Goitre can occur as a consequences of all the following except

Options

A. Grave's disease
B. Excessive intake of exogeneous thyroxine
C. Iodine deficiency
D. Pituitary adenoma

Answer

To solve the question regarding the causes of goitre, we need to analyze each option provided and determine which one does not lead to the condition of goitre.

### Step-by-Step Solution:

1. **Understanding Goitre**:
- Goitre is defined as the enlargement of the thyroid gland. It can occur due to various factors affecting the production of thyroid hormones (T3 and T4).

2. **Analyzing the Options**:
- **Grave's Disease**: This is an autoimmune disorder where the body's immune system stimulates the thyroid gland to produce more hormones, leading to enlargement (goitre). Thus, this can cause goitre.
- **Excessive Intake of Exogenous Thyroxine**: When a person takes too much external thyroxine (T4), it can actually suppress the production of TSH (Thyroid Stimulating Hormone) from the pituitary gland, which would prevent the thyroid gland from enlarging. Therefore, this does not cause goitre.
- **Iodine Deficiency**: Iodine is essential for the synthesis of thyroid hormones. A deficiency leads to reduced production of T3 and T4, which in turn causes the pituitary to secrete more TSH, resulting in goitre.
- **Pituitary Adenoma**: A pituitary adenoma can secrete excess TSH, which can stimulate the thyroid gland and lead to goitre.

3. **Conclusion**:
- The only option that does not lead to goitre is the **excessive intake of exogenous thyroxine**. This is because it does not stimulate the thyroid gland to enlarge but rather suppresses TSH production.

### Final Answer:
Goitre can occur as a consequence of all the following except **excessive intake of exogenous thyroxine**.

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