Adrenal Medullary Disorders — MCQs
A 3-year-old boy is found to have spontaneous bursts of non-rhythmic conjugate eye movements in various directions, as well as hypotonia and myoclonus. Physical examination also reveals an abdominal mass. A CT scan shows a mass in the adrenal gland. Which of the following statements is false regarding the patient's condition?
In a patient diagnosed with pheochromocytoma, what is the appropriate preoperative pharmacological management to control hypertension before surgery?
Which of the following is best for diagnosis of pheochromocytoma?
Which of the following is a classic feature of pheochromocytoma?
Investigation of choice in pheochromocytoma is:
Opsoclonus-myoclonus syndrome is seen in -
Which of the following is false about pheochromocytoma?
The following is a histopathological image of thyroid pathology. What is the diagnosis?
What is the most common thyroid tumor associated with multiple endocrine neoplasia (MEN)?
What is the most common carcinoma of the thyroid?
Adrenal Medullary Disorders Indian Medical PG Practice Questions and MCQs
Question 1: A 3-year-old boy is found to have spontaneous bursts of non-rhythmic conjugate eye movements in various directions, as well as hypotonia and myoclonus. Physical examination also reveals an abdominal mass. A CT scan shows a mass in the adrenal gland. Which of the following statements is false regarding the patient's condition?
- A. Immunohistochemical detection of chromogranin is not useful for diagnosis. (Correct Answer)
- B. 70-80% of tumors are associated with elevated production of catecholamines.
- C. Rearrangement or deletion of short arm of chromosome 1 is seen in 25-35% of cases.
- D. The most common site of tumor is adrenal medulla.
Explanation: ***Immunohistochemical detection of chromogranin is not useful for diagnosis.*** - This statement is **false** because **neuroblastoma** cells, which originate from neural crest cells, commonly express **chromogranin A** and C, along with other neuroendocrine markers like **synaptophysin** and **neuron-specific enolase (NSE)** [1]. - **Immunohistochemical staining** for chromogranin is thus a **useful diagnostic tool** to confirm the neuroendocrine differentiation of the tumor [1]. *The most common site of tumor is adrenal medulla.* - This statement is **true**. Approximately **50% of neuroblastomas** originate in the **adrenal glands**, specifically the adrenal medulla, because it is derived from neural crest cells, the precursor cells for neuroblastoma [1]. - Other common sites include the paraspinal ganglia, such as the posterior mediastinum, pelvis, and neck. *70-80% of tumors are associated with elevated production of catecholamines.* - This statement is **true**. Neuroblastoma cells often retain the ability to synthesize and secrete **catecholamines** (**epinephrine, norepinephrine, dopamine**) [1]. - Elevated levels of **vanillylmandelic acid (VMA)** and **homovanillic acid (HVA)**, which are the **breakdown products (metabolites) of catecholamines**, are detected in the urine of 70-80% of patients and serve as **important diagnostic and prognostic markers** [1]. *Rearrangement or deletion of short arm of chromosome 1 is seen in 25-35% of cases.* - This statement is **true**. **Deletion** or **rearrangement** of the **short arm of chromosome 1 (1p36)** is a common **cytogenetic abnormality** found in 25-35% of neuroblastomas. - This genetic alteration is often associated with **poor prognosis** and more aggressive disease behavior. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 483-487.
Question 2: In a patient diagnosed with pheochromocytoma, what is the appropriate preoperative pharmacological management to control hypertension before surgery?
- A. Phenoxybenzamine and propranolol (Correct Answer)
- B. Propranolol
- C. Nitroglycerine
- D. Phentolamine
Explanation: ***Phenoxybenzamine and propranolol*** - **Phenoxybenzamine** (an **irreversible** non-selective **alpha-blocker**) is initiated first to prevent hypertensive crises during surgery by blocking the effects of catecholamines on blood vessels. - **Propranolol** (a **beta-blocker**) is added after adequate alpha-blockade to control **tachycardia** and arrhythmias, as blocking only alpha-receptors can lead to unopposed beta-adrenergic stimulation. *Phentolamine (short-acting alpha blocker)* - While **phentolamine** is an alpha-blocker, it is typically used for **intraoperative management** of hypertensive crises or for short-term control, not as the primary preoperative preparation. - It is a **reversible** blocker and does not provide the sustained, robust alpha-blockade required for safe preoperative management of pheochromocytoma. *Propranolol (beta-blocker)* - **Beta-blockers** alone should **never be started first** in pheochromocytoma because blocking beta-2 receptors (which mediate vasodilation) in the presence of high circulating catecholamines can lead to **unopposed alpha-adrenergic vasoconstriction**, causing a dangerous hypertensive crisis. - It is only added after adequate alpha-blockade has been achieved to manage **tachycardia**. *Nitroglycerine (vasodilator)* - **Nitroglycerine** is primarily a **venodilator** and is used to relieve angina or manage acute hypertensive emergencies, not for the chronic preoperative management of pheochromocytoma. - It does not address the underlying pathophysiology of excessive catecholamine release and can lead to reflex **tachycardia**.
Question 3: Which of the following is best for diagnosis of pheochromocytoma?
- A. 24-hour Urinary Hydroxy indole acetic acid
- B. 24-hour urinary Vanillyl Mandelic acid
- C. 24-hour Urinary Hydroxy tryptamine
- D. 24-hour urinary Fractionated Metanephrine (Correct Answer)
Explanation: ***24-hour urinary Fractionated Metanephrine*** - This test measures the **metabolites of catecholamines** (epinephrine and norepinephrine), which are continuously produced by pheochromocytomas [1]. - As metanephrines are released continuously rather than episodically, their measurement in a 24-hour urine collection provides the **highest sensitivity and specificity** for diagnosing pheochromocytoma. *24-hour Urinary Hydroxy indole acetic acid* - This is a metabolite of **serotonin**, which is relevant to conditions like **carcinoid syndrome**, not pheochromocytoma. - Elevated levels would indicate a serotonin-producing tumor, not a catecholamine-producing tumor. *24-hour urinary Vanillyl Mandelic acid* - While VMA is a metabolite of both epinephrine and norepinephrine, it is a less specific and sensitive marker than fractionated metanephrines for pheochromocytoma. - Its measurement can be affected by various medications and dietary factors, leading to a higher rate of false positives and negatives compared to metanephrines. *24-hour Urinary Hydroxy tryptamine* - This refers to **serotonin**, which is not directly relevant to the diagnosis of pheochromocytoma. - Elevated levels would point towards conditions involving serotonin metabolism, such as carcinoid tumors.
Question 4: Which of the following is a classic feature of pheochromocytoma?
- A. Headache (Correct Answer)
- B. Hyperkalemia
- C. Bradycardia
- D. Hypoglycemia
Explanation: ***Headache*** - Severe, pounding **headaches** are a classic symptom due to the paroxysmal release of **catecholamines** causing extreme hypertension. - This symptom is often one of the "P's" associated with pheochromocytoma: palpitations, perspiration, pallor, and paroxysmal hypertension. *Hyperkalemia* - **Hyperkalemia** is not typically associated with pheochromocytoma; rather, the excessive catecholamine release can sometimes cause stress-induced hypokalemia due to increased intracellular potassium shift. - The primary electrolyte imbalance to watch for is related to severe hypertension complications. *Bradycardia* - **Bradycardia** is generally not a feature of pheochromocytoma; instead, patients frequently experience **tachycardia** and **palpitations** due to the stimulatory effects of catecholamines on the heart. - The sympathetic nervous system activation leads to an increased heart rate. *Hypoglycemia* - **Hypoglycemia** is uncommon in pheochromocytoma; the excess catecholamines typically lead to **hyperglycemia** by promoting glycogenolysis and gluconeogenesis, and inhibiting insulin release. - This elevation in blood sugar can mimic diabetes, sometimes requiring insulin therapy.
Question 5: Investigation of choice in pheochromocytoma is:
- A. CT scan
- B. Urinary catecholamines (Correct Answer)
- C. MIBG scan
- D. MRI Scan
Explanation: ***Urinary catecholamines*** - Measurement of **24-hour urinary fractionated metanephrines and catecholamines** is the initial **biochemical test of choice**. - These biochemical tests are preferred over plasma levels due to the **episodic release** of hormones from a pheochromocytoma, which can lead to high false-negative rates in single plasma measurements. *CT scan* - While a **CT scan** is a crucial **imaging modality** for localizing a pheochromocytoma once the biochemical diagnosis is established [1], it is not the *initial* diagnostic investigation. - Imaging should be performed only after **biochemical confirmation** to avoid unnecessary investigations of incidental adrenal masses [1]. *MIBG scan* - An **MIBG scan** (metaiodobenzylguanidine scan) is a **functional imaging study** used primarily for **localizing metastatic pheochromocytomas** [1] or for cases where CT/MRI is equivocal. - It is not the initial investigation but rather a **secondary imaging test** [1]. *MRI Scan* - **MRI** is an alternative **imaging modality** to CT for localizing pheochromocytomas [1], especially in pregnant women or when radiation exposure is a concern. - Like CT, it serves as a **localization tool** after biochemical confirmation, not the diagnostic test itself.
Question 6: Opsoclonus-myoclonus syndrome is seen in -
- A. Melanoma
- B. Neuroblastoma (Correct Answer)
- C. Retinoblastoma
- D. Nephroblastoma
Explanation: ***Neuroblastoma*** - Opsoclonus-myoclonus syndrome (OMS) is a **rare paraneoplastic neurological syndrome** most commonly associated with **neuroblastoma** in children [1]. - The syndrome is characterized by **opsoclonus** (chaotic, multidirectional eye movements), **myoclonus** (brief, involuntary muscle jerks), and ataxia. *Melanoma* - Melanoma is rarely associated with OMS; however, it can be linked to other paraneoplastic syndromes like **Lambert-Eaton myasthenic syndrome** or **cerebellar degeneration** [2]. - Its primary neurological manifestations usually involve brain metastases rather than paraneoplastic syndromes. *Retinoblastoma* - Retinoblastoma is an intraocular malignancy of childhood that typically does not cause paraneoplastic syndromes like OMS. - Its neurological complications are usually related to **direct tumor extension** or leptomeningeal metastasis. *Nephroblastoma* - Nephroblastoma, also known as **Wilms' tumor**, is a kidney cancer in children. - It is not typically associated with paraneoplastic neurological syndromes like OMS; its paraneoplastic manifestations might include syndromes like **hypercalcemia** due to ectopic hormone production.
Question 7: Which of the following is false about pheochromocytoma?
- A. Surgery is the treatment of choice
- B. VMA (vanillylmandelic acid) is a diagnostic test
- C. Propranolol is the preferred drug for hypertension control (Correct Answer)
- D. Catecholamines are a diagnostic test
- E. Most pheochromocytomas are benign
Explanation: ***Propranolol is the preferred drug for hypertension control*** - Propranolol, a **beta-blocker**, is generally contraindicated as monotherapy in pheochromocytoma because blocking beta-receptors unopposed can lead to a **hypertensive crisis** due to unopposed alpha-adrenergic vasoconstriction. - **Alpha-blockers** (e.g., phenoxybenzamine) are the first-line agents for hypertension control, followed by beta-blockers once adequate alpha-blockade is established. *Surgery is the treatment of choice* - **Surgical resection** of the tumor is indeed the definitive treatment for pheochromocytoma once the patient has been appropriately prepared with alpha-blockade. - This approach aims to remove the source of excessive catecholamine production and resolve the associated symptoms. *VMA (vanillylmandelic acid) is a diagnostic test* - **VMA** is a metabolic breakdown product of catecholamines, and its measurement in a **24-hour urine collection** is a long-standing method for diagnosing pheochromocytoma. - Elevated VMA levels indicate overproduction of catecholamines, which is characteristic of the tumor. *Catecholamines are a diagnostic test* - Measuring **plasma free metanephrines** and **24-hour urinary fractionated metanephrines** (which are methylated metabolites of catecholamines) are highly sensitive and specific diagnostic tests for pheochromocytoma. - Elevated levels confirm the excessive secretion of these hormones by the tumor. *Most pheochromocytomas are benign* - Approximately **90% of pheochromocytomas are benign**, with only about 10% being malignant. - The **"rule of 10s"** is a helpful mnemonic: 10% bilateral, 10% extra-adrenal, 10% malignant, 10% familial, and 10% occur in children.
Question 8: The following is a histopathological image of thyroid pathology. What is the diagnosis?
- A. Papillary carcinoma of thyroid
- B. Medullary carcinoma of thyroid (Correct Answer)
- C. Follicular carcinoma of thyroid
- D. Anaplastic carcinoma of thyroid
Explanation: ***Medullary carcinoma of thyroid*** - This image shows sheets and nests of **polygonal to spindle-shaped cells**, which are characteristic of medullary thyroid carcinoma, especially when mixed with an **amyloid stroma** (seen as amorphous eosinophilic material) [2]. - The presence of **neuroendocrine features** and the production of **calcitonin** are hallmarks of these C-cell tumors [1], [2]. *Papillary carcinoma of thyroid* - Characterized by **papillary architecture**, **ground-glass (Orphan Annie eye) nuclei**, nuclear grooves, and intranuclear cytoplasmic inclusions. - These features are not prominently seen in the provided image. *Follicular carcinoma of thyroid* - Defined by an invasive growth pattern of **well-differentiated follicular cells** forming follicles, with either capsular or vascular invasion [2]. - The image does not show classic follicular architectural patterns or clear evidence of invasion in the absence of a capsule. *Anaplastic carcinoma of thyroid* - This is a highly aggressive and undifferentiated tumor with **marked pleomorphism**, bizarre giant cells, and high mitotic activity [2]. - While there is some pleomorphism, the overall pattern and cellular morphology in the image are more consistent with medullary carcinoma than the extreme anaplasia. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1102-1103. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 428-431.
Question 9: What is the most common thyroid tumor associated with multiple endocrine neoplasia (MEN)?
- A. Follicular
- B. Papillary
- C. Anaplastic
- D. Medullary (Correct Answer)
Explanation: ***Medullary*** - The **commonest thyroid tumor** in Multiple Endocrine Neoplasia (MEN) type 2 is medullary thyroid carcinoma, associated with **calcitonin production** [1]. - It arises from **C cells (parafollicular cells)** and is linked to **RET oncogene mutations** in MEN syndromes [1]. *Papillary* - Papillary thyroid carcinoma is the **most common thyroid cancer overall**, but not specifically associated with MEN syndromes. - It typically presents with **lymphatic spread**, whereas medullary carcinoma has a different genetic association. *Follicular* - Follicular thyroid carcinoma is less common in MEN and usually occurs sporadically. - It primarily arises from **follicular cells** and involves a different mechanism than medullary carcinoma. *Anaplastic* - Anaplastic thyroid carcinoma is a rare and highly aggressive form, not commonly associated with MEN. - It usually arises from **differentiated thyroid cancers** and presents in older patients, which does not align with MEN's typical presentations. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1102-1103.
Question 10: What is the most common carcinoma of the thyroid?
- A. Papillary thyroid carcinoma (Correct Answer)
- B. Follicular thyroid carcinoma
- C. Hurthle cell carcinoma
- D. Medullary thyroid carcinoma
Explanation: ***Papillary thyroid carcinoma*** - This is the **most common type** of thyroid cancer, accounting for approximately 80-85% of all thyroid malignancies [1], [2]. - It typically has an **excellent prognosis** due to its relatively slow growth and tendency to metastasize through lymphatics rather than hematogenously [2]. *Follicular thyroid carcinoma* - This is the **second most common** type of thyroid cancer, comprising about 10-15% of cases [2]. - It tends to metastasize **hematogenously** to distant sites like bones and lungs, which is a key differentiator from papillary carcinoma [2]. *Hurthle cell carcinoma* - Also known as **oxyphilic follicular carcinoma**, this is considered a variant of follicular carcinoma, though sometimes classified separately. - It is **less common** than papillary or follicular carcinoma and is characterized by cells with abundant, eosinophilic, granular cytoplasm. *Medullary thyroid carcinoma* - This is a neuroendocrine tumor arising from the **parafollicular C cells** of the thyroid, which produce **calcitonin** [3], [4]. - It accounts for only about 3-5% of thyroid cancers and can be sporadic or hereditary, often associated with **MEN 2 syndromes** [3], [4]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1098-1099. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 428-430. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 428-429. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1102-1103.
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