TUMOURS AND HIV Flashcards
What are the three AIDS defining cancers?
Kaposi sarcoma
High grade B-cell non-Hodgkin’s lymphoma
Invasive cervical cancer
How much more common are high grade B-cell non-Hodgkin’s lymphomas (NHL) in patients who are HIV positive versus the HIV negative population?
60 - 100 times more common
What are the main types of high-grade B-cell non-Hodgkin’s lymphomas (NHL) found in patients who are HIV positive?
2/3rds are diffuse large cell lymphomas
1/3rd are Burkitt or Burkitt like lymphomas
What are the clinical features of systemic (as opposed to cerebral) non-Hodgkin’s lymphoma (NHL)?
Lymph nodal disease (50%)
GI disease (30%)
Extra-nodal disease (20%)
Effusions without nodal masses - primary effusion lymphoma (1%)
What is primary effusion lymphoma (effusions without nodal masses) associated with?
Kaposi sarcoma herpes virus
How do we treat AIDS-related systemic non-Hodgkin’s lymphomas?
Combination anthracycline-based chemotherapy with intrathecal chemotherapy for those at risk of meningeal relapse.
Given with continuing cART (combined anti-retroviral therapy)
What percentage of patients with AIDS-related systemic non-Hodgkin’s lymphomas will achieve durable complete remission?
50-60%
What is primary cerebral lymphoma?
Non-Hodgkin’s lymphoma that is confined to the craniospinal axis without systemic involvement.
Why has the incidence of primary cerebral lymphoma decreased dramatically?
Rates of PCL have been affected by the introduction of cART more than rates of systemic NHL
What are the two most common causes of cerebral mass lesions in people with HIV?
Primary cerebral lymphoma
Toxoplasmosis
What are the clinical features of primary cerebral lymphoma?
Headaches
Focal neurological deficits
Very low CD4 count (less than 50 cells/microlitre)
How might the history help you differentiate primary cerebral lymphoma from toxoplasmosis?
Gradual onset over 2-8 weeks
Absence of fever
What investigations would you do in someone you suspected primary cerebral lymphoma?
CT or MRI
What do CT or MRI show in a patient with primary cerebral lymphoma?
Solitary or multiple ring enhancing lesions with prominent mass effect and oedema.
NB, these features also occur in toxoplasmosis
How might MRI or CT help you differentiate primary cerebral lymphoma from toxoplasmosis?
Look very similar
PCL lesions usually periventricular
Toxoplasmosis more often affects the basal ganglia
How do you initially treat someone who is HIV positive and severely immunodeficient, and is diagnosed with a cerebral lesion?
Assume toxoplasmosis until they do not respond clinically and radiologically for 2 weeks of anti-toxoplasma therapy.
What should you look for in the CSF of all patients in whom you suspect primary cerebral lymphoma?
EBV DNA
What is the investigation that can help differentiate between primary cerebral lymphoma and cerebral toxoplasmosis?
18-Flurodeoxyglucose positron emission tomography (FDG-PET)