Endocrinology Practice Questions

Q: The most common cause of hyperthyroidism in a young female is?

Graves' disease. ***Graves' disease*** - This is an **autoimmune disorder** where antibodies stimulate the thyroid gland, leading to **overproduction of thyroid hormones** [1], [2]. - It is the **most common cause of hyperthyroidism** in young to middle-aged women, making it highly probable in a young female patient [1], [2]. *Toxic multinodular goiter* - This condition is characterized by **multiple nodules** within the thyroid gland that autonomously produce thyroid hormones. - While a cause of hyperthyroidism, it is **more common in older individuals**, typically those over 50 years of age. *Subacute thyroiditis* - This is a **self-limiting inflammatory condition** of the thyroid often following a viral infection, causing a transient hyperthyroid phase due to the release of preformed hormones. - It presents with **painful thyroid enlargement** and is usually followed by a hypothyroid phase, which is different from sustained hyperthyroidism. *TSH-secreting pituitary adenoma* - This is a **very rare cause of hyperthyroidism** where a pituitary tumor produces excess **Thyroid-Stimulating Hormone (TSH)**, leading to thyroid overstimulation. - It is often accompanied by other symptoms of a pituitary mass like **headaches or visual field defects**, which are not implied here.

Q: A 20-year-old female presents with increasing hair growth on her face and chest, deepening of her voice, and acne over the past year. She has no history of other medical problems. On examination, she has acne, abnormal male pattern balding, and enlargement of her clitoris. Blood tests show normal serum testosterone levels but a markedly elevated level of dihydroepiandrosterone sulphate. What is the most likely diagnosis?

Adrenal Tumor. ***Adrenal Tumor*** - The combination of **rapid onset virilization** (deepening voice, male pattern balding, clitoromegaly) and **markedly elevated DHEAS** points strongly to an adrenal source of androgens, typically an adrenal tumor. - **DHEAS** is almost exclusively produced by the **adrenal glands**, making its high levels a key indicator of adrenal pathology [1]. *Polycystic Ovary Syndrome (PCOS)* - While PCOS can cause **hirsutism** and **acne**, it usually presents with milder virilization and elevated testosterone, not typically with severe features like **clitoromegaly** or significantly elevated DHEAS [1]. - The onset in PCOS is usually more gradual, and **DHEAS levels** are typically normal or only mildly elevated, with **testosterone** being the predominant elevated androgen [1]. *Ovarian Tumor* - Ovarian tumors can cause **virilization** due to androgen production, but they primarily lead to **elevated testosterone levels**, not usually markedly elevated DHEAS [1]. - The **rapid progression of virilization** could be consistent with an ovarian tumor, but the specific DHEAS elevation makes an adrenal source more likely. *Drug Induced Adverse Effects* - Certain medications can cause symptoms like **acne** or **hirsutism**, but it's rare for drugs to induce such a full spectrum of **virilization** including **clitoromegaly** and **deepening voice** without other clear drug history. - Drug-induced virilization would not specifically cause a **markedly elevated DHEAS** level with normal testosterone, which points to an endogenous androgen-producing pathology.

Q: A middle-aged female presents with increasing visual loss, breast enlargement, and irregular menses. What is the most appropriate investigation to diagnose the underlying condition?

S. prolactin. ***S. prolactin*** - **Hyperprolactinemia** is the most likely cause of the presented symptoms: **galactorrhea** (**breast enlargement** with milk production), **amenorrhea** (**irregular menses**), and **visual field defects** due to a pituitary tumor compressing the optic chiasm [1]. - Measuring serum prolactin levels directly confirms or rules out **hyperprolactinemia**, guiding further management, including imaging of the pituitary gland if elevated [1]. *S. calcitonin* - **Calcitonin** is a hormone primarily involved in **calcium regulation** and is typically elevated in medullary thyroid carcinoma. - The presented symptoms (visual loss, breast enlargement, irregular menses) are not characteristic of elevated calcitonin levels or a **medullary thyroid carcinoma**. *S. hemoglobin concentration* - **Hemoglobin concentration** measures the amount of oxygen-carrying protein in red blood cells and is used to diagnose **anemia** or polycythemia. - While general labs might include this, it is not directly relevant to the specific constellation of symptoms pointing towards an **endocrine or pituitary issue**. *S. calcium* - **Serum calcium** levels are checked for disorders of calcium metabolism, such as **hyperparathyroidism** or hypocalcemia. - Though calcium is regulated by hormones, the symptoms of **visual loss**, **breast enlargement**, and **menstrual irregularities** are not typically associated with primary disturbances in calcium levels.

Q: All of the following are features of hypothyroidism except which of the following?

Lid retraction. ***Lid retraction*** - **Lid retraction** is a characteristic feature of **hyperthyroidism** (e.g., Graves' disease), not hypothyroidism [1]. - It results from increased sympathetic stimulation of the **Müller's muscle** and/or superior rectus muscle overactivity. *Cold intolerance* - **Cold intolerance** is a common symptom of **hypothyroidism** due to a reduced metabolic rate and decreased heat production [2]. - The body's ability to maintain core temperature is impaired, leading to increased sensitivity to cold environments. *Dry skin* - **Dry, scaly skin** (xerosis) is a frequent manifestation of **hypothyroidism**. - It is caused by decreased sebaceous and sweat gland activity, as well as changes in epidermal cell turnover. *Myxedema* - **Myxedema** refers to the characteristic non-pitting edema seen in severe or long-standing **hypothyroidism** [2]. - It results from the accumulation of **glycosaminoglycans** (e.g., hyaluronic acid) in the interstitial spaces, leading to swelling, particularly in the face, hands, and feet [1].

Q: Which of the following is NOT consistent with pheochromocytoma?

Episodic diarrhea. Episodic diarrhea - While pheochromocytoma can cause gastrointestinal symptoms due to **catecholamine excess**, **diarrhea** is not a classic or consistent feature; constipation or abdominal pain are more commonly reported. - **Vasoactive intestinal peptide (VIP)**-secreting tumors (VIPomas) are more typically associated with chronic watery diarrhea [1]. *Episodic flushing of skin* - **Flushing** can occur in pheochromocytoma due to the **vasodilatory effects** of excessive catecholamines, particularly epinephrine. - It's a common symptom often seen alongside other classic paroxysmal episodes. *Paroxysm, palpitation and sweating* - These are classic components of the **"PHEochromocytoma triad"**: **Palpitations**, **Headache**, and **Episodic sweating**, commonly occurring in paroxysms. - They result directly from the release of large amounts of **norepinephrine and epinephrine** from the tumor. *Episodes of hypertension* - **Episodic or paroxysmal hypertension** is a hallmark symptom of pheochromocytoma, caused by the sudden surge of catecholamines leading to vasoconstriction. - This can manifest as severe, sudden increases in blood pressure, often accompanied by other symptoms like headache and palpitations.

Q: Which of the following glands is NOT involved in Type I MEN?

Adrenal. ***Adrenal*** - The **adrenal glands** are predominantly involved in **Multiple Endocrine Neoplasia type 2 (MEN2)**, particularly with pheochromocytomas, rather than MEN type 1. - While adrenal lesions (e.g., adenomas, hyperplasia) can occur sporadically or rarely in MEN1, they are not considered a primary or core component of the MEN1 syndrome as defined by the classic "3 Ps." [1] *Pancreas* - The **pancreas** is a primary gland involved in MEN1, frequently developing **neuroendocrine tumors** (e.g., gastrinomas, insulinomas). - These pancreatic tumors are a major cause of morbidity and mortality in MEN1 patients. *Pituitary* - The **pituitary gland** is one of the classic "3 P's" involved in MEN1, commonly developing **adenomas**, especially **prolactinomas**. [1] - These pituitary tumors can cause hormonal imbalances and mass effects within the sella turcica. *Parathyroid* - The **parathyroid glands** are almost universally involved in MEN1, with **hyperplasia** leading to **primary hyperparathyroidism**. [1] - This is often the earliest and most common clinical manifestation of MEN1.

Q: Most common cause of Cushing's syndrome is what?

Pituitary adenoma. ***Pituitary adenoma*** - The **most common cause** of Cushing's syndrome, specifically **Cushing's disease**, is excess ACTH production from a pituitary adenoma [1]. - This leads to **overstimulation of the adrenal glands**, resulting in increased cortisol production [1]. *McCune Albright syndrome* - It is a genetic disorder characterized by **fibrous dysplasia**, **café-au-lait spots**, and **endocrine problems**, not primarily Cushing's syndrome. - Though hormone abnormalities may present, it is not the **most common** cause of Cushing's syndrome. *Adrenal carcinoma* - While adrenal carcinoma can cause **Cushing's syndrome**, it is less common compared to the **pituitary adenoma** [1]. - This malignant tumor is rare and typically presents with more aggressive features and higher cortisol levels. *Adrenal adenoma* - Adrenal adenomas are benign tumors that can produce **excess cortisol**, but they are not the leading cause of Cushing's syndrome overall [1]. - They account for a smaller proportion of cases compared to **pituitary adenomas**.

Q: Which of the following conditions is least likely to cause weight loss?

Insulinoma. ***Insulinoma*** - An **insulinoma** is a tumor of the pancreatic beta cells that secretes excessive insulin, leading to **hypoglycemia**. - While patients may experience weight gain due to frequent eating to counteract hypoglycemic episodes, significant weight loss is **uncommon** and not a primary feature [1]. *Pheochromocytoma* - **Pheochromocytoma** is a tumor that secretes high levels of **catecholamines** (epinephrine and norepinephrine), which increase metabolic rate. - This increased metabolism often leads to significant **weight loss**, along with symptoms like hypertension, palpitations, and sweating. *Adrenal insufficiency* - **Adrenal insufficiency** (Addison's disease) is characterized by decreased production of cortisol and aldosterone, leading to chronic GI symptoms, weakness, and **anorexia**. - Patients often experience **unexplained weight loss** due to nausea, vomiting, and loss of appetite. *Uremia* - **Uremia** refers to the accumulation of urea and other nitrogenous waste products in the blood, typically seen in advanced **kidney failure**. - It often causes symptoms like **anorexia**, nausea, vomiting, and a metallic taste in the mouth, all of which contribute to significant **weight loss**.

Q: Hypercalcemia is not a feature of which one of the following conditions?

Tumor lysis syndrome. Tumor lysis syndrome is characterized by the rapid breakdown of tumor cells, leading to the release of intracellular contents. This typically causes **hyperkalemia**, **hyperphosphatemia**, and **hyperuricemia**, but generally **hypocalcemia** due to phosphate binding [3], not hypercalcemia. *Primary hyperparathyroidism* - This condition involves excessive production of **parathyroid hormone (PTH)**, which leads to increased bone resorption, increased renal calcium reabsorption, and increased vitamin D activation, all contributing to **hypercalcemia** [1], [4]. - It is a common cause of isolated elevated calcium levels, often discovered incidentally [2]. *Multiple myeloma* - Multiple myeloma is a plasma cell malignancy that causes extensive **bone destruction** through the release of osteoclast-activating factors. - This increased bone resorption leads to a significant release of calcium into the bloodstream, resulting in **hypercalcemia** [1]. *Sarcoidosis* - Sarcoidosis is a granulomatous disease where activated macrophages in the granulomas produce **1,25-dihydroxyvitamin D** (calcitriol). - This excess calcitriol leads to increased intestinal absorption of calcium and increased bone resorption, causing **hypercalcemia** [1].

Q: A hypertensive patient who is a chronic smoker presented with recurrent hemoptysis, and on examination, he had cushingoid features. Investigations revealed raised ACTH levels that were not suppressed by dexamethasone. The single diagnosis that can account for all his symptoms is

Ectopic ACTH-producing tumor. ***Ectopic ACTH-producing tumor*** - The combination of **Cushingoid features**, **recurrent hemoptysis** (suggesting a lung tumor), **hypertension**, elevated **ACTH levels**, and non-suppressibility by **dexamethasone** strongly points to an **ectopic ACTH-producing tumor**, most commonly a small cell lung carcinoma [1], [2]. - The patient's **chronic smoking history** further increases the likelihood of a paraneoplastic syndrome associated with lung cancer. *Multiple endocrine neoplasia type I* - MEN 1 involves tumors of the parathyroid glands, pituitary gland, and pancreas, leading to symptoms like **hypercalcemia**, **acromegaly**, or **Zollinger-Ellison syndrome**. - While pituitary tumors can cause Cushing's disease, the **hemoptysis** and **chronic smoking history** are not typical features of MEN 1. *Adrenocortical adenoma* - An **adrenocortical adenoma** would cause **Cushing's syndrome** due to primary adrenal cortisol overproduction, leading to **suppressed ACTH levels** rather than elevated levels [1], [2]. - It would not explain the **hemoptysis** or the non-suppressibility of ACTH by dexamethasone. *Cushing's disease due to pituitary adenoma* - **Cushing's disease** is caused by a **pituitary adenoma** secreting ACTH, leading to elevated ACTH and cortisol levels [1]. - While it causes **Cushingoid features** and **hypertension**, it would typically show partial suppression of **ACTH** with high-dose dexamethasone and does not explain the **hemoptysis**.

Question 1

The most common cause of hyperthyroidism in a young female is?

Accepted Answer

Graves' disease

Answer

TSH-secreting pituitary adenoma

Answer

Subacute thyroiditis

Answer

Toxic multinodular goiter

Question 2

A 20-year-old female presents with increasing hair growth on her face and chest, deepening of her voice, and acne over the past year. She has no history of other medical problems. On examination, she has acne, abnormal male pattern balding, and enlargement of her clitoris. Blood tests show normal serum testosterone levels but a markedly elevated level of dihydroepiandrosterone sulphate. What is the most likely diagnosis?

Accepted Answer

Adrenal Tumor

Answer

Polycystic Ovary Syndrome (PCOS)

Answer

Ovarian Tumor

Answer

Drug Induced Adverse Effects

Question 3

A middle-aged female presents with increasing visual loss, breast enlargement, and irregular menses. What is the most appropriate investigation to diagnose the underlying condition?

Accepted Answer

S. prolactin

Answer

S. calcitonin

Answer

S. hemoglobin concentration

Answer

S. calcium

Question 4

All of the following are features of hypothyroidism except which of the following?

Accepted Answer

Lid retraction

Answer

Dry skin

Answer

Myxedema

Answer

Cold intolerance

Question 5

Which of the following is NOT consistent with pheochromocytoma?

Accepted Answer

Episodic diarrhea

Answer

Paroxysm, palpitation and sweating

Answer

Episodic flushing of skin

Answer

Episodes of hypertension

Question 6

Which of the following glands is NOT involved in Type I MEN?

Accepted Answer

Adrenal

Answer

Parathyroid

Answer

Pituitary

Answer

Pancreas

Question 7

Most common cause of Cushing's syndrome is what?

Accepted Answer

Pituitary adenoma

Answer

Adrenal adenoma

Answer

Adrenal carcinoma

Answer

McCune Albright syndrome

Question 8

Which of the following conditions is least likely to cause weight loss?

Accepted Answer

Insulinoma

Answer

Pheochromocytoma

Answer

Adrenal insufficiency

Answer

Uremia

Question 9

Hypercalcemia is not a feature of which one of the following conditions?

Accepted Answer

Tumor lysis syndrome

Answer

Primary hyperparathyroidism

Answer

Multiple myeloma

Answer

Sarcoidosis

Question 10

A hypertensive patient who is a chronic smoker presented with recurrent hemoptysis, and on examination, he had cushingoid features. Investigations revealed raised ACTH levels that were not suppressed by dexamethasone. The single diagnosis that can account for all his symptoms is

Accepted Answer

Ectopic ACTH-producing tumor

Answer

Adrenocortical adenoma

Answer

Multiple endocrine neoplasia type I

Answer

Cushing's disease due to pituitary adenoma

Endocrinology — MCQs

Endocrinology — MCQs

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