Multiple Endocrine Neoplasia — MCQs
What is the most common thyroid tumor associated with multiple endocrine neoplasia (MEN)?
Which of the following is not seen in MEN 2B syndrome?
A patient presents with headaches, palpitations, hypertension, and urine VMA positivity. The biopsy findings are shown in the image. Which of the following statements is correct?
Which type of thyroid cancer is associated with primary hyperparathyroidism and phaeochromocytoma?
All of the following are seen in MEN 2B except which of the following?
Submucosal neuroma is associated with
A young patient presented with hypertension and a 24-hour urinary metanephrine level of 1.4 mg, the most likely causes are -
Which of the following statements about pheochromocytoma is true?
Nelson syndrome is associated with:
A 45 -year-old lady presents with complaints of fatigue, muscle weakness along with bilateral multiple renal calculi which were picked up on a routine ultrasound. Further workup revealed serum calcium levels of 11.4 mg %. What is the next best investigation required to arrive at a diagnosis?
Multiple Endocrine Neoplasia Indian Medical PG Practice Questions and MCQs
Question 1: 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 2: Which of the following is not seen in MEN 2B syndrome?
- A. Mucosal neuroma
- B. Marfanoid habitus
- C. Parathyroid adenoma (Correct Answer)
- D. Megacolon
Explanation: ***Parathyroid adenoma*** - **Parathyroid adenomas**, leading to hyperparathyroidism, are characteristic of **MEN 2A syndrome**, not MEN 2B [1]. - While both MEN 2A and 2B involve mutations in the **RET proto-oncogene**, the specific clinical manifestations differ significantly. *Megacolon* - **Megacolon** (due to intestinal ganglioneuromatosis) is a recognized feature of **MEN 2B syndrome**. - This condition involves abnormal nerve ganglion cells in the intestine, leading to motility issues. *Mucosal neuroma* - **Mucosal neuromas** on the tongue, lips, and eyelids are a hallmark clinical sign of **MEN 2B syndrome**. - These benign growths are often one of the earliest and most recognizable features. *Marfanoid habitus* - **Marfanoid habitus**, characterized by a tall, slender build with long limbs and arachnodactyly, is a common physical finding in **MEN 2B syndrome**. - This connective tissue abnormality helps distinguish MEN 2B from other MEN syndromes.
Question 3: A patient presents with headaches, palpitations, hypertension, and urine VMA positivity. The biopsy findings are shown in the image. Which of the following statements is correct?
- A. Mostly malignant
- B. Mostly in children
- C. Mostly bilateral
- D. Associated with MEN 2A (Correct Answer)
Explanation: ***Associated with MEN 2A*** - The clinical presentation (headaches, palpitations, hypertension) and positive **urine VMA (vanillylmandelic acid)** strongly suggest a **pheochromocytoma**. - Pheochromocytomas are tumors of the adrenal medulla that secrete catecholamines and are frequently associated with **Multiple Endocrine Neoplasia Type 2A (MEN 2A)**, along with medullary thyroid carcinoma and primary hyperparathyroidism. *Mostly malignant* - Pheochromocytomas are generally benign, with approximately **10% being malignant** ("rule of 10s"). - Malignancy is difficult to predict based on histology alone and is usually defined by the presence of **metastases**. *Mostly in children* - While pheochromocytomas can occur at any age, they are **more common in adults**, typically between 30 and 50 years old. - When they do occur in children, they are more often bilateral, extra-adrenal, or associated with genetic syndromes. *Mostly bilateral* - The majority of pheochromocytomas (approximately **90%**) are **unilateral**. - Bilateral pheochromocytomas are often seen in genetic syndromes such as **MEN 2**, von Hippel-Lindau disease, and neurofibromatosis type 1.
Question 4: Which type of thyroid cancer is associated with primary hyperparathyroidism and phaeochromocytoma?
- A. Medullary carcinoma of the thyroid (Correct Answer)
- B. Papillary carcinoma of the thyroid
- C. Anaplastic carcinoma of the thyroid
- D. Follicular carcinoma of the thyroid
Explanation: ***Medullary carcinoma of the thyroid*** - Associated with **multiple endocrine neoplasia (MEN) syndrome type 2**, which includes primary hyperparathyroidism and phaeochromocytoma [1]. - Medullary carcinoma arises from **C cells** (parafollicular cells) and is linked with **elevated calcitonin** levels. *Papillary carcinoma of the thyroid* - The most common type of thyroid cancer, but **not associated** with MEN syndromes. - Typically presents as a solitary **nodule** and is linked with **radiation exposure** rather than endocrine syndromes. *Anaplastic carcinoma of the thyroid* - A highly aggressive and undifferentiated form of thyroid cancer, often associated with **poor prognosis**. - Usually arises in older adults and does not have associations with **hyperparathyroidism** or phaeochromocytoma. *Follicular carcinoma of the thyroid* - Characterized by **thyroid follicle formation** and can be associated with **iodine deficiency**, but not with MEN syndromes. - It usually presents as a **solitary thyroid nodule** and lacks connection with **primary hyperparathyroidism**.
Question 5: All of the following are seen in MEN 2B except which of the following?
- A. Neuromas
- B. Pheochromocytoma
- C. Medullary carcinoma thyroid
- D. Hyperparathyroidism (Correct Answer)
Explanation: ***Hyperparathyroidism*** - **Hyperparathyroidism** is a characteristic feature of **MEN 1** and **MEN 2A**, but it is typically **absent in MEN 2B**. - MEN 2B is primarily associated with **RET gene mutations** that do not commonly lead to parathyroid gland hyperplasia or adenomas. *Neuromas* - **Mucosal neuromas**, particularly in the lips, tongue, and gastrointestinal tract, are a **hallmark feature of MEN 2B**. - These benign tumors are a key diagnostic clue for this syndrome. *Medullary carcinoma thyroid* - **Medullary thyroid carcinoma (MTC)** is a **nearly universal and aggressive component of MEN 2B**, arising from parafollicular C-cells. - It is often the presenting feature and requires early detection and thyroidectomy due to its high metastatic potential. *Pheochromocytoma* - **Pheochromocytoma**, a tumor of the adrenal medulla, occurs in approximately 50-70% of individuals with **MEN 2B**. - It can cause severe hypertension and is an important component of the syndrome that needs to be screened for due to its potential for life-threatening hypertensive crises.
Question 6: Submucosal neuroma is associated with
- A. MEN 2 A
- B. MEN 2B (Correct Answer)
- C. MEN 1
- D. None of the options
Explanation: ***MEN 2B (Multiple Endocrine Neoplasia Type 2B)*** - **Submucosal neuromas** are a distinctive feature of MEN 2B, specifically noticeble as mucosal neuromas on the lips, tongue, and gastrointestinal tract. - This syndrome is characterized by the presence of **medullary thyroid carcinoma**, **pheochromocytoma**, and mucocutaneous neuromas, without hyperparathyroidism. *MEN 2A (Multiple Endocrine Neoplasia Type 2A)* - MEN 2A is characterized by **medullary thyroid carcinoma**, **pheochromocytoma**, and **primary hyperparathyroidism**. - It does not typically feature extensive **submucosal neuromas** as a primary diagnostic criterion. *MEN 1 (Multiple Endocrine Neoplasia Type 1)* - MEN 1 involves tumors of the **parathyroid glands**, **anterior pituitary**, and **pancreatic islet cells** (the '3 Ps'). - **Submucosal neuromas** are not a component of the MEN 1 syndrome. *None of the options* - This option is incorrect because **submucosal neuromas** are a characteristic finding in MEN 2B.
Question 7: A young patient presented with hypertension and a 24-hour urinary metanephrine level of 1.4 mg, the most likely causes are -
- A. Grave's disease
- B. Pseudohypoparathyroidism
- C. Medullary carcinoma thyroid
- D. VonHippelLindau syndrome (Correct Answer)
Explanation: ***Von Hippel-Lindau syndrome*** - This syndrome is a **hereditary condition** predisposing individuals to various tumors, including **pheochromocytomas**, which cause elevated **metanephrines** and hypertension. - The combination of **hypertension** in a young patient and an elevated **24-hour urinary metanephrine level** (indicating excessive catecholamine production) strongly suggests a pheochromocytoma, which is frequently associated with Von Hippel-Lindau syndrome. *Medullary carcinoma thyroid* - This cancer is associated with **MEN 2 syndromes** and produces **calcitonin**, leading to hypocalcemia, but not typically elevated metanephrines or hypertension directly from the thyroid. - While it can be associated with **pheochromocytoma** (as part of MEN 2), it is not the direct cause of the elevated metanephrines. *Grave's disease* - **Grave's disease** is an autoimmune disorder causing **hyperthyroidism**, characterized by symptoms like goiter, exophthalmos, and weight loss. - While it can cause hypertension due to increased cardiac output, it does not lead to elevated **urinary metanephrine levels**, which are specific to catecholamine excess. *Pseudohypoparathyroidism* - This is a genetic disorder characterized by **target organ resistance to parathyroid hormone (PTH)**, leading to hypocalcemia and hyperphosphatemia [1]. - It does not cause hypertension or elevated **urinary metanephrine levels**.
Question 8: Which of the following statements about pheochromocytoma is true?
- A. Arises from chromaffin cells of adrenal medulla (Correct Answer)
- B. Bilateral in 20% of all cases
- C. Hypotension rules out pheochromocytoma
- D. Almost always a malignant tumor
Explanation: ***Arises from chromaffin cells of adrenal medulla*** - **Pheochromocytomas** are rare neuroendocrine tumors that develop from **chromaffin cells** found in the adrenal medulla. - These cells are responsible for synthesizing and secreting **catecholamines**, explaining the characteristic symptoms of pheochromocytoma. *Bilateral in 20% of all cases* - While pheochromocytomas can be bilateral, this occurs in about **10% of cases**, mostly associated with genetic syndromes like **MEN 2**. - A higher percentage of bilaterality is seen in **familial forms** of the disease, but not in all cases. *Hypotension rules out pheochromocytoma* - Although **hypertension** is a hallmark symptom, **hypotension** can occur, particularly **orthostatic hypotension** due to volume depletion and impaired vasoconstriction. - Rarely, **pheochromocytoma crisis** can present with **shock** due to massive catecholamine release and subsequent myocardial dysfunction or vasoplegia. *Almost always a malignant tumor* - Most pheochromocytomas are **benign**; only about **10-15%** are malignant. - Malignancy is suggested by the presence of **metastatic disease**, as histology alone cannot reliably differentiate between benign and malignant forms.
Question 9: Nelson syndrome is associated with:
- A. Subarachnoid hemorrhage
- B. Prophylactic craniospinal irradiation
- C. Bilateral adrenalectomy (Correct Answer)
- D. BRCA2 mutation
Explanation: ***Bilateral adrenalectomy*** - **Nelson syndrome** develops in a subset of patients with Cushing's disease after **bilateral adrenalectomy**. [1] - It is caused by the loss of negative feedback from adrenal cortisol on the pituitary, leading to continued growth of an existing **ACTH-secreting pituitary adenoma**. *Prophylactic craniospinal irradiation* - **Craniospinal irradiation** is a radiotherapy technique used to treat disseminated cancers like medulloblastoma but is not directly associated with the etiology of Nelson syndrome. - While pituitary tumors can be treated with radiotherapy, this is typically given once a tumor has caused symptoms, not prophylactically in this context. *Subarachnoid hemorrhage* - **Subarachnoid hemorrhage** is bleeding into the space between the brain and the surrounding membrane, often caused by ruptured **aneurysms** or **trauma**. - It is a neurological emergency unrelated to the development of Nelson syndrome. *BRCA2 mutation* - **BRCA2 mutations** are strongly associated with an increased risk of developing various cancers, most notably **breast** and **ovarian cancer**. - This genetic mutation is not linked to the pathogenesis of Nelson syndrome, which is an endocrine complication following surgery.
Question 10: A 45 -year-old lady presents with complaints of fatigue, muscle weakness along with bilateral multiple renal calculi which were picked up on a routine ultrasound. Further workup revealed serum calcium levels of 11.4 mg %. What is the next best investigation required to arrive at a diagnosis?
- A. MRI neck
- B. CECT head and neck
- C. NCCT head and neck
- D. Sestamibi scan (Correct Answer)
Explanation: ***Sestamibi scan*** - A **Sestamibi scan** is the preferred imaging modality for localizing a parathyroid adenoma [1], which is the most common cause of **primary hyperparathyroidism**. - **Primary hyperparathyroidism** often presents with **hypercalcemia** (serum calcium 11.4 mg%), **renal calculi** [1], fatigue, and muscle weakness, as described in the patient. *MRI neck* - While an MRI can visualize neck structures, it is **less specific** for identifying small parathyroid adenomas compared to a Sestamibi scan. - It might be used in cases where other imaging modalities are inconclusive but is not the initial best investigation. *CECT head and neck* - **CECT (Contrast-Enhanced Computed Tomography)** is not the primary choiceto locate parathyroid adenomas as it involves radiation and intravenous contrast, which may not be necessary. - Parathyroid adenomas can be small and difficult to differentiate from thyroid tissue or lymph nodes on CECT alone. *NCCT head and neck* - **NCCT (Non-Contrast Computed Tomography)** is even less effective than CECT for localizing parathyroid adenomas as it lacks the discriminatory power of contrast enhancement. - It would mainly show bony structures and calcifications, which are not helpful for identifying a glandular adenoma.
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