Endocrine Pathology Practice Questions

Q: RET gene mutation is associated with which malignancy?

Medullary carcinoma of the thyroid. **Explanation:** The **RET (REarranged during Transformation)** gene is a proto-oncogene located on chromosome 10 that encodes a receptor tyrosine kinase. Mutations in this gene lead to constitutive activation of signaling pathways, promoting uncontrolled cell growth [1]. 1. **Why Medullary Carcinoma of the Thyroid (MTC) is correct:** RET mutations are the hallmark of MTC. Approximately 95-100% of hereditary MTC (associated with **MEN 2A and 2B**) and about 50% of sporadic MTC cases harbor RET mutations [1]. In MEN 2 syndromes, germline mutations lead to C-cell hyperplasia, the precursor to MTC [2]. 2. **Why other options are incorrect:** * **Pheochromocytoma:** While pheochromocytoma *is* associated with RET mutations (as part of MEN 2A/2B), it is not the primary diagnostic association compared to MTC [1]. MTC is the most consistent feature of MEN 2. * **Lymphoma:** Associated with mutations/translocations like *c-MYC* (Burkitt), *BCL-2* (Follicular), or *BCL-6*. * **Renal Cell Carcinoma:** Primarily associated with *VHL* gene mutations (Clear cell RCC) or *MET* proto-oncogene (Papillary RCC). **High-Yield Clinical Pearls for NEET-PG:** * **MEN 2A (Sipple Syndrome):** MTC + Pheochromocytoma + Parathyroid Hyperplasia [1]. * **MEN 2B (Williams-Pollock Syndrome):** MTC + Pheochromocytoma + Mucosal Neuromas + Marfanoid habitus [2]. * **Prophylactic Thyroidectomy:** Recommended for children carrying germline RET mutations because MTC penetrance is nearly 100%. * **Papillary Thyroid Carcinoma:** Associated with **RET/PTC rearrangements** (different from the point mutations seen in MTC) [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1097-1098. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1102-1103.

Q: In which of the following conditions are 'Zellballens' typically seen?

Pheochromocytoma. **Explanation:** **1. Why Pheochromocytoma is correct:** 'Zellballen' (German for "cell balls") is the characteristic histological pattern seen in **Pheochromocytoma** and **Paragangliomas** [1]. This pattern consists of nests or clusters of large, polygonal chromaffin cells surrounded by a delicate vascular stroma and a peripheral layer of spindle-shaped **sustentacular cells** [1]. These cells contain granular cytoplasm due to the presence of catecholamine-containing membrane-bound vesicles [1]. **2. Why the other options are incorrect:** * **Gastric Carcinoma:** Typically presents with a glandular pattern (adenocarcinoma) or **Signet ring cells** (in diffuse types), where the nucleus is pushed to the periphery by a large mucin vacuole. * **Angiosarcoma:** A malignant vascular tumor characterized by anastomosing vascular channels lined by atypical, pleomorphic endothelial cells. * **Colon Carcinoma:** Characterized by malignant glands invading the basement membrane, often showing "dirty necrosis" (central luminal necrotic debris). **3. High-Yield Clinical Pearls for NEET-PG:** * **Rule of 10s for Pheochromocytoma:** 10% are bilateral, 10% are malignant, 10% are extra-adrenal (Paragangliomas), and 10% occur in children. * **Staining:** Sustentacular cells are positive for **S-100**, while the chief cells are positive for **Chromogranin** and **Synaptophysin**. * **Clinical Triad:** Episodic headache, sweating (diaphoresis), and tachycardia/palpitations in a hypertensive patient. * **Genetic Associations:** Often associated with MEN 2A, MEN 2B, VHL syndrome, and NF-1 [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 419-420. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, p. 1137.

Q: What is the most common histological type of thyroid carcinoma?

Papillary type. **Explanation:** Thyroid carcinomas are classified based on their histological origin. **Papillary Thyroid Carcinoma (PTC)** is the most common histological type, accounting for approximately **80–85%** of all thyroid malignancies. It typically presents as a slow-growing, painless thyroid nodule and has an excellent prognosis. **Why the other options are incorrect:** * **Follicular Carcinoma (Option A):** This is the second most common type (approx. 10–15%). Unlike PTC, it tends to spread hematogenously (to bone and lungs) rather than via lymphatics. * **Anaplastic Carcinoma (Option C):** This is the rarest (<2%) but most aggressive form. it typically occurs in elderly patients and has a very poor prognosis. * **Medullary Carcinoma (Option D):** This arises from the parafollicular C-cells (secreting calcitonin) and accounts for about 5% of cases. It can be sporadic or associated with MEN 2A/2B syndromes. **High-Yield Clinical Pearls for NEET-PG:** 1. **Risk Factor:** The most significant risk factor for Papillary Carcinoma is prior exposure to **ionizing radiation**. 2. **Histological Hallmarks:** Look for **Psammoma bodies** (laminated calcifications) and characteristic nuclear features: **Orphan Annie eye nuclei** (clear/ground-glass appearance) and **nuclear grooves/pseudoinclusions**. 3. **Spread:** PTC primarily spreads via the **lymphatics** to cervical lymph nodes. 4. **Investigation of Choice:** **FNAC** is the gold standard for diagnosis (except for Follicular carcinoma, which requires histopathology to see capsular/vascular invasion).

Q: All are true regarding MEN-I syndrome, except?

Autosomal recessive inheritance. **Explanation:** **MEN-I Syndrome (Wermer Syndrome)** is a hereditary cancer syndrome characterized by tumors of the "3 Ps": **P**arathyroid, **P**ancreas (Islet cells), and **P**ituitary [1]. 1. **Why Option A is the Correct Answer (The Exception):** MEN-I syndrome follows an **Autosomal Dominant** inheritance pattern, not autosomal recessive. A single mutated copy of the *MEN1* gene inherited from a parent is sufficient to predispose an individual to tumor development (following Knudson’s "two-hit" hypothesis at the cellular level). 2. **Analysis of Other Options:** * **Option B (Hyperparathyroidism):** This is the most common manifestation (80–95% of cases). It typically presents as multiglandular parathyroid hyperplasia and is often the first clinical sign of the syndrome [1]. * **Option C (Islet cell tumor):** Pancreatic neuroendocrine tumors (NETs) are the leading cause of morbidity and mortality in MEN-I. Common types include Gastrinomas (Zollinger-Ellison Syndrome) and Insulinomas [1]. * **Option D (Chromosome 11):** The *MEN1* gene is a tumor suppressor gene located on the long arm of **chromosome 11 (11q13)** [1]. It encodes the protein **Menin**. **High-Yield Clinical Pearls for NEET-PG:** * **The 3 Ps:** Parathyroid (Hyperplasia), Pancreas (Islet cell tumors/NETs), and Pituitary (most commonly Prolactinoma) [1]. * **Genetic Marker:** Mutation in the *MEN1* gene on Chromosome 11q13 [1]. * **Associated Lesions:** Patients may also present with angiofibromas, collagenomas, and lipomas. * **Contrast with MEN-II:** MEN-II involves the *RET* proto-oncogene (Chr 10) and is characterized by Medullary Thyroid Carcinoma and Pheochromocytoma [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1104-1140.

Question 1

RET gene mutation is associated with which malignancy?

Accepted Answer

Medullary carcinoma of the thyroid

Answer

Pheochromocytoma

Answer

Lymphoma

Answer

Renal cell carcinoma

Question 2

In which of the following conditions are 'Zellballens' typically seen?

Accepted Answer

Pheochromocytoma

Answer

Gastric carcinoma

Answer

Angiosarcoma

Answer

Colon carcinoma

Question 3

A 55-year-old obese woman complains of declining visual acuity. Funduscopic examination shows peripheral retinal microaneurysms. Urinalysis reveals 3+ proteinuria and 3+ glucosuria. Serum albumin is 3 g/dL, and serum cholesterol is 350 mg/dL. Which of the following mechanisms best explains these clinicopathologic findings?

Accepted Answer

Peripheral insulin resistance

Answer

Increased peripheral insulin uptake

Answer

Irregular insulin secretion

Answer

None of the above

Question 4

Which of the following is true about anaplastic carcinoma of the thyroid?

Accepted Answer

Common in elderly

Answer

Surrounding neck tissues are free

Answer

Lymphatic infiltration occurs

Answer

p53 mutation

Question 5

What is the most common histological type of thyroid carcinoma?

Accepted Answer

Papillary type

Answer

Follicular type

Answer

Anaplastic type

Answer

Medullary type

Question 6

All are true regarding MEN-I syndrome, except?

Accepted Answer

Autosomal recessive inheritance

Answer

Hyperparathyroidism

Answer

Islet cell tumor

Answer

Association with chromosome 11

Question 7

Which of the following is not considered a poor prognostic factor in neuroblastoma?

Accepted Answer

Evidence of gangliocytic differentiation

Answer

MYCN amplification

Answer

High mitosis-karyorrhexis index

Answer

Mutations of neuritogenesis genes

Question 8

All of the following are clinical features of MEN-II EXCEPT?

Accepted Answer

Pituitary tumour

Answer

Phaeochromocytoma

Answer

Medullary carcinoma of thyroid

Answer

Neuroma

Question 9

Which type of thyroid cancer is most commonly induced by radiation?

Accepted Answer

Papillary

Answer

Follicular

Answer

Anaplastic

Answer

Medullary

Question 10

A patient presented with neck swelling. Cytology showed parafollicular cells along with clusters of plasmacytoid and few spindle-shaped cells. What investigation should be done to follow up the patient?

Accepted Answer

Calcitonin

Answer

TSH level

Answer

Anti TPO antibody

Answer

TRH

Endocrine Pathology — MCQs

Endocrine Pathology — MCQs

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