A 45-year-old male patient presents with complaints of severe headaches, visual disturbances, and joint pain. Upon further investigation, he is diagnosed with hyperpituitarism. Which of the following is the most likely underlying cause of his symptoms?

Choice A Reason:

An adenoma of the parathyroid gland is the most common cause of primary hyperparathyroidism. This benign tumor leads to the overproduction of parathyroid hormone (PTH), which in turn causes elevated calcium levels in the blood. The excessive PTH secretion disrupts the normal calcium balance, leading to symptoms such as fatigue, muscle weakness, and depression. Parathyroid adenomas account for approximately 80% of primary hyperparathyroidism cases.

Choice B Reason:

Thyroid carcinoma is a type of cancer that originates in the thyroid gland, not the parathyroid glands. While thyroid carcinoma can cause various symptoms, it does not typically lead to elevated PTH levels or hyperparathyroidism. Therefore, it is not the most likely cause of the patient’s condition.

Choice C Reason:

Vitamin D deficiency can lead to secondary hyperparathyroidism, where low levels of vitamin D cause decreased calcium absorption, prompting the parathyroid glands to produce more PTH to maintain calcium levels. However, this condition is usually associated with low or normal calcium levels, not elevated calcium levels as seen in this patient. Therefore, it is not the most likely cause of her hyperparathyroidism.

Choice D Reason:

Chronic kidney disease (CKD) can also cause secondary hyperparathyroidism due to impaired kidney function, which affects calcium and phosphate balance and vitamin D metabolism. However, similar to vitamin D deficiency, CKD-related hyperparathyroidism typically presents with low or normal calcium levels rather than elevated levels. Thus, it is not the most likely cause in this scenario.

Choice A Reason:

Methimazole is an antithyroid medication that inhibits the synthesis of thyroid hormones. It is commonly used to manage hyperthyroidism, especially in patients who are not candidates for radioactive iodine therapy or surgery. Methimazole is effective in reducing thyroid hormone levels and controlling symptoms, but it requires long-term use and regular monitoring of thyroid function tests.

Choice B Reason:

Levothyroxine is a synthetic form of thyroxine (T4) used to treat hypothyroidism, not hyperthyroidism. Administering levothyroxine to a patient with hyperthyroidism would exacerbate the condition by increasing thyroid hormone levels. Therefore, it is not an appropriate treatment for managing hyperthyroidism.

Choice C Reason:

Radioactive iodine is a widely used treatment for hyperthyroidism. It works by destroying overactive thyroid cells, thereby reducing the production of thyroid hormones. This treatment is particularly effective for patients with Graves’ disease, toxic multinodular goiter, or toxic adenoma. Radioactive iodine is a definitive treatment that can lead to a permanent resolution of hyperthyroidism, although it may result in hypothyroidism, which can be managed with levothyroxine.

Choice D Reason:

Propranolol is a beta-blocker that helps manage the symptoms of hyperthyroidism, such as palpitations, tremors, and anxiety. While it is useful for symptomatic relief, it does not address the underlying cause of hyperthyroidism. Propranolol is often used in conjunction with other treatments, such as antithyroid medications or radioactive iodine, to provide immediate symptom control.