Endocrinology Practice Questions

Q: A 55-year-old postmenopausal woman presents with chronic low backache of 6 months duration. She has no history of trauma. What is the most likely diagnosis?

Osteoporosis. ***Osteoporosis*** - **Postmenopausal women** are at a high risk of developing osteoporosis due to **estrogen deficiency**, which leads to accelerated bone loss [1]. - **Chronic low backache** without trauma in this demographic suggests **vertebral compression fractures**, a common complication of osteoporosis [1]. *Hurler's syndrome* - This is a **lysosomal storage disorder** (mucopolysaccharidosis type I) that manifests in **childhood** with skeletal deformities, coarse facial features, and developmental delays. - It would not present as new-onset chronic low backache in a 55-year-old adult. *Paget’s disease* - Paget's disease involves **localized abnormal bone remodeling**, leading to enlarged and weakened bones [2]. - While it can cause bone pain, it's characterized by elevated **alkaline phosphatase** and often affects the pelvis, skull, or long bones, and a simple low backache presentation in a postmenopausal woman points more strongly to osteoporosis [2], [3]. *Renal osteodystrophy* - This condition is a complication of **chronic kidney disease**, resulting from imbalances in calcium, phosphate, parathyroid hormone, and vitamin D metabolism. - It would require a history of **renal dysfunction** and the low backache would likely be accompanied by other symptoms of kidney failure or bone pain related to specific lesions, which are not mentioned.

Q: A 32-year-old woman complains of amenorrhea since the delivery of a baby 15 months previously, despite the fact that she did not breastfeed her baby. The delivery was complicated by excessive hemorrhage that required a transfusion of 2.5 liters of blood. She has also been fatigued and has gained an additional 4.5Kg since the baby was born. Laboratory data show the following: Serum LH < 1 IU/L (normal, 4-24 IU/L) Serum estradiol 5 pg/mL (normal, 20 - 100 pg/mL) Serum TSH 0.1 mU/L (normal, 0.5 - 5 mU/L) Serum GH 3 ng/mL (normal, < 5 ng/mL) Serum ACTH 28 pg/mL (normal, 10 - 50 pg/mL) Serum prolactin 2 ng/mL (normal, < 20 ng/mL). Injection of 500 μg of TRH failed to produce the expected rise in both serum TSH and prolactin. Which of the following diagnoses most likely explains the findings in this patient?

Hypopituitarism due to Sheehan's syndrome. ### Hypopituitarism due to Sheehan's syndrome - The patient's history of **postpartum hemorrhage** followed by amenorrhea, fatigue, and weight gain, along with low levels of **LH**, **estradiol**, **TSH**, and **prolactin**, despite normal ACTH and GH, points towards anterior pituitary dysfunction due to **ischemic necrosis** caused by Sheehan's syndrome [1]. - The failure of **TRH stimulation** to increase TSH and prolactin further supports a pituitary origin, as the pituitary is unable to respond due to damage. ### Hashimoto's thyroiditis - This condition primarily causes **hypothyroidism**, characterized by elevated TSH and low thyroid hormones, which is inconsistent with the patient's low TSH. - It does not explain the **gonadotropin deficiency** (low LH and estradiol) or the history of postpartum hemorrhage leading to multi-hormone deficiencies. ### Isolated gonadotropin deficiency - While the patient exhibits **amenorrhea** and low LH and estradiol, this diagnosis does not account for the **low TSH** [3] or the historical context of a severe postpartum hemorrhage. - Isolated gonadotropin deficiency does not explain the lack of TSH and prolactin response to TRH. ### Primary amenorrhea - This refers to the absence of menstruation by age 15 (with breast development) or 13 (without breast development) in a patient who has never menstruated, which is not applicable to a 32-year-old woman who has delivered a baby. - The patient's presentation is secondary amenorrhea, occurring after menarche and delivery, and is associated with other pan-hypopituitary features [4]. ### Pituitary apoplexy - Pituitary apoplexy typically presents with the **sudden onset** of severe headache, visual disturbances, and ophthalmoplegia due to acute hemorrhage or infarction of a pituitary adenoma. - This patient's symptoms are more chronic and progressive, evolving over 15 months, and lack the acute, severe presentation typical of apoplexy [2].

Q: Which one of the following statements about Graves' disease is FALSE?

Common in male. ***Common in male*** - Graves' disease is significantly **more common in females** than males, with a female-to-male ratio of approximately 7:1 [1]. It is a female predominant disease [2]. - The peak incidence is between the ages of 20 and 50 years, and it is the most common cause of **hyperthyroidism** in women [1], [2]. *Results in hyperthyroidism* - Graves' disease is characterized by the production of **autoantibodies** against the TSH receptor, leading to excessive stimulation of the thyroid gland [1]. - This overstimulation results in **increased synthesis and release of thyroid hormones**, causing a state of hyperthyroidism [2]. *Autoimmune disorder* - Graves' disease is a classic example of an **organ-specific autoimmune disease** [2]. - The immune system mistakenly produces antibodies that mimic the action of TSH, leading to thyroid overactivity [1]. *Referred to as toxic diffuse goiter* - The term "toxic" refers to the **hyperthyroid state** (thyrotoxicosis), and "diffuse goiter" describes the generally uniform enlargement of the entire thyroid gland [1]. - This terminology accurately reflects the typical presentation of Graves' disease, which involves an overactive, diffusely enlarged thyroid gland [2].

Q: Calcitonin levels increased in

Medullary thyroid carcinoma. Medullary thyroid carcinoma - Calcitonin is a hormone produced by the parafollicular C cells of the thyroid gland. - Medullary thyroid carcinoma is a neuroendocrine tumor arising from these C cells, leading to excessive and unregulated calcitonin production. Hyperparathyroidism - This condition involves increased production of parathyroid hormone (PTH), which acts to increase serum calcium levels [2]. - Calcitonin secretion is typically decreased or normal in hyperparathyroidism, as calcitonin works to lower serum calcium. Hypoparathyroidism - This condition is characterized by insufficient production of parathyroid hormone (PTH), leading to low serum calcium levels [1]. - Calcitonin levels are generally unaffected or may even be slightly decreased in response to the low calcium, as its primary role is to lower calcium. Cushing Syndrome - Cushing Syndrome is caused by prolonged exposure to high levels of cortisol, a glucocorticoid. - While cortisol can affect bone metabolism, it does not directly impact calcitonin production or secretion, which is primarily regulated by serum calcium levels and C-cell activity.

Q: In which condition is Chvostek's sign typically observed?

Hypoparathyroidism. Hypoparathyroidism - **Chvostek's sign** is a clinical manifestation of **hypocalcemia**, which is a hallmark of hypoparathyroidism [1]. - It involves a twitch of facial muscles elicited by tapping the **facial nerve** anterior to the ear. Hypercalcemia - **Hypercalcemia** is the opposite of hypocalcemia and would not cause increased neuromuscular excitability [2]. - Patients with hypercalcemia might experience symptoms like **fatigue**, **constipation**, and **bone pain** [2]. Insulinoma - An **insulinoma** is a tumor that produces excessive insulin, leading to **hypoglycemia**, not issues with calcium balance. - Symptoms are primarily related to low blood sugar, such as **confusion** and **tachycardia**. Diabetes mellitus - **Diabetes mellitus** is a metabolic disorder characterized by **high blood glucose levels** due to insulin deficiency or resistance. - It is not directly associated with calcium imbalances that would cause Chvostek's sign.

Q: Which of the following is NOT typically associated with Kallmann's syndrome?

Excess stimulation of the HPO axis. ***Excess stimulation of the HPO axis*** - Kallmann's syndrome is characterized by **hypogonadotropic hypogonadism**, meaning there is a deficiency in the secretion of **gonadotropin-releasing hormone (GnRH)** [1] from the hypothalamus. - This deficiency leads to *reduced* stimulation of the **hypothalamic-pituitary-ovarian (HPO)** axis, not excess stimulation. *Amenorrhea* - **Amenorrhea** (absence of menstruation) is a common presentation in females with Kallmann's syndrome due to the **hypogonadotropic hypogonadism**. - The lack of GnRH results in insufficient **follicle-stimulating hormone (FSH)** and **luteinizing hormone (LH)**, preventing ovarian function and regular menstrual cycles. *Hypogonadotropic hypogonadism* - This is a **defining feature** of Kallmann's syndrome, where the **hypothalamus fails to produce enough GnRH**, leading to low levels of FSH and LH from the pituitary. - The low gonadotropin levels subsequently cause the gonads (testes or ovaries) to produce insufficient sex hormones, resulting in **delayed or absent puberty** [1]. *Anosmia* - **Anosmia** (the inability to smell) is a classic and diagnostic feature of Kallmann's syndrome, distinguishing it from other forms of hypogonadotropic hypogonadism. - It occurs because the **GnRH-producing neurons** originate in the olfactory placode and fail to migrate correctly into the hypothalamus during embryonic development, disrupting both smell and GnRH secretion.

Q: Thyroid nodule in a 65 year old male who is clinically euthyroid is most likely to be

Follicular adenoma. ***Follicular adenoma*** - Typically presents as a **solitary, well-defined nodule** in euthyroid patients, making it a common finding in this demographic. - It is often **benign** and can be differentiated from malignancies through imaging and cytological evaluation. *Multinodular goiter* - Usually involves multiple nodules rather than a **single nodule**, and patients often present with thyroid dysfunction [1]. - More common in women, and does not fit the profile of a solitary nodule in a euthyroid male. *Follicular Carcinoma* - While it can present as a nodule, it typically involves **elevated risk factors** such as family history and certain genetic mutations. - Euthyroid status alone is insufficient for a diagnosis of malignancy without further alarming features. *Thyroid Cyst* - Cysts are usually **fluid-filled** and may not present as solid nodules, which are common in cases described. - They tend to be **asymptomatic** and are generally **benign**, lacking the solid characteristics of a follicular adenoma.

Q: Which of the following is NOT a typical effect of hypoparathyroidism on bones?

Brown tumors. Hypoparathyroidism typically does not lead to direct **bone resorption** or the formation of **bone lesions** like brown tumors. The condition results in low serum calcium, but the skeletal effects are not characterized by any of the changes noted in the other options. *Subperiosteal Resorption of Bone* - This is commonly seen in **hyperparathyroidism**, where increased osteoclastic activity leads to bone resorption [1]. Parathyroid hormone (PTH) acts on the skeleton to increase osteoclastic bone resorption; thus, in hypoparathyroidism, there is **decreased bone turnover** with no subperiosteal resorption occurring [1]. *Brown tumours* - Brown tumors are associated with **hyperparathyroidism** due to osteitis fibrosa cystica, characterized by **osteoclastic resorption** [1]. Prolonged exposure of bone to high levels of PTH is associated with these changes, which do not occur in hypoparathyroidism [1]. *Multiple Cysts in Bone* - Multiple bone cysts often represent conditions such as **osteitis fibrosa cystica** in **hyperparathyroidism** or other osteolytic lesions [2]. Hypoparathyroidism primarily leads to a reduction in bone remodeling without promoting cyst formation.

Q: A 65 year old female presents with a swelling in the neck diagnosed as a solitary thyroid nodule. The patient is investigated and a scan shows increased uptake of iodine. Serum T3 and T4 are elevated . Most probabe diagnosis is

Solitary Toxic Adenoma. A **solitary toxic adenoma** is a single thyroid nodule that autonomously produces thyroid hormones, leading to **hyperthyroidism**. The increased iodine uptake on scan reflects its hyperfunctional state, and elevated **T3/T4** confirms hyperthyroidism. [2] - The combination of a **solitary nodule**, **increased iodine uptake**, and **elevated thyroid hormone levels** is pathognomonic for a solitary toxic adenoma. [2] *Benign Thyroid Nodule* - A **benign thyroid nodule** without hyperfunction would typically show **normal or decreased iodine uptake** and **normal T3/T4** levels. [2] - While benign, such a nodule alone does not explain the **elevated T3/T4** or **increased iodine uptake**. *Follicular Carcinoma* - **Follicular carcinoma** is a type of thyroid cancer that typically presents as a **cold nodule** (decreased iodine uptake) and is usually **non-functional**, meaning it does not cause hyperthyroidism with elevated T3/T4. [2] - The presence of **increased iodine uptake** and **hyperthyroidism** makes follicular carcinoma highly unlikely. *Toxic Multinodular Goiter* - A **toxic multinodular goiter** involves **multiple nodules**, not a solitary one, that are autonomously functional and cause hyperthyroidism. [1] - While it causes **hyperthyroidism** and **increased iodine uptake**, the key differentiating factor here is the presentation as a **solitary nodule**.

Q: In a patient with hypoglycemia, what is the appropriate dose adjustment of insulin?

Decrease insulin dosage. ***Decrease insulin dosage*** - Hypoglycemia indicates that the current insulin dose is too high, causing blood glucose levels to drop excessively [1]. - Reducing the insulin dosage helps prevent future episodes of low blood sugar by allowing blood glucose to remain within a healthier range [1]. *Increase insulin dosage* - Increasing insulin would further lower blood glucose, exacerbating the **hypoglycemia** and potentially leading to a more severe and dangerous state. - This action is appropriate for **hyperglycemia**, not hypoglycemia. *Maintain current insulin dosage* - Maintaining the current dose would not address the problem, as it has already proven to be too much for the patient, causing the **hypoglycemic episodes** [1]. - This approach would leave the patient at continued risk for recurrent hypoglycemia. *Add a different medication* - While other medications might be used in diabetes management, adding a new one without adjusting the existing insulin dose could further complicate blood glucose control. - The immediate and most direct action for **hypoglycemia** caused by insulin is to adjust the insulin itself [1].

Question 1

A 55-year-old postmenopausal woman presents with chronic low backache of 6 months duration. She has no history of trauma. What is the most likely diagnosis?

Accepted Answer

Osteoporosis

Answer

Hurler's syndrome

Answer

Paget’s disease

Answer

Renal osteodystrophy

Question 2

A 32-year-old woman complains of amenorrhea since the delivery of a baby 15 months previously, despite the fact that she did not breastfeed her baby. The delivery was complicated by excessive hemorrhage that required a transfusion of 2.5 liters of blood. She has also been fatigued and has gained an additional 4.5Kg since the baby was born. Laboratory data show the following: Serum LH < 1 IU/L (normal, 4-24 IU/L) Serum estradiol 5 pg/mL (normal, 20 - 100 pg/mL) Serum TSH 0.1 mU/L (normal, 0.5 - 5 mU/L) Serum GH 3 ng/mL (normal, < 5 ng/mL) Serum ACTH 28 pg/mL (normal, 10 - 50 pg/mL) Serum prolactin 2 ng/mL (normal, < 20 ng/mL). Injection of 500 μg of TRH failed to produce the expected rise in both serum TSH and prolactin. Which of the following diagnoses most likely explains the findings in this patient?

Accepted Answer

Hypopituitarism due to Sheehan's syndrome

Answer

Pituitary apoplexy

Answer

Isolated gonadotropin deficiency

Answer

Hashimoto's thyroiditis

Answer

Primary amenorrhea

Question 3

Which one of the following statements about Graves' disease is FALSE?

Accepted Answer

Common in male

Answer

Referred to as toxic diffuse goiter

Answer

Results in hyperthyroidism

Answer

Autoimmune disorder

Question 4

Calcitonin levels increased in

Accepted Answer

Medullary thyroid carcinoma

Answer

Hypoparathyroidism

Answer

Cushing Syndrome

Answer

Hyperparathyroidism

Question 5

In which condition is Chvostek's sign typically observed?

Accepted Answer

Hypoparathyroidism

Answer

Hypercalcemia

Answer

Insulinoma

Answer

Diabetes mellitus

Question 6

Which of the following is NOT typically associated with Kallmann's syndrome?

Accepted Answer

Excess stimulation of the HPO axis

Answer

Hypogonadotropic hypogonadism

Answer

Anosmia

Answer

Amenorrhea

Question 7

Thyroid nodule in a 65 year old male who is clinically euthyroid is most likely to be

Accepted Answer

Follicular adenoma

Answer

Multinodular goiter

Answer

Thyroid cyst

Answer

Follicular carcinoma

Question 8

Which of the following is NOT a typical effect of hypoparathyroidism on bones?

Accepted Answer

Brown tumors

Answer

Osteosclerosis

Answer

Multiple bone cysts

Answer

None of the above

Question 9

A 65 year old female presents with a swelling in the neck diagnosed as a solitary thyroid nodule. The patient is investigated and a scan shows increased uptake of iodine. Serum T3 and T4 are elevated . Most probabe diagnosis is

Accepted Answer

Solitary Toxic Adenoma

Answer

Benign Thyroid Nodule

Answer

Follicular Carcinoma

Answer

Toxic Multinodular Goiter

Question 10

In a patient with hypoglycemia, what is the appropriate dose adjustment of insulin?

Accepted Answer

Decrease insulin dosage

Answer

Increase insulin dosage

Answer

Maintain current insulin dosage

Answer

Add a different medication

Endocrinology — MCQs

Endocrinology — MCQs

On this page

Practice by Chapter

Want unlimited practice?