Endocrinology — MCQs

A 35-year-old female with a history of diabetes presents with a painless neck swelling that moves with swallowing. She also reports constipation, weight gain, hoarseness, oligomenorrhea, and mild paresthesias. Examination reveals bradycardia, cold extremities, non-pitting edema, and delayed relaxation of deep tendon reflexes. Thyroid function tests show high TSH and low unbound T4 levels. Laboratory workup also reveals positive thyroid peroxidase antibodies, consistent with autoimmune thyroiditis. Given this condition, which type of cancer is she at risk of developing?

Q1729

All of the following can cause osteoporosis, except which of the following?

Q1730

Which of the following is not a known cause of osteoporosis?

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 1721: A 50-year-old man with advanced tuberculosis and signs of severe acute adrenal insufficiency should be treated immediately with a combination of:

A. Triamcinolone and dexamethasone
B. Dexamethasone and metyrapone
C. Aldosterone and fludrocortisone
D. Cortisol and fludrocortisone (Correct Answer)

Explanation: ***Cortisol and fludrocortisone*** - **Cortisol** (a **glucocorticoid**) is essential to replace the deficient hormone in acute adrenal insufficiency, addressing symptoms like **hypotension** and **hypoglycemia** [1], [2]. - **Fludrocortisone** (a **mineralocorticoid**) is also critical as patients with primary adrenal insufficiency (such as that caused by advanced tuberculosis) have deficient **aldosterone** production, requiring mineralocorticoid replacement [1]. *Aldosterone and fludrocortisone* - **Aldosterone** is the natural mineralocorticoid, but it's not administered directly as a drug in this context; instead, **fludrocortisone** is used for its mineralocorticoid effects. - While fludrocortisone is appropriate, aldosterone alone would not address the critical glucocorticoid deficiency seen in acute adrenal crisis [1]. *Triamcinolone and dexamethasone* - Both **triamcinolone** and **dexamethasone** are potent **glucocorticoids** but lack significant mineralocorticoid activity. - In acute adrenal insufficiency, both glucocorticoid and mineralocorticoid replacement are crucial, making this combination insufficient [1]. *Dexamethasone and metyrapone* - **Dexamethasone** is a potent **glucocorticoid** but, like **triamcinolone**, lacks sufficient mineralocorticoid activity for complete replacement [1]. - **Metyrapone** is an adrenal enzyme inhibitor used to reduce cortisol production, making it contraindicated in adrenal insufficiency, where cortisol levels are already dangerously low.

Question 1722: An obese female patient presented with hypertension, chronic headache, and normal pituitary function. The most likely diagnosis is

A. Cushing's disease
B. prolactinoma
C. Hypothyroidism
D. Empty Sella Syndrome (Correct Answer)

Explanation: Empty Sella Syndrome - This condition involves herniation of the arachnoid and CSF into the sella turcica, compressing the **pituitary gland**. While the pituitary gland is compressed, its function is often preserved, hence **normal pituitary function**. - Often associated with **obesity**, **hypertension**, and **headaches** (including chronic headaches) due to increased intracranial pressure. *Cushing's disease* - Characterized by **pituitary adenoma** secreting excess **ACTH**, leading to **hypercortisolism**. [1], [2] - Symptoms include central obesity, hypertension, and headaches, but would present with **abnormal pituitary function** (elevated ACTH and cortisol). [1] *Prolactinoma* - A **pituitary tumor** that secretes excessive **prolactin**, causing symptoms like galactorrhea, amenorrhea (in women), and hypogonadism. - While it can cause headaches, it typically leads to **abnormal pituitary function** with elevated prolactin levels, which is not mentioned here. *Hypothyroidism* - A condition caused by **underproduction of thyroid hormones**, leading to symptoms like weight gain, fatigue, cold intolerance, and bradycardia. - While it can be associated with weight gain and some headaches, it does not typically cause **hypertension** as a primary symptom related to the thyroid, and would present with **abnormal thyroid function tests**, not normal pituitary function.

Question 1723: What is the most appropriate insulin regimen for achieving tight control of blood sugar levels in a 20-year-old male with type 1 diabetes mellitus?

A. Morning injections of insulin detemir with insulin aspart at mealtimes. (Correct Answer)
B. Morning injection of NPH insulin and evening injection of regular insulin.
C. Morning injections of insulin lispro with evening injections of insulin glulisine.
D. Evening injections of mixed regular insulin and insulin glargine for basal control.

Explanation: **Morning injections of insulin detemir with insulin aspart at mealtimes.** - This regimen involves a **long-acting basal insulin (insulin detemir)** to provide continuous background insulin coverage and a **rapid-acting insulin (insulin aspart)** to cover carbohydrate intake at meals, allowing for **tight glycemic control** and flexibility [1]. - This approach closely mimics the body's natural insulin secretion patterns, which is critical for managing **Type 1 Diabetes Mellitus** effectively in a young, active individual [1]. *Morning injection of NPH insulin and evening injection of regular insulin.* - **NPH insulin** is an intermediate-acting insulin with a less predictable peak and duration compared to long-acting analogs, making **tight control** more challenging due to increased risk of hypoglycemia and hyperglycemia. - Using **regular insulin** for the evening, without specific mealtime dosing, is less flexible and precise for managing postprandial glucose excursions compared to rapid-acting insulins. *Morning injections of insulin lispro with evening injections of insulin glulisine.* - Both **insulin lispro** and **insulin glulisine** are rapid-acting insulins designed to be taken with meals; using them as basal insulin without a separate long-acting component would lead to **poor basal control** and a high risk of hypoglycemia. - This regimen lacks a proper **basal insulin** component, which is essential for maintaining fasting glucose levels and preventing hyperglycemia between meals. *Evening injections of mixed regular insulin and insulin glargine for basal control.* - **Regular insulin** is a short-acting insulin and not suitable for basal control; its inclusion in a mixed dose for basal control would lead to significant fluctuations and difficulties in achieving stable glucose levels. - While **insulin glargine** is a good basal insulin, mixing it with regular insulin is generally not recommended as it can alter the **pharmacokinetic profile** of both insulins and complicate dosing [1].

Question 1724: A physician is evaluating a patient with hypogonadotropic hypogonadism and anosmia. What condition is most likely suspected in this scenario?

A. Asherman's syndrome
B. Stein-Leventhal syndrome
C. Sheehan's syndrome
D. Kallmann syndrome (Correct Answer)

Explanation: ***Kallmann syndrome*** - This syndrome is characterized by **hypogonadotropic hypogonadism** (due to GnRH deficiency) combined with **anosmia** (impaired sense of smell) or hyposmia [1]. - The anosmia results from the **agenesis or hypoplasia of the olfactory bulbs and tracts**, which is a key diagnostic feature. *Asherman's syndrome* - This condition is characterized by **intrauterine adhesions** or synechiae, usually occurring after uterine surgery or infection. - It primarily causes **secondary amenorrhea** and infertility but does not involve hypogonadotropic hypogonadism or anosmia. *Stein-Leventhal syndrome* - This is an older term for **Polycystic Ovary Syndrome (PCOS)**, characterized by **anovulation**, hyperandrogenism, and polycystic ovaries [1]. - It is associated with **insulin resistance** and metabolic dysfunction but not anosmia or hypogonadotropic hypogonadism. *Sheehan's syndrome* - This is a form of **hypopituitarism** caused by **ischemic necrosis of the pituitary gland** following severe postpartum hemorrhage [1]. - It leads to deficiencies in various pituitary hormones, including gonadotropins, but it is typically acute postpartum and does not present with anosmia.

Question 1725: Which of the following is the MOST specific finding in primary hypothyroidism?

A. Low T3
B. Low triglycerides
C. High TSH (Correct Answer)
D. High cholesterol

Explanation: ***High TSH*** - A **high TSH** (thyroid-stimulating hormone) is the most specific indicator of **primary hypothyroidism** because it reflects the pituitary gland's attempt to stimulate a failing thyroid gland [1]. - In primary hypothyroidism, the thyroid gland itself is unable to produce sufficient thyroid hormones, leading to a feedback mechanism that increases TSH secretion [1]. *Low T3* - While **low T3** (triiodothyronine) can be seen in hypothyroidism, it is often the last thyroid hormone to decrease significantly and can be associated with other conditions, such as **euthyroid sick syndrome** [1]. - Therefore, low T3 is less specific for diagnosing primary hypothyroidism than TSH levels [1]. *Low triglycerides* - **Hypothyroidism** is typically associated with **hyperlipidemia**, including **elevated triglycerides**, due to decreased catabolism of lipoproteins. - Thus, low triglycerides would be an unexpected finding in primary hypothyroidism. *High cholesterol* - **High cholesterol** is a common finding in **hypothyroidism** due to reduced clearance of LDL cholesterol [2]. - However, high cholesterol is a non-specific finding and can be caused by many other factors, such as diet, genetics, and other metabolic syndromes, making it less specific for hypothyroidism compared to TSH.

Question 1726: What is the fasting blood glucose level that confirms a diagnosis of diabetes mellitus?

A. >200
B. <100
C. ≥126 (Correct Answer)
D. 101-125

Explanation: ≥126 - A fasting plasma glucose (FPG) level of ≥126 mg/dL on two separate occasions is a diagnostic criterion for diabetes mellitus [1]. - This threshold indicates persistent hyperglycemia beyond what is considered normal. <100 - A fasting plasma glucose level <100 mg/dL is considered normal and does not indicate diabetes or prediabetes [1]. - This range reflects healthy glucose regulation in the body. 101-125 - A fasting plasma glucose level between 100-125 mg/dL indicates prediabetes or impaired fasting glucose (IFG) [1]. - While not diabetes, it signifies an increased risk for developing type 2 diabetes. >200 - A random plasma glucose (RPG) level >200 mg/dL with classic symptoms of diabetes (e.g., polyuria, polydipsia, unexplained weight loss) can confirm diabetes [1]. - However, for a fasting blood glucose alone to confirm diabetes, it needs to be ≥126 mg/dL, and a level >200 mg/dL would be an even more severe manifestation.

Question 1727: Hypothyroidism with an increased TSH level is seen in all except which of the following?

A. Sheehan's syndrome (Correct Answer)
B. Post radioiodine ablation
C. Endemic goitre
D. Lithium carbonate therapy

Explanation: ***Sheehan's syndrome*** - Sheehan's syndrome is a cause of **secondary hypothyroidism** [4], meaning the problem lies in the **pituitary gland's inability to produce TSH**, leading to low TSH and low thyroid hormones. - In this condition, the TSH level would be **low or inappropriately normal**, not increased, as the pituitary is damaged [2]. *Lithium carbonate therapy* - Lithium can **inhibit thyroid hormone release** and synthesis, leading to **primary hypothyroidism** where the thyroid gland is the culprit. - This results in a feedback loop that causes the pituitary to produce **increased TSH** to try and stimulate the failing thyroid [1]. *Post radioiodine ablation* - Radioiodine ablation **destroys thyroid cells**, leading to a direct inability of the thyroid gland to produce sufficient hormones. - This condition mimics spontaneous primary hypothyroidism, causing the pituitary to release **increased TSH** in an attempt to stimulate the damaged thyroid [1][3]. *Endemic goitre* - Endemic goitre is often caused by **iodine deficiency**, which impairs the thyroid's ability to synthesize thyroid hormones. - This is a form of **primary hypothyroidism** leading to **increased TSH** as the pituitary tries to compensate for the low thyroid hormone levels [1].

Question 1728: A 35-year-old female with a history of diabetes presents with a painless neck swelling that moves with swallowing. She also reports constipation, weight gain, hoarseness, oligomenorrhea, and mild paresthesias. Examination reveals bradycardia, cold extremities, non-pitting edema, and delayed relaxation of deep tendon reflexes. Thyroid function tests show high TSH and low unbound T4 levels. Laboratory workup also reveals positive thyroid peroxidase antibodies, consistent with autoimmune thyroiditis. Given this condition, which type of cancer is she at risk of developing?

A. Papillary thyroid carcinoma (Correct Answer)
B. Follicular thyroid carcinoma
C. Anaplastic thyroid carcinoma
D. Medullary thyroid carcinoma

Explanation: ***Papillary thyroid carcinoma*** - The patient's **TSH elevation**, low T4, and presence of **TPO antibodies** suggests Hashimoto's thyroiditis, which is associated with a higher risk of developing papillary thyroid carcinoma. - Symptoms such as a **firm thyroid nodule** and hoarseness raise suspicion for malignancy, especially in the context of autoimmune thyroid disease. *Follicular thyroid carcinoma* - Typically presents with **cold nodules** on radioactive iodine uptake and is less associated with autoimmune conditions than papillary carcinoma. - The clinical and laboratory features presented are more indicative of **papillary thyroid carcinoma** rather than follicular. *Anaplastic thyroid carcinoma* - Typically presents in older patients, often with a **rapidly enlarging neck mass** and significant **symptoms of obstruction**. - This case lacks key features like aggressive clinical presentation and is more consistent with **differentiated thyroid cancers**. [1] *Medullary thyroid carcinoma* - Arises from **C-cells (parafollicular cells)** and may be associated with **MEN syndromes**. - Not related to **TSH/T4 levels** or autoimmune thyroid conditions, and typically presents with **elevated calcitonin levels**.

Question 1729: All of the following can cause osteoporosis, except which of the following?

A. Steroids
B. Fluorosis (Correct Answer)
C. Thyrotoxicosis
D. Hyperparathyroidism

Explanation: ***Fluorosis*** - **Fluorosis** is a condition caused by excessive fluoride intake, which leads to **increased bone density** (osteosclerosis) and abnormal bone formation, not osteoporosis. - While it can cause bone pain and weakness, its characteristic effect is **hardening of bones**, making them brittle but denser, rather than porous. *Steroids* - Prolonged use of **glucocorticoids (steroids)** is a common cause of secondary osteoporosis [1]. - They decrease osteoblast activity and increase osteoclast activity, leading to **reduced bone formation** and **increased bone resorption** [1]. *Thyrotoxicosis* - **Thyrotoxicosis**, or hyperthyroidism, causes an increase in bone turnover with a greater increase in **bone resorption** than formation. - This imbalance results in **net bone loss** and can lead to osteoporosis. *Hyperparathyroidism* - **Primary hyperparathyroidism** leads to excessive secretion of parathyroid hormone (PTH), which continuously stimulates osteoclasts. - This results in **increased bone resorption**, particularly from cortical bone, causing osteoporosis.

Question 1730: Which of the following is not a known cause of osteoporosis?

A. Sarcoidosis
B. Old age
C. Hypoparathyroidism (Correct Answer)
D. Steroid therapy

Explanation: ### Hypoparathyroidism - This condition leads to **low parathyroid hormone (PTH)** levels, resulting in **decreased serum calcium** and **increased serum phosphate**. - While it can affect bone metabolism, severe cases typically present with **increased bone mineral density** or **osteosclerosis**, not osteoporosis, due to reduced bone resorption. *Sarcoidosis* - This granulomatous disease can cause **hypercalcemia** due to extrarenal production of **calcitriol** (1,25-dihydroxyvitamin D) by activated macrophages. - The resulting hypercalcemia and prolonged high calcitriol levels can lead to **increased bone turnover** and **osteoporosis** [4]. *Old age* - Bone density naturally declines with age, especially after menopause in women due to **estrogen deficiency** [3]. - This age-related bone loss is a primary factor in the development of **primary osteoporosis** [2]. *Steroid therapy* - **Glucocorticoid-induced osteoporosis** is a common cause of secondary osteoporosis [1]. - Steroids decrease osteoblast activity, increase osteoclast activity, and impair calcium absorption, all contributing to **bone loss** [1].

Practice by Chapter

Diabetes Mellitus

Practice Questions

Thyroid Disorders

Practice Questions

Adrenal Gland Disorders

Practice Questions

Pituitary Disorders

Practice Questions

Calcium and Bone Metabolism

Practice Questions

Reproductive Endocrinology

Practice Questions

Lipid Disorders

Practice Questions

Endocrine Hypertension

Practice Questions

Multiple Endocrine Neoplasia

Practice Questions

Obesity and Metabolic Syndrome

Practice Questions

Neuroendocrine Tumors

Practice Questions

Endocrine Emergencies

Practice Questions

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