An HIV patient developed goitre. On examination there was non-tender diffuse enlargement of thyroid. All of the following can be cause of it, except:
**Core Concept**
The question is testing the association between HIV infection and thyroid abnormalities. In HIV patients, immune system dysregulation and chronic inflammation can lead to various endocrine disorders, including thyroid dysfunction.
**Why the Correct Answer is Right**
The most common cause of goitre in HIV patients is secondary to opportunistic infections, such as tuberculosis (TB) affecting the thyroid gland. TB is a well-known complication of HIV infection, and when it involves the thyroid, it can cause a non-tender diffuse goitre. This is due to the inflammatory response and fibrosis resulting from the infection.
**Why Each Wrong Option is Incorrect**
**Option A:** **Autoimmune thyroiditis** is a possible cause of thyroid dysfunction in HIV patients, as they are more susceptible to autoimmune disorders. However, it typically presents with a more localized and tender goitre.
**Option B:** **Iodine deficiency** is a common cause of goitre worldwide, but it is less relevant in HIV patients, who often have access to iodized salt and may have other underlying nutritional deficiencies.
**Option C:** **Thyroid lymphoma** is a rare but serious complication of HIV infection, often presenting with a rapidly enlarging, painless thyroid mass. This option is a possible cause of goitre in HIV patients.
**Clinical Pearl / High-Yield Fact**
In HIV patients, it is essential to investigate thyroid abnormalities thoroughly, as they may be a sign of an underlying opportunistic infection or malignancy.
**Correct Answer:** A. Autoimmune thyroiditis