Endocrine Pathology Practice Questions

Q: Which of the following is a fibrosing type of thyroiditis?

Riedel's thyroiditis. **Explanation:** **Riedel’s Thyroiditis** is the correct answer because it is characterized by extensive **dense fibrous tissue replacement** of the thyroid parenchyma [1]. This fibrosis often extends beyond the thyroid capsule into adjacent neck structures (trachea, esophagus, recurrent laryngeal nerve), mimicking a malignancy [1]. It is now considered a manifestation of **IgG4-related systemic disease** [1]. On palpation, the thyroid is classically described as "stony hard" and fixed [1]. **Why other options are incorrect:** * **Hashimoto’s Thyroiditis:** While late-stage Hashimoto’s can show some fibrosis, its hallmark is **lymphocytic infiltration** with germinal center formation and the presence of **Hürthle cells** (oxyphilic metaplasia). It is the most common cause of hypothyroidism in iodine-sufficient areas. * **De Quervain’s Thyroiditis (Subacute Granulomatous):** This is typically a post-viral inflammatory condition. Histologically, it is characterized by **granulomatous inflammation** with multinucleated giant cells surrounding fragments of colloid, rather than extensive fibrosis. It is clinically associated with a painful, tender thyroid. **NEET-PG High-Yield Pearls:** * **Riedel’s Thyroiditis:** Look for the "Hard as wood/iron" thyroid. It is associated with other fibrosing conditions like retroperitoneal fibrosis, sclerosing cholangitis, and mediastinal fibrosis [1]. * **Microscopy:** Riedel's shows a dense collagenous stroma with a sparse inflammatory infiltrate (lymphocytes, plasma cells, and eosinophils). * **Differential:** Must be differentiated from the **fibrosing variant of Hashimoto’s** and **Anaplastic Carcinoma**; however, Riedel’s lacks the cellular atypia seen in malignancy. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1091-1092.

Q: Amyloid stroma is seen with which of the following conditions?

Medullary carcinoma of the thyroid. **Explanation:** **Medullary Carcinoma of the Thyroid (MTC)** is the correct answer because it is a neuroendocrine tumor derived from the **parafollicular C-cells** [2]. These cells secrete excessive amounts of **calcitonin**. The characteristic amyloid stroma seen in MTC is formed by the deposition of procalcitonin molecules that undergo misfolding into insoluble β-pleated sheets [1]. On histopathology, this amyloid appears as an extracellular eosinophilic material that shows **apple-green birefringence** under polarized light when stained with **Congo Red** [1]. **Why other options are incorrect:** * **Papillary Carcinoma (PTC):** The hallmark features are nuclear changes (Orphan Annie eye nuclei, nuclear grooves, pseudo-inclusions) and **Psammoma bodies** (laminated calcifications), not amyloid. * **Follicular Carcinoma:** This is characterized by capsular or vascular invasion [1]. It lacks both amyloid stroma and the specific nuclear features of PTC. * **Anaplastic Carcinoma:** This is a highly aggressive, undifferentiated tumor showing pleomorphic giant cells or spindle cells [1]. It does not produce calcitonin or amyloid. **High-Yield Pearls for NEET-PG:** 1. **Genetic Association:** MTC is associated with **RET proto-oncogene** mutations. It occurs sporadically (75%) or as part of **MEN 2A and 2B** syndromes [2]. 2. **Tumor Marker:** Serum **Calcitonin** is used for diagnosis and monitoring recurrence; **CEA** is also a useful marker [2]. 3. **IHC Marker:** MTC stains positive for **Calcitonin, Chromogranin, and Synaptophysin**. 4. **Precursor Lesion:** C-cell hyperplasia is the precursor in familial cases. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 430-431. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1102-1103.

Question 1

A 65-year-old female patient presented with a neck swelling that moved with deglutition, along with multiple episodes of diarrhea, hoarseness, mild dysphagia, and mild shortness of breath. Lab findings revealed raised serum calcitonin levels and hypercalcemia. From which embryonic structure is the gland responsible for this condition derived?

Accepted Answer

Thyroid parafollicular cells (C cells)

Answer

Parathyroid glands

Answer

Thymus

Answer

Adrenal medulla

Question 2

Which of the following is a fibrosing type of thyroiditis?

Accepted Answer

Riedel's thyroiditis

Answer

Hashimoto's thyroiditis

Answer

De Quervain's thyroiditis

Answer

All of the above

Question 3

Which of the following findings is not seen in hyperparathyroidism?

Accepted Answer

Punched-out lesions of the skull

Answer

Osteopenia

Answer

Renal stones

Answer

Brown tumors

Question 4

Amyloid stroma is seen with which of the following conditions?

Accepted Answer

Medullary carcinoma of the thyroid

Answer

Papillary carcinoma of the thyroid

Answer

Follicular carcinoma of the thyroid

Answer

Anaplastic carcinoma of the thyroid

Question 5

Calcitonin is a marker of which condition?

Accepted Answer

Medullary carcinoma of the thyroid

Answer

Prostate cancer

Answer

Pheochromocytoma

Answer

Pancreatic cancer

Question 6

What endocrine disorder is characterized by a "brown tumor"?

Accepted Answer

Hyperparathyroidism

Answer

Hypothyroidism

Answer

None of the above

Answer

All of the above

Question 7

Subperiosteal bone resorption is seen in which of the following conditions?

Accepted Answer

Hyperparathyroidism

Answer

Hypothyroidism

Answer

Hyperthyroidism

Answer

Hypoparathyroidism

Question 8

Pheochromocytoma does not arise from which of the following?

Accepted Answer

Adrenal cortex

Answer

Adrenal medulla

Answer

Extra-adrenal sites

Answer

Sympathetic chain

Question 9

Which of the following is not included in Sipple's syndrome?

Accepted Answer

Hyperthyroidism

Answer

Pheochromocytoma

Answer

Medullary carcinoma thyroid

Answer

Hyperparathyroidism

Question 10

Which of the following is a common cause of hyperparathyroidism?

Accepted Answer

All of the above

Answer

Carcinoma of parathyroid glands

Answer

Hyperplasia of parathyroid glands

Answer

Adenoma of parathyroid glands

Endocrine Pathology — MCQs

Endocrine Pathology — MCQs

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