Neuroendocrine Tumors — MCQs
A 38-year-old female presents to the physician with complaints of excessive thirst and urination for the past 4 weeks. Her appetite has been normal and she has not had diarrhea. Blood chemistry showed mildly elevated glucose and glucagon. Physical examination reveals tenderness in the left upper quadrant and an erythematous necrotizing skin eruption on her legs. Radiographic studies show a tumor in the pancreas. Which of the following cells is responsible for this lesion?
FDG-PET negative tumor is:
MC location of gastrinoma in MEN-1 syndrome?
In a patient diagnosed with pheochromocytoma, what is the appropriate preoperative pharmacological management to control hypertension before surgery?
Which of the following is used in the treatment of well-differentiated thyroid carcinoma?
Which of the following is true regarding carcinoid tumor?
What is the appropriate management for a patient with a carcinoid tumor of the appendix larger than 2 cm?
Statement 1 - A 59-year-old patient presents with flaccid bullae. Histopathology shows a suprabasal acantholytic split. Statement 2 - The row of tombstones appearance is diagnostic of Pemphigus vulgaris.
A 45-year-old develops dysphagia 3 months post thyroidectomy. Most likely cause?
Which of the following is the best indicator of prognosis of soft tissue sarcoma?
Neuroendocrine Tumors Indian Medical PG Practice Questions and MCQs
Question 1: A 38-year-old female presents to the physician with complaints of excessive thirst and urination for the past 4 weeks. Her appetite has been normal and she has not had diarrhea. Blood chemistry showed mildly elevated glucose and glucagon. Physical examination reveals tenderness in the left upper quadrant and an erythematous necrotizing skin eruption on her legs. Radiographic studies show a tumor in the pancreas. Which of the following cells is responsible for this lesion?
- A. Beta cell
- B. Acinar cell
- C. Delta cell
- D. Alpha cell (Correct Answer)
Explanation: ### Alpha cell - The constellation of **excessive thirst and urination (polyuria/polydipsia)**, **mildly elevated glucose**, **elevated glucagon**, **necrolytic migratory erythema (NME)**, and a **pancreatic tumor** is highly characteristic of a **glucagonoma**. [1] - Glucagonomas originate from **pancreatic alpha cells**, which are responsible for glucagon production. [2] ### Beta cell - **Beta cell tumors** (insulinomas) primarily cause **hypoglycemia** due to excessive insulin secretion, which is antithetical to the patient's symptoms of elevated glucose. [2] - While beta cell tumors can be found in the pancreas, they are not associated with necrolytic migratory erythema or glucagon excess. [1] ### Acinar cell - **Acinar cell carcinomas** are exocrine pancreatic tumors that can cause symptoms related to their size and local invasion (e.g., pain, weight loss, jaundice) but are not typically associated with specific hormonal syndromes such as glucagon excess. - They do not cause the characteristic skin rash or metabolic disturbances seen in this patient. ### Delta cell - **Delta cells** produce **somatostatin**, and tumors originating from these cells (somatostatinomas) can cause symptoms like diabetes, steatorrhea, and gallstones. - However, they do not typically present with elevated glucagon or the characteristic necrolytic migratory erythema.
Question 2: FDG-PET negative tumor is:
- A. Typical carcinoid (Correct Answer)
- B. Atypical carcinoid
- C. Small cell carcinoma
- D. Large cell neuroendocrine carcinoma
Explanation: ***Typical carcinoid*** - **Typical carcinoid tumors** generally have a low metabolic rate and thus do not avidly take up **FDG (fluorodeoxyglucose)**, appearing **FDG-PET negative**. - These tumors are characterized by low mitotic activity and lack of necrosis, contributing to their low glucose metabolism. *Atypical carcinoid* - **Atypical carcinoid tumors** have a higher proliferative index and increased metabolic activity compared to typical carcinoids. - They tend to be **FDG-PET positive** due to their higher glucose utilization. *Small cell carcinoma* - **Small cell carcinoma** is a highly aggressive tumor type with rapid proliferation and high metabolic activity. - It is typically **FDG-PET positive**, reflecting its significant glucose uptake. *Large cell neuroendocrine carcinoma* - **Large cell neuroendocrine carcinoma (LCNEC)** is also an aggressive tumor with a high mitotic rate and often exhibits necrosis. - Similar to small cell carcinoma, LCNEC is generally **FDG-PET positive** due to its high metabolic demand.
Question 3: MC location of gastrinoma in MEN-1 syndrome?
- A. Jejunum
- B. Ileum
- C. Duodenum
- D. Pancreas (Correct Answer)
Explanation: ***Pancreas*** - In **Multiple Endocrine Neoplasia type 1 (MEN-1) syndrome**, gastrinomas are most commonly found in the **pancreas**. - While sporadic gastrinomas are frequently duodenal, the **genetic predisposition of MEN-1** shifts the primary location to the pancreas. *Duodenum* - **Sporadic gastrinomas** without MEN-1 syndrome are most frequently located in the **duodenum**, particularly the first and second parts. - However, in the context of **MEN-1**, the pancreas becomes the predominant site for gastrinoma development. *Jejunum* - The jejunum is an **uncommon location** for gastrinomas in both sporadic cases and those associated with MEN-1. - Gastrinomas found in the jejunum are typically **rare** and often associated with more aggressive disease or disseminated metastasis. *Ileum* - The ileum is an **extremely rare site** for gastrinomas. - Gastrinomas developing in the ileum are usually **ectopic** and are not typically the primary location in either sporadic cases or MEN-1 syndrome.
Question 4: 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 5: Which of the following is used in the treatment of well-differentiated thyroid carcinoma?
- A. I131 (Correct Answer)
- B. 99m Tc
- C. 32p
- D. MIBG
Explanation: ***I131*** - **Radioactive iodine (I131)** is specifically absorbed by **well-differentiated thyroid cancer cells** because these cells retain the ability to uptake iodine, unlike other types of cancer cells. - Used for **ablating residual thyroid tissue** after surgery and for treating **metastatic well-differentiated thyroid carcinoma** [1]. *99m Tc* - **Technetium-99m (99m Tc)** is primarily used for **diagnostic imaging** (e.g., thyroid scans, bone scans), not for therapeutic treatment of thyroid cancer. - It has a short half-life and emits gamma rays, making it suitable for imaging but generally not for delivering sustained radiation for therapeutic effect. *32p* - **Phosphorus-32 (32p)** is a beta-emitting radionuclide used in the treatment of certain hematological malignancies, such as **polycythemia vera**, and for palliative treatment of bone metastases. - It is not selectively taken up by thyroid cancer cells and therefore is not used in the treatment of thyroid carcinoma. *MIBG* - **Metaiodobenzylguanidine (MIBG)**, often labeled with I123 (diagnostic) or I131 (therapeutic), is used in the diagnosis and treatment of **neuroendocrine tumors** like **pheochromocytoma** and **neuroblastoma**. - Its uptake mechanism targets cells of neuroectodermal origin, which is distinct from the iodine uptake mechanism of thyroid cells.
Question 6: Which of the following is true regarding carcinoid tumor?
- A. Associated with serotonin production
- B. Potentially malignant tumor
- C. Neuroendocrine tumor (Correct Answer)
- D. Most common site is lung
Explanation: ### Most common site is lung - Carcinoid tumors are more commonly found in the **gastrointestinal tract**, specifically the appendix and ileum, rather than the lungs [1]. - This statement is false as they can occur in the lungs but are not the most common site overall. ### Potentially malignant tumor - Carcinoid tumors can be classified as **malignant,** especially if they show aggressive behavior or metastasis. - Many carcinoid tumors, particularly those in the gastrointestinal tract, can be **non-functional** and less aggressive [1]. ### Neuroendocrine tumor - Carcinoid tumors are indeed a type of **neuroendocrine tumor**, arising from **neuroendocrine cells**. - This classification emphasizes their origin and potential for secretion of hormones like **serotonin**. ### Associated with serotonin production - Many carcinoid tumors produce **serotonin**, leading to symptoms like **carcinoid syndrome** when they metastasize, particularly to the liver [1]. - This statement is true, indicating their involvement in neuroendocrine secretions.
Question 7: What is the appropriate management for a patient with a carcinoid tumor of the appendix larger than 2 cm?
- A. Right hemicolectomy (Correct Answer)
- B. Appendicectomy
- C. Appendicectomy + abdominal CT scan
- D. Appendicectomy + 24 hrs urinary HIAA
Explanation: ***Right hemicolectomy*** - Carcinoid tumors of the appendix larger than **2 cm** are considered at high risk for **lymph node metastasis** and recurrence. - A **right hemicolectomy** provides adequate margins and allows for lymph node dissection, which is essential for staging and definitive treatment in such cases. *Appendicectomy* - An **appendicectomy** alone is typically sufficient for carcinoid tumors of the appendix that are **less than 1 cm** and localized to the tip. - For larger tumors, appendicectomy carries an unacceptably high risk of **incomplete resection** and metastatic disease. *Appendicectomy + abdominal CT scan* - While an **abdominal CT scan** is useful for assessing local spread and distant metastases, it does not address the need for a more extensive surgical resection for a **large primary tumor**. - A simple **appendicectomy** in this scenario would be inadequate as definitive treatment. *Appendicectomy + 24 hrs urinary HIAA* - **24-hour urinary 5-hydroxyindoleacetic acid (5-HIAA)** is a biomarker used to detect and monitor **carcinoid syndrome**, which occurs in a minority of patients with carcinoid tumors. - Measuring 5-HIAA is primarily for assessing systemic symptoms rather than determining the primary surgical management of the **tumor size**.
Question 8: Statement 1 - A 59-year-old patient presents with flaccid bullae. Histopathology shows a suprabasal acantholytic split. Statement 2 - The row of tombstones appearance is diagnostic of Pemphigus vulgaris.
- A. Statements 1 & 2 are correct, 2 is not explaining 1 (Correct Answer)
- B. Statements 1 and 2 are correct and 2 is the correct explanation for 1
- C. Statements 1 and 2 are incorrect
- D. Statement 1 is incorrect
Explanation: ***Correct: Statements 1 & 2 are correct, 2 is not explaining 1*** **Analysis of Statement 1:** - A 59-year-old patient with **flaccid bullae** and **suprabasal acantholytic split** on histopathology is the classic presentation of **Pemphigus vulgaris** - The flaccid (easily ruptured) nature of bullae distinguishes it from tense bullae seen in bullous pemphigoid - The suprabasal location of the split (just above the basal layer) with acantholysis (loss of cell-to-cell adhesion) is pathognomonic - **Statement 1 is CORRECT** ✓ **Analysis of Statement 2:** - The **"row of tombstones" or "tombstone appearance"** is indeed a diagnostic histopathological feature of Pemphigus vulgaris - This appearance results from basal keratinocytes remaining attached to the basement membrane while suprabasal cells separate due to acantholysis - The intact basal cells standing upright resemble a row of tombstones - **Statement 2 is CORRECT** ✓ **Does Statement 2 explain Statement 1?** - Statement 2 describes a **histopathological appearance** (tombstone pattern) that is a **consequence** of the suprabasal split - However, it does NOT explain the **underlying cause** of the flaccid bullae or the suprabasal split - The true explanation involves **IgG autoantibodies against desmoglein 3 (and desmoglein 1)**, which attack intercellular adhesion structures (desmosomes), causing **acantholysis** - Therefore, **Statement 2 does NOT explain Statement 1** ✗ *Incorrect: Statement 2 is the correct explanation for Statement 1* - While both statements describe features of Pemphigus vulgaris, the tombstone appearance is a descriptive finding, not an explanatory mechanism *Incorrect: Statements 1 and 2 are incorrect* - Both statements are medically accurate descriptions of Pemphigus vulgaris features *Incorrect: Statement 1 is incorrect* - Statement 1 correctly describes the cardinal clinical and histopathological features of Pemphigus vulgaris
Question 9: A 45-year-old develops dysphagia 3 months post thyroidectomy. Most likely cause?
- A. Recurrent tumor
- B. RLN palsy
- C. Adhesions (Correct Answer)
- D. Esophageal injury
Explanation: ***Adhesions*** - **Adhesions** are the **most common cause** of delayed dysphagia occurring 3 months post-thyroidectomy. - **Perithyroidal and periesophageal adhesions** develop as part of the healing process and can cause esophageal compression, restriction of laryngotracheal mobility, or tethering of the esophagus. - The **3-month timeline** is classic for scar tissue maturation and adhesion formation, which peaks between 2-6 months post-operatively. - Patients typically describe **mechanical dysphagia** (difficulty with solid foods initially) and a sensation of tightness or fullness in the neck. - Management is usually **conservative** with time and reassurance, though severe cases may require surgical adhesiolysis. *Esophageal injury* - **Esophageal injury** during thyroidectomy is **extremely rare** (<0.1% incidence) due to the anatomical plane of dissection. - If it occurs, it typically presents **immediately or within days** post-operatively with severe symptoms such as fever, mediastinitis, subcutaneous emphysema, chest pain, and sepsis. - A **3-month delayed presentation** would be highly unusual and not the "most likely" cause in this clinical scenario. *RLN palsy* - **Recurrent laryngeal nerve (RLN) palsy** causes **hoarseness and voice changes** due to vocal cord paralysis, not dysphagia. - While bilateral RLN injury can cause airway obstruction and aspiration, it does not typically cause true dysphagia (difficulty swallowing solids/liquids). - RLN palsy manifests **immediately post-operatively** when the patient is extubated, not months later. *Recurrent tumor* - **Recurrent thyroid cancer** causing dysphagia at 3 months post-operatively is **extremely unlikely**. - Tumor recurrence typically takes **months to years** to develop and would be accompanied by other findings such as a palpable neck mass, lymphadenopathy, or recurrent laryngeal nerve involvement. - The short time frame makes this diagnosis improbable unless dealing with anaplastic carcinoma, which is rare.
Question 10: Which of the following is the best indicator of prognosis of soft tissue sarcoma?
- A. Tumour size
- B. Nodal metastasis
- C. Histological type
- D. Tumour grade (Correct Answer)
Explanation: ***Tumour grade*** - **Tumor grade** quantifies the degree of cellular differentiation, mitotic activity, and necrosis within the tumor, reflecting its aggressive potential. - A **higher tumor grade** is directly associated with a poorer prognosis, increased risk of local recurrence, and distant metastasis in soft tissue sarcomas. *Tumour size* - While larger tumor size (e.g., >5 cm) is generally associated with a worse prognosis, it is primarily a factor in **staging**, not the most critical prognostic indicator. - **Tumor grade** provides more fundamental information about the biological aggressiveness of the tumor cells regardless of their current size. *Nodal metastasis* - **Nodal metastasis** in soft tissue sarcomas is relatively uncommon (less than 5% of cases) compared to carcinomas, and its presence is a significant negative prognostic factor. - However, because it is rare, it doesn't serve as the *primary* indicator for the majority of sarcoma patients, where tumor grade is more universally applicable. *Histological type* - The **histological type** (e.g., liposarcoma, leiomyosarcoma) helps classify the sarcoma, but different subtypes can have a wide range of biological behavior. - While certain types may have a generally better or worse prognosis, the **grade** *within* that histological type is a more precise predictor of individual patient outcomes.
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