NEET-PG 2013 - Pathology Practice Questions

Q: Which of the following is a major feature of Alagille syndrome?

Bile duct paucity. ***Bile duct paucity*** - **Bile duct paucity** is a hallmark histologic finding in Alagille syndrome, leading to **cholestasis** and liver disease. - This results from the reduced number of **intrahepatic bile ducts**, which are crucial for bile flow. *IHBR dilation* - **Intrahepatic biliary radical (IHBR) dilation** is characteristic of biliary obstruction, which is not the primary feature of Alagille syndrome. - Alagille syndrome is primarily a genetic condition leading to **hypoplasia or paucity** of bile ducts, not dilation. *PBC* - **Primary Biliary Cholangitis (PBC)** is an autoimmune disease primarily affecting **small intrahepatic bile ducts**, leading to their destruction and fibrosis [1]. - It is typically seen in middle-aged women and is characterized by **antimitochondrial antibodies (AMA)**, which are not features of Alagille syndrome. *PSC* - **Primary Sclerosing Cholangitis (PSC)** is a chronic cholestatic liver disease characterized by **inflammation and fibrosis** of both intrahepatic and extrahepatic bile ducts [2]. - PSC is strongly associated with **inflammatory bowel disease (IBD)** and **ANCA positivity**, which are distinct from the genetic basis and features of Alagille syndrome [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Liver and Gallbladder, pp. 864-865. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Liver and Gallbladder, pp. 865-866.

Q: All are features of Paget's disease except which of the following?

Affects only axial skeleton. ***Affects only axial skeleton*** - This statement is **FALSE** and therefore the correct answer to this "EXCEPT" question. - Paget's disease **can affect any bone in the body**, including both axial skeleton (spine, skull, pelvis) and appendicular skeleton (femur, tibia, humerus) [1]. - Common sites include: **pelvis (70%), spine, skull, femur, and tibia** [1]. - While it frequently affects axial bones, it is **not exclusive** to them. *Defect in osteoclasts* - This is a TRUE feature of Paget's disease. - The disease is characterized by **abnormal, hyperactive osteoclasts** with increased number of nuclei (up to 100 vs normal 3-5). - These osteoclasts show **excessive bone resorption activity** followed by disorganized bone formation [1]. - The primary defect involves **increased osteoclast activity and sensitivity to RANKL**. *Can lead to hearing loss* - This is a TRUE feature of Paget's disease. - Skull involvement can lead to **compression of cranial nerve VIII** (vestibulocochlear nerve) [1]. - Enlargement and disorganization of temporal bone can cause **conductive or sensorineural hearing loss**. - Occurs in approximately 30-50% of patients with skull involvement. *Can lead to bone cancer* - This is a TRUE feature of Paget's disease. - **Osteosarcoma** develops in approximately **1%** of Paget's disease patients. - Risk is higher in patients with **polyostotic disease** and long-standing involvement. - This is a rare but serious complication with poor prognosis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, pp. 1192-1194.

Q: Calcified pulmonary metastasis is seen in which carcinoma?

Thyroid carcinoma. ***Thyroid carcinoma*** - **Papillary** and **medullary thyroid carcinomas** can produce **calcified pulmonary metastases**. - In **papillary thyroid cancer**, calcification occurs due to **psammoma bodies** (concentrically laminated calcified structures). - In **medullary thyroid cancer**, calcification can occur through **dystrophic calcification** within the tumor tissue. - Other common causes of calcified lung metastases include **osteosarcoma** and **chondrosarcoma**. *Pancreatic carcinoma* - Pancreatic carcinoma rarely causes **calcified pulmonary metastases**; metastatic lesions are typically **non-calcified**. - Metastases are more commonly found in the **liver** and **peritoneum**. - Primary pancreatic tumors may show calcification, but metastases usually do not. *Endometrial carcinoma* - Endometrial carcinoma metastases to the lungs are usually **non-calcified** and appear as **soft tissue nodules**. - While it can metastasize to the lungs, **calcification** is not a typical feature of its pulmonary spread. *None of the options* - This option is incorrect because **thyroid carcinoma** (particularly papillary type) is a well-recognized cause of **calcified pulmonary metastases**. - Among epithelial malignancies, thyroid carcinoma is one of the classic causes of this finding.

Q: Which of the following statements about chronic osteomyelitis is false?

Involucrum is dead bone. ***Involucrum is dead bone*** - This statement is false because the **involucrum** is the layer of **new bone formation** that surrounds a segment of necrotic (dead) bone, known as the **sequestrum**, in chronic osteomyelitis [1]. - The involucrum represents the body's attempt to wall off the infection and dead bone, and thus, it is living, *reactive bone*, not dead bone [1]. *Reactive new bone formation* - This statement is true; **reactive new bone formation** occurs around infected or necrotic bone in chronic osteomyelitis, forming the **involucrum** [1]. - This process is a hallmark of the body's response to chronic infection and attempts to contain it. *Cloaca is an opening in involucrum* - This statement is true; a **cloaca** is a **fistulous tract** or opening in the **involucrum** that allows pus and necrotic debris from the infected area to drain to the skin surface. - This drainage is a common clinical sign of chronic osteomyelitis. *Sequestrum is hard and dense* - This statement is true; the **sequestrum** is a piece of **necrotic (dead) bone** that has become separated from living bone due to ischemia and infection [1]. - Due to the loss of blood supply and avascular necrosis, it appears **dense, hard, and radiodense** on imaging, representing devitalized bone tissue that is walled off from the body's immune response. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, pp. 1197-1198.

Q: Which condition is characterized by androgenesis (purely paternal genetic origin)?

Androgenic complete mole. ***Androgenic complete mole*** - A **complete hydatidiform mole** is characterized by the absence of maternal genetic material and a **purely paternal genetic origin** (androgenesis). - This typically results from the **fertilization of an 'empty' egg** by either two haploid sperm or one diploid sperm. *Turner's syndrome* - This condition is a **chromosomal disorder** in females where one of the two X chromosomes is missing or incomplete (45, X0). - It is not associated with androgenesis but rather with the **absence of a functionally complete X chromosome**. *Polycystic ovary syndrome (PCOS)* - PCOS is an **endocrine disorder** characterized by **hormonal imbalance** (high androgens), ovulatory dysfunction, and polycystic ovaries. - It involves maternal and paternal genetic contributions in a normal diploid set and is not related to androgenesis. *Androgenic partial mole* - A **partial hydatidiform mole** typically involves **triploidy**, where there are two sets of paternal chromosomes and one set of maternal chromosomes (e.g., 69, XXX or 69, XXY). - While it involves extra paternal genetic material, it is not purely paternal in origin, as a **maternal haploid set is also present**.

Q: Which layer of the epidermis is primarily involved in spongiosis?

Stratum spinosum. ***Stratum spinosum*** - **Spongiosis** is characterized by **intercellular edema** (fluid accumulation between cells) within the epidermis [1], primarily affecting the **stratum spinosum** [2]. - The cells of the stratum spinosum, known as **keratinocytes**, become separated by this edema, giving the tissue a "spongy" appearance on histology due to the preservation of **desmosomal attachments**. *Stratum basale* - The **stratum basale** is the deepest layer of the epidermis, responsible for **cell proliferation** and attachment to the basement membrane. - While edema can affect all epidermal layers in severe cases, spongiosis specifically refers to the intercellular edema most prominent in the stratum spinosum [2]. *Stratum corneum* - The **stratum corneum** is the outermost layer of the epidermis, composed of dead, flattened **keratinocytes** that provide a protective barrier. - Edema in this layer is less common and would not be described as spongiosis, which implies living cells with preserved intercellular junctions. *Stratum granulosum* - The **stratum granulosum** lies above the stratum spinosum and is characterized by cells containing **keratohyalin granules**. - While it can be affected by intercellular edema, the most pronounced and characteristic spongiosis occurs in the stratum spinosum where cells are still actively synthesizing keratin and have strong desmosomal connections [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, p. 636. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, p. 1166.

Q: What is the most common malignant tumor of the skeletal system?

Metastasis. ***Metastasis*** - **Skeletal metastasis** is overwhelmingly the most common malignant tumor involving bone, as many primary cancers (e.g., breast, prostate, lung) frequently spread to bone [1]. - While not originating in the bone, these metastatic deposits are malignant neoplasms within the skeletal system, making them the most prevalent. *Multiple myeloma* - This is a **primary malignancy of plasma cells** that arises in the bone marrow, causing destructive bone lesions. - It is the most common **primary malignant bone tumor** in adults, but still less common than metastatic disease. *Osteosarcoma* - This is the most common **primary malignant bone tumor** in **children and adolescents**, primarily affecting long bones [2]. - While a significant primary bone cancer, its incidence is lower than that of metastatic bone disease across all age groups [1]. *Chondrosarcoma* - This is a malignant tumor of **cartilage-forming cells** and is the second most common primary bone cancer in adults, after multiple myeloma [3]. - It is much less common than metastatic disease and osteosarcoma [1], [3]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Osteoarticular And Connective Tissue Disease, pp. 671-672. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, p. 1202. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, p. 1204.

Q: Lendrum's stain is done for:

Amniotic fluid embolism. ***Amniotic fluid embolism*** - **Lendrum's stain** (MSB - Martius Scarlet Blue) is specifically used to identify **fibrin**, **mucin**, and **squamous cells** in the pulmonary vasculature, which are characteristic findings in amniotic fluid embolism. [1] - This stain excellently demonstrates **fibrin** (stains red) and helps visualize components of amniotic fluid that embolize to the mother's lungs, leading to a severe, often fatal, obstetric emergency. [1] - Lendrum's method is particularly valuable in forensic pathology and autopsy diagnosis of this condition. *Air embolism* - Air embolism diagnosis relies on identifying **air bubbles** in the cardiovascular system, often confirmed by imaging studies or direct visualization during autopsy. [1] - Special stains are not typically used for direct detection of air in tissue sections. *Pulmonary embolism* - Pulmonary embolism, typically caused by a **blood clot**, is diagnosed by identifying **fibrin** and **red blood cells** within pulmonary arteries, often with stains like hematoxylin and eosin (H&E). [1] - While Lendrum's stain can demonstrate fibrin, it is specifically employed when amniotic fluid embolism is suspected, not for routine thromboembolic disease. *Fat embolism* - **Fat embolism** is diagnosed by demonstrating **fat globules** in the pulmonary microvasculature using **fat stains** like **Oil Red O** or **Sudan Black**, usually on frozen sections. - Lendrum's stain does not specifically highlight fat emboli. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Respiratory Tract Disease, pp. 322-324.

Q: Tensile strength of a wound becomes normal after:

Never. ***Never*** - A healed wound, even after complete maturation, only achieves about **80% of the original tissue's tensile strength** - The process of scar formation involves the realignment of collagen fibers and increased cross-linking, but it can **never perfectly replicate** the pre-injury tissue architecture and strength - This is a fundamental principle of wound healing - scar tissue is structurally different from normal tissue *6 months* - By 6 months, a wound's tensile strength has typically reached its **maximum potential** of approximately 80%, but this is still less than 100% of the original tissue's strength - This period marks the end of the significant remodeling phase, where collagen fibers are reorganized and strengthened *4 months* - At 4 months, the wound is still undergoing substantial **remodeling and strengthening**, achieving approximately 70-80% of eventual tensile strength - While considerable strength is gained by this time, further improvements continue for several more months *6 weeks* - At 6 weeks, the wound has achieved about **50-70% of its eventual tensile strength** - This stage is characterized by increased collagen deposition and cross-linking, making the wound clinically strong, but it is far from its maximum or normal strength

Q: When should semen analysis be done?

After liquefaction with thorough mixing. ***After liquefaction with thorough mixing*** - Semen analysis should be performed **after complete liquefaction** (typically within 20-30 minutes, maximum 60 minutes) followed by **thorough mixing**. - According to **WHO guidelines (2010, 2021)**, the sample must first liquefy completely at room temperature, then be mixed well before microscopic examination. - This ensures accurate assessment of **sperm concentration, motility, and morphology** without artifacts from viscous semen. - The standard practice is to examine within **60 minutes of collection** but only after liquefaction is complete. *After 30-60 mins irrespective of liquefaction* - The phrase "irrespective of liquefaction" is **incorrect** as analysis before complete liquefaction leads to inaccurate results. - Performing analysis on a non-liquefied sample can cause **underestimation of sperm motility** and difficulty in proper microscopic assessment. - Liquefaction status must be assessed before proceeding with analysis. *As early as possible* - Analyzing too early before **liquefaction** (which typically takes 20-30 minutes) will yield inaccurate results. - A viscous, non-liquefied sample impairs proper **sperm movement assessment** and mixing. *After 15-30 mins irrespective of liquefaction* - While 30 minutes may be sufficient for many samples to liquefy, the phrase "irrespective of liquefaction" makes this incorrect. - Some samples may require up to **60 minutes** to liquefy completely, and analysis should not proceed until liquefaction is confirmed.

Question 1

Which of the following is a major feature of Alagille syndrome?

Accepted Answer

Bile duct paucity

Answer

IHBR dilation

Answer

PBC

Answer

PSC

Question 2

All are features of Paget's disease except which of the following?

Accepted Answer

Affects only axial skeleton

Answer

Defect in osteoclasts

Answer

Can lead to hearing loss

Answer

Can lead to bone cancer

Question 3

Calcified pulmonary metastasis is seen in which carcinoma?

Accepted Answer

Thyroid carcinoma

Answer

Pancreatic carcinoma

Answer

Endometrial carcinoma

Answer

None of the options

Question 4

Which of the following statements about chronic osteomyelitis is false?

Accepted Answer

Involucrum is dead bone

Answer

Reactive new bone formation

Answer

Cloaca is an opening in involucrum

Answer

Sequestrum is hard and dense

Question 5

Which condition is characterized by androgenesis (purely paternal genetic origin)?

Accepted Answer

Androgenic complete mole

Answer

Turner's syndrome

Answer

Polycystic ovary syndrome (PCOS)

Answer

Androgenic partial mole

Question 6

Which layer of the epidermis is primarily involved in spongiosis?

Accepted Answer

Stratum spinosum

Answer

Stratum basale

Answer

Stratum corneum

Answer

Stratum granulosum

Question 7

What is the most common malignant tumor of the skeletal system?

Accepted Answer

Metastasis

Answer

Chondrosarcoma

Answer

Multiple myeloma

Answer

Osteosarcoma

Question 8

Lendrum's stain is done for:

Accepted Answer

Amniotic fluid embolism

Answer

Air embolism

Answer

Pulmonary embolism

Answer

Fat embolism

Question 9

Tensile strength of a wound becomes normal after:

Accepted Answer

Never

Answer

6 months

Answer

4 months

Answer

6 weeks

Question 10

When should semen analysis be done?

Accepted Answer

After liquefaction with thorough mixing

Answer

After 30-60 mins irrespective of liquefaction

Answer

As early as possible

Answer

After 15-30 mins irrespective of liquefaction

NEET-PG 2013 — Pathology