FMGE 2025 - Pathology Practice Questions

Q: Basophilic stippling of red blood cells is most characteristically seen in which of the following conditions?

Lead poisoning. ***Lead poisoning*** - Lead inhibits several enzymes in the heme synthesis pathway and also inhibits **ribonuclease**, which is responsible for degrading residual ribosomal RNA (rRNA) in reticulocytes [1]. This leads to aggregation of ribosomes, appearing as coarse blue granules known as **basophilic stippling**. - While also seen in conditions like thalassemias and sideroblastic anemia, coarse basophilic stippling is a classic and highly characteristic finding in lead poisoning. *Iron deficiency anaemia* - The characteristic peripheral smear findings are **microcytic** and **hypochromic** red blood cells, which appear smaller and paler than normal [2]. - **Pencil cells** (elliptocytes) and **thrombocytosis** (an increased platelet count) are also commonly observed, but basophilic stippling is not a typical feature [2]. *Megaloblastic anemia* - This anemia, due to **vitamin B12** or **folate** deficiency, is characterized by **macro-ovalocytes** (large, oval red blood cells) and **hypersegmented neutrophils** on the peripheral smear [3]. - Other inclusions like **Howell-Jolly bodies** may be present, but basophilic stippling is not the defining feature. *Hereditary spherocytosis* - This is a genetic disorder affecting red blood cell membrane proteins, leading to the formation of **spherocytes** – small, round RBCs lacking central pallor. - The key findings are spherocytes on the smear and an increased **mean corpuscular hemoglobin concentration (MCHC)**, not basophilic stippling. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 418-419. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 590-591. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 594-595.

Q: In Pap smear cytology, which of the following is the most appropriate fixative used to preserve cellular details immediately after smearing?

95% ethanol. ***95% ethanol*** - This is considered the **gold standard fixative** for conventional **Pap smear** cytology because it acts rapidly to precipitate proteins, effectively preserving cellular and **nuclear detail** crucial for diagnosis. - Immediate fixation in 95% ethanol (or proprietary sprays containing alcohol) is essential to prevent **air-drying artifact**, which can severely distort nuclear morphology and render the smear diagnostically inadequate [1]. *50% formaldehyde* - Formaldehyde is typically used for **tissue fixation** (histopathology) rather than cytology smears, and this concentration is too dilute for effective cellular preservation. - Formaldehyde is an **additive fixative**, which acts differently than the preferred precipitant fixatives (like ethanol) used on thin smears. *70% ethanol* - While an alcohol fixative, **95% ethanol** is the recommended concentration for optimum dehydration and quick stabilization of the cell structures in a Pap smear. - 70% concentration may not fix the cells rapidly enough, potentially leading to suboptimal **chromatin preservation** compared to the higher concentration. *10% buffered formalin* - This is the routine fixative used globally for large **surgical pathology** specimens (biopsies and resections). - Formalin is generally not the preferred immediate fixative for thin-layer cytology slides compared to quick-acting alcohol, which provides superior **nuclear clarity** for Papanicolaou staining. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Female Genital Tract, pp. 1010-1011.

Q: Which genetic syndrome is caused by a deletion of the short arm of chromosome 5 (5p deletion)?

Cri-du-chat syndrome. ***Cri-du-chat syndrome*** - This syndrome is classically defined by a partial terminal deletion of the short arm of chromosome 5, designated as **5p deletion**. - Key clinical features include severe **intellectual disability**, **microcephaly**, and the characteristic high-pitched, monotonic **cat-like cry** that gives the syndrome its name. *Edward syndrome* - Edward syndrome is caused by an extra copy of chromosome 18 (**Trisomy 18**) [1]. - Clinical findings are often severe, including **micrognathia**, overlapping fingers, and **rocker-bottom feet** [1]. *Patau syndrome* - Patau syndrome is caused by an extra copy of chromosome 13 (**Trisomy 13**) [1]. - It is associated with severe midline defects such as **holoprosencephaly**, **cleft lip and palate**, and **polydactyly** [1]. *Turner syndrome* - Turner syndrome is a sex chromosome abnormality resulting from the absence of one X chromosome (45,X), making it a form of **monosomy X** [2]. - It primarily affects females, causing features like **short stature**, primary **amenorrhea** due to streak ovaries, and a **webbed neck** [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 168-169. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 175-177.

Q: FBN1 gene mutation is seen in which of the following genetic disorders?

Marfan syndrome. ***Marfan syndrome***- The **FBN1 gene** (located on chromosome 15) encodes the protein **fibrillin-1**, a major component of the extracellular matrix, deficiency of which leads to the clinical manifestations of Marfan syndrome.- **Fibrillin-1** is integral to the formation of elastic fibers; its defect causes issues in the skeletal, ocular, and cardiovascular systems [1].*Ehlers-Danlos syndrome*- This group of disorders is primarily caused by defects in **collagen synthesis** (e.g., **COL5A1**, **COL3A1**) or processing, leading to joint hypermobility and skin hyperextensibility [2].- It is not typically associated with the **FBN1** mutation.*Homocystinuria*- This disorder is an autosomal recessive metabolic error usually caused by a deficiency of the enzyme **cystathionine beta-synthase** (CBS) [3].- It involves abnormal metabolism of **methionine** and **cysteine**, leading to high levels of **homocysteine**, and is not linked to **FBN1**.*von Hippel-Lindau syndrome*- This is a predisposition syndrome caused by a mutation in the **VHL tumor suppressor gene** (located on chromosome 3).- It predisposes patients to various tumors, including **hemangioblastomas** and **renal cell carcinoma**, and has no association with **FBN1**. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 153-154. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 155-156. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 150-151.

Q: A 58-year-old male with history of multiple sexual partners presented with anorexia and jaundice. The biopsy shows ground-glass opacity in the cells. What is the most probable diagnosis?

Hepatitis B. ***Hepatitis B***- The biopsy finding of **ground-glass opacity** in hepatocytes is pathognomonic for chronic **Hepatitis B Virus (HBV)** infection, caused by the accumulation of **Hepatitis B surface antigen (HBsAg)** in the endoplasmic reticulum [1].- The patient's presentation of jaundice and anorexia, combined with the risk factor of **multiple sexual partners**, is highly suggestive of HBV transmission [3].*Hepatitis A*- Hepatitis A is transmitted via the **fecal-oral route** and rarely leads to chronic liver disease, making it unlikely given the patient's risk profile and chronic signs [2].- Histologically, it causes predominantly **acute panlobular hepatitis** without the distinguishing ground-glass inclusions.*Hepatitis C*- Histologic evaluation of Hepatitis C often reveals **lymphoid aggregates** within the portal tracts and prominent **steatosis** (fatty change), rather than ground-glass inclusions [1].- While transmitted parenterally and potentially sexually, the absence of the characteristic HCV histological features makes this diagnosis less likely.*Hepatitis D*- Hepatitis D is a **defective virus** requiring co-infection or superinfection with **Hepatitis B** for replication.- Although often co-existing with HBV, the specific **ground-glass appearance** results from the accumulation of **HBsAg**, the protein produced primarily by the Hepatitis B virus [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Liver and Gallbladder, pp. 843-844. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Liver and Gallbladder, pp. 844-845. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Liver and Gallbladder, p. 838.

Q: A diabetic male presented with seizures. Radiological examination shows a lesion. Histopathological examination shows liquefactive necrosis. What is the most important mechanism responsible for this?

Enzymatic degradation. ***Enzymatic degradation*** - Liquefactive necrosis, common in the brain (e.g., in stroke or brain abscess as suggested by the presentation in a **diabetic** patient), is defined by the complete dissolution of dead tissue into a viscous liquid mass [1]. - This dissolution is mediated by the robust release of **hydrolytic enzymes** from inflammatory cells (like **neutrophils** in an abscess) and the deceased parenchymal cells themselves, leading to the formation of a fluid-filled cavity [1]. *Mechanical* - Mechanical injury (trauma) is a *cause* of cell death and tissue damage, but it does not describe the specific biochemical process of liquefying the dead cells. - Mechanical factors primarily lead to **coagulative necrosis** initially if blood supply is compromised, or immediate cellular disruption, which is then processed by other mechanisms. *Ischemic* - Ischemia (lack of blood flow) is a common *cause* of necrosis (e.g., cerebral infarction), which often results in liquefactive necrosis in the CNS due to its high lipid content [1]. - While ischemia is the initiating event in many cases of liquefaction (especially stroke), the actual conversion of solid dead tissue into a liquid consistency requires the action of catabolic **enzymes**. *Pressure* - Pressure usually leads to generalized **atrophy** or localized **ischemia** (e.g., pressure sores or hydrocephalus), but it is not the fundamental molecular mechanism defining liquefactive necrosis. - Severe localized pressure that compromises microcirculation leads to ischemic injury, and the subsequent type of necrosis (liquefactive or coagulative) depends on the affected organ. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1268-1269.

Question 1

A 25-year-old woman presents with lower abdominal discomfort. The surgical image is given below. What is the most likely diagnosis?

Accepted Answer

Mature cystic teratoma

Answer

Immature teratoma

Answer

Endometrioma

Answer

Serous cystadenoma

Question 2

Basophilic stippling of red blood cells is most characteristically seen in which of the following conditions?

Accepted Answer

Lead poisoning

Answer

Megaloblastic anemia

Answer

Hereditary spherocytosis

Answer

Iron deficiency anaemia

Question 3

In Pap smear cytology, which of the following is the most appropriate fixative used to preserve cellular details immediately after smearing?

Accepted Answer

95% ethanol

Answer

70% ethanol

Answer

10% buffered formalin

Answer

50% formaldehyde

Question 4

Which genetic syndrome is caused by a deletion of the short arm of chromosome 5 (5p deletion)?

Accepted Answer

Cri-du-chat syndrome

Answer

Edward syndrome

Answer

Turner syndrome

Answer

Patau syndrome

Question 5

FBN1 gene mutation is seen in which of the following genetic disorders?

Accepted Answer

Marfan syndrome

Answer

Homocystinuria

Answer

von Hippel-Lindau syndrome

Answer

Ehlers-Danlos syndrome

Question 6

Acute hemolytic blood transfusion reactions are mediated by which type of hypersensitivity reaction?

Accepted Answer

Type II

Answer

Type I

Answer

Type III

Answer

Type IV

Question 7

A 58-year-old male with history of multiple sexual partners presented with anorexia and jaundice. The biopsy shows ground-glass opacity in the cells. What is the most probable diagnosis?

Accepted Answer

Hepatitis B

Answer

Hepatitis D

Answer

Hepatitis A

Answer

Hepatitis C

Question 8

A diabetic male presented with seizures. Radiological examination shows a lesion. Histopathological examination shows liquefactive necrosis. What is the most important mechanism responsible for this?

Accepted Answer

Enzymatic degradation

Answer

Ischemic

Answer

Mechanical

Answer

Pressure

FMGE 2025 — Pathology