The question asks for identifying what is not related to HIV among the given options. Let's examine each option briefly:
- Primary CNS lymphoma: This is a type of brain tumor and is associated with HIV, especially in patients who are immunocompromised.
- Tertiary syphilis: This refers to the late-stage symptom of syphilis, a separate sexually transmitted infection, which isn't directly related to HIV, although both can be co-infections in the same individual.
- Oesophageal candidiasis: This is a fungal infection in the esophagus and is commonly associated with HIV due to the weakened immune system.
- None: This implies that all options are related to HIV, which is incorrect given that tertiary syphilis is a distinct condition.
Based on this analysis, tertiary syphilis is the condition that is not directly related to HIV.