FMGE 2026 Practice Questions

Q: Foreigner with rice water stool

Cholera toxin. ***Cholera toxin*** - The **rice-water stool** is pathognomonic for **Vibrio cholerae** infection, which is mediated by the **cholera toxin**. - This toxin increases **cAMP** levels within enterocytes, leading to massive, secretory, non-inflammatory diarrhea and profound fluid loss. *Shigella toxin* - Associated with **bacillary dysentery**, characterized by **bloody stools**, mucus, and abdominal cramps rather than watery diarrhea. - This toxin, known as **Shiga toxin**, primarily inhibits protein synthesis by targeting the **60S ribosomal subunit**. *Heat labile E.Coli* - Also known as **Enterotoxigenic E. coli (ETEC)**, it causes **traveler's diarrhea** that is generally much milder than the epidemic cholera. - While it acts via a similar mechanism of increasing **cAMP**, it typically does not produce the extreme, rapidly dehydrating **rice-water stool** characteristic of cholera. *Rotavirus* - A major cause of **viral gastroenteritis** in infants and young children, typically presenting with watery diarrhea, fever, and vomiting. - Transmission is usually fecal-oral, and it is distinct from the **bacterial toxin**-mediated pathology seen in adult cholera cases.

Q: Factor VIII level of 50% in a patient with bleeding disorder is most suggestive of?

Von Willebrand disease. ***Von Willebrand disease*** - Type 1 Von Willebrand disease often presents with **reduced levels** of Von Willebrand factor (vWF), which serves as a carrier protein for **Factor VIII**. Because vWF protects Factor VIII from premature degradation in the plasma, mild to moderate deficiencies of vWF can lead to a secondary, proportional drop in **Factor VIII levels**. - A Factor VIII level of 50% is too high to be diagnostic of classic **Hemophilia A** (which typically presents with much lower levels, often <1%) and is more consistent with the partial deficiency seen in **vWD**, especially during stress or pregnancy where levels fluctuate. *Hemophilia A* - This is an X-linked recessive disorder characterized by a severe, primary deficiency of **Factor VIII clotting activity**; patients usually have levels significantly lower than 50% (commonly <5%). - Clinical presentation involves **deep tissue bleeding**, hemarthroses, and a prolonged **activated partial thromboplastin time (aPTT)** that does *not* correct with mixing studies, unlike vWD. *Glanzmann thrombasthenia* - This is a rare quantitative or qualitative defect of the **GPIIb/IIIa receptor** on the surface of platelets, which affects platelet aggregation. - Factor VIII levels are typically **normal** in this condition, as it is a pathology of primary hemostasis (platelet function) rather than secondary hemostasis (clotting factors). *Bernard–Soulier syndrome* - This condition is caused by a deficiency or dysfunction of the **GPIb/IX/V receptor** (von Willebrand factor receptor) on platelets, leading to impaired platelet adhesion. - Similar to Glanzmann thrombasthenia, this is a disorder of **platelet function**, and patients typically maintain **normal coagulation factor levels**, including Factor VIII.

Q: A 20 year old female presented with abdominal pain and passage of motile segments in the stool. She claims to have barbecue pork at her friends house. No other complaints. What is the most likely causative agent?

Taenia solium. ***Taenia solium*** - Infection is acquired by ingesting **undercooked pork** containing the larval stage (cysticercus), which then develops into the adult tapeworm in the human intestine. - The passage of **motile proglottids** (segments) in the stool is a classic clinical finding of **taeniasis**. *H. nana* - Also known as the **dwarf tapeworm**, it is the most common cestode infection but is typically transmitted by ingestion of eggs from contaminated food/water. - It does not have a direct association with the consumption of **pork**. *E. vermicularis* - Commonly known as the **pinworm**, it presents primarily with intense **perianal pruritus**, especially at night, rather than abdominal pain and segment passage. - Diagnosis is typically made via the **scotch tape test** to visualize eggs in the perianal region. *T. saginata* - This species is acquired by consuming **undercooked beef**, not pork, and presents with similar tapeworm infestation symptoms. - While it also causes passage of motile segments, the patient's specific history of consuming **pork** makes *Taenia solium* the more appropriate diagnosis.

Q: How does Epstein –Barr virus (EBV) cause Burkitt’s lymphoma?

Chromosomal translocation. ### ***Chromosomal translocation*** - EBV promotes lymphomagenesis in Burkitt's lymphoma by causing the **t(8;14) translocation**, which places the **c-MYC oncogene** on chromosome 8 under the constitutive control of the **immunoglobulin heavy chain promoter** on chromosome 14. - This dysregulation leads to **overexpression of c-MYC**, a transcription factor that drives rapid cell cycle progression and uncontrolled **B-cell proliferation**. ### *Primer insertion* - Primer insertion is a concept related to **polymerase chain reaction (PCR)** laboratory techniques and is not a mechanism of oncogenesis. - There is no documented mechanism where EBV causes cancer through the insertion of primers into the host cell machinery. ### *Receptor insertion* - Receptor insertion is generally related to the expression of **viral entry receptors** on a cell surface, enabling viral tropism. - This is not a mechanism involved in the malignant transformation of B-cells in Burkitt's lymphoma. ### *Viral integration into host genome* - While some viruses (like Retroviruses/HTLV-1) cause transformation via integration, **EBV persists as an episome** (extrachromosomal circular DNA) within the host cell nucleus rather than integrating into the host genome. - The oncogenic potential of EBV in Burkitt's lymphoma is driven by its ability to immortalize B-cells, creating a population susceptible to the specific genetic translocations mentioned above, rather than by direct insertional mutagenesis.

Q: A 40-year-old wom an presents with headache and undergoes evaluation for a brain tumor/ cerebellopontine angle. Histopathological examination reveals a tumor composed of Antoni A and Antoni B areas. Which of the following is the most sensitive immunohistochemical marker for this tumor?

S-100 protein. ***S-100 protein*** - S-100 is a protein expressed in cells of neural crest origin, and it serves as a highly **sensitive immunohistochemical marker** for **Schwannomas**. - The tumor described presents characteristic **Antoni A** (dense, hypercellular) and **Antoni B** (loose, hypocellular) areas, which are pathognomonic for Schwannoma. *Glial fibrillary acidic protein (GFAP)* - GFAP is an intermediate filament protein primarily found in **glial cells** like astrocytes and ependymal cells. - It is used to diagnose **gliomas** (e.g., astrocytoma, ependymoma) rather than nerve sheath tumors. *Epithelial membrane antigen (EMA)* - EMA is typically positive in **meningiomas**, which also frequently occur in the cerebellopontine angle. - While it is a useful marker in neuropathology, it is not the primary diagnostic marker for a Schwannoma. *c-KIT* - c-KIT (CD117) is the standard diagnostic marker for **gastrointestinal stromal tumors (GIST)**. - It is not a useful marker for tumors originating from Schwann cells or other neural sheath components.

Q: Which genetic abnormality is classically associated with Burkitt lymphoma?

t(8;14). ***t(8;14)*** - This translocation results in the **overexpression of the c-MYC oncogene** on chromosome 8 due to its placement next to the **immunoglobulin heavy chain (IgH) locus** on chromosome 14. - This specific genetic defect leads to high **cellular proliferation** rates, which is a hallmark of the diagnostically distinct **starry-sky appearance** seen in Burkitt lymphoma histology. *t(14;18)* - This translocation is characteristic of **follicular lymphoma**, resulting in the overexpression of the **BCL-2 anti-apoptotic protein**. - It prevents follicular center B-cells from undergoing apoptosis, leading to an expansion of these cells in the lymph nodes. *t(11;14)* - This translocation identifies **mantle cell lymphoma**, caused by the overexpression of **cyclin D1**. - Cyclin D1 promotes cell cycle progression from G1 to S phase, contributing to the aggressive growth of this subtype of non-Hodgkin lymphoma. *t(9;22)* - This is the famous **Philadelphia chromosome**, characterized by the formation of the **BCR-ABL fusion gene**. - It is the defining genetic abnormality in **chronic myeloid leukemia (CML)** and certain subsets of acute lymphoblastic leukemia (ALL).

Q: A peripheral blood smear is given, blasts count more than 60%. Immunophenotyping reveals positivity for CD13 and CD33. Negative CD19. What is the most likely diagnosis?

AML. ***AML*** - Myeloid lineage markers include **CD13** and **CD33**, which are hallmark immunophenotypic features of **Acute Myeloid Leukemia (AML)**. - A blast count greater than **20%** in the peripheral blood or bone marrow is diagnostic criteria for acute leukemia rather than a chronic process. *CML* - Typically characterized by **myeloid hyperplasia** with a full spectrum of myeloid production rather than a massive (>20%) blast crisis. - The presence of the **Philadelphia chromosome**, resulting in the **BCR-ABL1 fusion gene**, is the diagnostic driver for this condition. *ALL* - Typically positive for lymphoid markers like **CD19**, **CD10**, or **CD20** (B-cell lineage) or **CD3** (T-cell lineage). - The absence of lymphoid markers and presence of myeloid markers effectively rules out this acute leukemia subtype. *CLL* - A chronic condition characterized by the proliferation of **mature, small lymphocytes** with classic

Q: Testicular tumor on histopathology shows AFP negative and mildly elevated β -hCG. LDH? Most likely diagnosis is:

Seminoma. ***Seminoma*** - Seminomas are **germ cell tumors** characterized by **AFP negativity** and can present with **mildly elevated β-hCG** in 10-15% of cases (due to syncytiotrophoblastic giant cells). - **LDH levels** are frequently elevated in seminomas, serving as a useful **tumor marker** reflecting overall tumor burden. *Choriocarcinoma* - This tumor typically presents with **markedly elevated β-hCG** levels due to the abundance of syncytiotrophoblasts. - It is highly **aggressive** and often associated with early **hematogenous metastasis**, distinguishing it from the indolent clinical course of a pure seminoma. *Embryonal carcinoma* - These tumors are characterized by **non-seminomatous germ cell** differentiation and usually feature **elevated AFP** levels in addition to β-hCG. - They are clinically more **aggressive** than pure seminomas and often exhibit a **mixed histology** on biopsy. *Yolk sac tumor* - This tumor is pathognomonic for **markedly elevated AFP** (alpha-fetoprotein) levels, often showing **Schiller-Duval bodies** on histopathology. - It is the most common testicular tumor in **infants and children**, whereas seminomas are more common in **young adults (20-40 years)**.

Q: A 6-year-old child presents with joint pain and a purpuric rash over the buttocks and lower limbs. The rash is palpable and non -blanching. An image of the rash is shown. The child also complains of colicky abdominal pain. What is the most likely diagnos is?

Henoch –Schönlein purpura. ***Henoch-Schönlein purpura*** - This condition, also known as **IgA vasculitis**, classically presents with the triad of **palpable purpura** on dependent areas (lower limbs/buttocks), **arthritis/arthralgia**, and **abdominal pain** due to vasculitis of the bowel wall. - Diagnosis is supported by clinical presentation without significant thrombocytopenia, distinguishing it from platelet-related disorders. *Immune thrombocytopenic purpura* - Characterized by isolated **thrombocytopenia** resulting in **petechiae** and **ecchymoses** rather than palpable, raised lesions. - Abdominal pain and joint involvement are generally not features of this condition. *Acute rheumatic fever* - Presents with **migratory polyarthritis** and potential cardiac involvement following a **Group A Streptococcus** infection. - While it involves joints, it does not present with the characteristic palpable purpuric rash seen in vasculitis. *Kawasaki disease* - Manifests primarily as **prolonged high fever**, **conjunctivitis**, **mucosal changes** (strawberry tongue), and **polymorphous rash**. - The rash is typically not palpable purpura, and the condition is strongly associated with **coronary artery aneurysms**.

Q: A 19-year-old boy presents with long limbs and hypermobility of joints. Genetic analysis shows a mutation in the FBN1 gene. What is the most likely diagnosis?

Marfan syndrome. ***Marfan syndrome*** - This condition is caused by a mutation in the **FBN1 gene** on chromosome 15, which codes for **fibrillin-1**, a key component of connective tissue microfibrils. - Clinical features classically include **dolichostenomelia** (long limbs), **arachnodactyly** (long, thin fingers), **joint hypermobility**, and a high risk of **aortic root dilation** or dissection. *Ehlers–Danlos syndrome* - Primarily characterized by **skin hyperextensibility** and excessive tissue fragility, rather than the skeletal overgrowth seen in Marfan syndrome. - Mutations typically involve genes encoding **collagen** or enzymes involved in collagen processing (e.g., **ADAMTS2** or **PLOD1**), not the *FBN1* gene. *Homocystinuria* - Presents with a Marfanoid habitus but is distinct due to the presence of **intellectual disability** and **thrombotic events** (due to hypercoagulability). - It is an **autosomal recessive** metabolic disorder caused by **cystathionine beta-synthase deficiency**, not a fibrillin defect. *Loeys–Dietz syndrome* - While it shares features like aortic aneurysm and skeletal findings, it is often distinguished by **hypertelorism**, **bifid uvula**, and **cleft palate**. - It is caused by mutations in **TGFBR1** or **TGFBR2** genes, which regulate the TGF-beta signaling pathway, distinct from the *FBN1* pathology of Marfan syndrome.

Question 1

Foreigner with rice water stool

Accepted Answer

Cholera toxin

Answer

Shigella toxin

Answer

Heat labile E.Coli

Answer

Rotavirus

Question 2

Factor VIII level of 50% in a patient with bleeding disorder is most suggestive of?

Accepted Answer

Von Willebrand disease

Answer

Hemophilia A

Answer

Glanzmann thrombasthenia

Answer

Bernard–Soulier syndrome

Question 3

A 20 year old female presented with abdominal pain and passage of motile segments in the stool. She claims to have barbecue pork at her friends house. No other complaints. What is the most likely causative agent?

Accepted Answer

Taenia solium

Answer

H. nana

Answer

E. vermicularis

Answer

T. saginata

Question 4

How does Epstein –Barr virus (EBV) cause Burkitt’s lymphoma?

Accepted Answer

Chromosomal translocation

Answer

Primer insertion

Answer

Receptor insertion

Answer

Viral integration into host genome

Question 5

A 40-year-old wom an presents with headache and undergoes evaluation for a brain tumor/ cerebellopontine angle. Histopathological examination reveals a tumor composed of Antoni A and Antoni B areas. Which of the following is the most sensitive immunohistochemical marker for this tumor?

Accepted Answer

S-100 protein

Answer

Glial fibrillary acidic protein (GFAP)

Answer

Epithelial membrane antigen (EMA)

Answer

c-KIT

Question 6

Which genetic abnormality is classically associated with Burkitt lymphoma?

Accepted Answer

t(8;14)

Answer

t(14;18)

Answer

t(11;14)

Answer

t(9;22)

Question 7

A peripheral blood smear is given, blasts count more than 60%. Immunophenotyping reveals positivity for CD13 and CD33. Negative CD19. What is the most likely diagnosis?

Accepted Answer

AML

Answer

CML

Answer

ALL

Answer

CLL

Question 8

Testicular tumor on histopathology shows AFP negative and mildly elevated β -hCG. LDH? Most likely diagnosis is:

Accepted Answer

Seminoma

Answer

Choriocarcinoma

Answer

Embryonal carcinoma

Answer

Yolk sac tumor

Question 9

A 6-year-old child presents with joint pain and a purpuric rash over the buttocks and lower limbs. The rash is palpable and non -blanching. An image of the rash is shown. The child also complains of colicky abdominal pain. What is the most likely diagnos is?

Accepted Answer

Henoch –Schönlein purpura

Answer

Immune thrombocytopenic purpura

Answer

Acute rheumatic fever

Answer

Kawasaki disease

Question 10

A 19-year-old boy presents with long limbs and hypermobility of joints. Genetic analysis shows a mutation in the FBN1 gene. What is the most likely diagnosis?

Accepted Answer

Marfan syndrome

Answer

Ehlers–Danlos syndrome

Answer

Homocystinuria

Answer

Loeys–Dietz syndrome

FMGE 2026

Internal Medicine

Microbiology

Pathology

Pediatrics