.

On the other hand, astrocytoma ( an extra cerebral CNS tumor) has no known association with HIV infection. Its causal factor is yet to be known.