Weekly Pathology Exam - March 7, 2026 (Section A: MCQs) | MCQ Quiz | OmpathStudy Kenya

Question 1

A 45-year-old woman undergoes imaging for unrelated abdominal pain, revealing a 3 cm incidental liver lesion. Given its suspected diagnosis as the most common benign liver tumor, which of the following diagnostic procedures should be avoided?

Accepted Answer

Percutaneous needle biopsy — The most common benign liver tumor is a cavernous hemangioma. Percutaneous biopsy is avoided due to the risk of significant hemorrhage from these vascular lesions.

Question 2

A 28-year-old woman on oral contraceptive pills presents with sudden onset severe RUQ pain and hypovolemic shock. Imaging reveals a ruptured hepatic mass. Which benign liver tumor is most likely?

Accepted Answer

Hepatocellular Adenoma — Hepatocellular adenomas are strongly associated with oral contraceptive use and carry a significant risk of spontaneous rupture and life-threatening intraperitoneal hemorrhage.

Question 3

A liver lesion in a 35-year-old male reveals a central stellate scar and radiating fibrous septa containing anomalous arteries and bile ductules. What is the most likely diagnosis?

Accepted Answer

Focal Nodular Hyperplasia (FNH) — Focal Nodular Hyperplasia is characterized by a central stellate scar and a 'spoke-wheel' vascular pattern. It is a regenerative response to a pre-existing vascular malformation.

Question 4

Which of the following risk factors is most strongly associated with the development of Hepatocellular Carcinoma (HCC) globally?

Accepted Answer

Chronic Hepatitis B Infection — Globally, chronic infection with HBV is the most common risk factor for HCC, particularly in endemic regions like Asia and sub-Saharan Africa.

Question 5

A 62-year-old male with chronic Hepatitis C and cirrhosis has a solitary liver mass. Which tumor marker, if 1000 ng/ml, is highly suggestive of HCC?

Accepted Answer

Alpha-fetoprotein (AFP) — Markedly elevated levels of Alpha-fetoprotein (AFP) are highly specific for HCC in the setting of chronic liver disease (though its sensitivity varies).

Question 6

A 70-year-old man with Primary Sclerosing Cholangitis (PSC) develops jaundice and an intrahepatic mass with normal AFP. Which primary liver malignancy is most consistent?

Accepted Answer

Cholangiocarcinoma — Cholangiocarcinoma arises from the bile duct epithelium. Risk factors include PSC, liver flukes, and Caroli disease. AFP is usually normal, but CA 19-9 may be elevated.

Question 7

A 58-year-old female presents with multiple bilateral liver lesions. She has no history of chronic liver disease. What is the most common diagnosis for malignant liver tumors in adults?

Accepted Answer

Metastatic Carcinoma — Metastatic disease (especially from colon, lung, or breast) is far more common than primary liver cancer in non-cirrhotic livers.

Question 8

A 2-year-old child presents with an enlarging abdomen and a malignant epithelial tumor with primitive mesenchymal stroma on biopsy. What is the diagnosis?

Accepted Answer

Hepatoblastoma — Hepatoblastoma is the most common liver tumor of early childhood (usually <3 years). Histology often shows epithelial cells and mesenchymal elements.

Question 9

Exposure to which of the following substances is a significant risk factor for developing hepatic Angiosarcoma?

Accepted Answer

Arsenic and Vinyl Chloride — Hepatic angiosarcoma is rare but strongly linked to environmental toxins like vinyl chloride, thorium dioxide (Thorotrast), and arsenic.

Question 10

Regarding Hepatocellular Carcinoma (HCC), which statement is correct concerning its variant forms?

Accepted Answer

Fibrolamellar HCC typically presents in young adults without cirrhosis — Fibrolamellar HCC is a distinct variant that occurs in young adults (males = females), is not associated with cirrhosis or HBV, and has a better prognosis.

Question 11

A 30-year-old female smoker on OCPs for 10 years has a 5 cm encapsulated liver mass. Which feature differentiates this (Adenoma) from Focal Nodular Hyperplasia (FNH)?

Accepted Answer

Absence of a central scar — Adenomas lack the central stellate scar and the anomalous bile ductules found in the fibrous septa of FNH.

Question 12

A 65-year-old male cirrhotic has an AFP of 1500 ng/ml. Which characteristic differentiates HCC from Cholangiocarcinoma in this context?

Accepted Answer

HCC often shows bile production histologically — Bile production by tumor cells is a pathognomonic histological feature of HCC. Cholangiocarcinoma is a mucin-producing glandular tumor.

Question 13

What percentage of Non-Hodgkin Lymphomas are of B-cell origin?

Accepted Answer

85-90% — Approximately 85% to 90% of NHLs are of B-cell origin, with the remainder being T-cell or NK-cell lymphomas.

Question 14

Which is the most common subtype of B-cell NHL?

Accepted Answer

Diffuse Large B-Cell Lymphoma (DLBCL) — DLBCL is the most common form of NHL, accounting for about 30-40% of adult cases.

Question 15

A 60-year-old woman with painless lymphadenopathy has BCL-2+, CD10+, CD20+ cells and a slow progression. What is the diagnosis?

Accepted Answer

Follicular Lymphoma — Follicular lymphoma is an indolent B-cell lymphoma characterized by a t(14;18) translocation involving BCL-2 and germinal center markers like CD10.

Question 16

Which translocation is required for the diagnosis of Mantle Cell Lymphoma?

Accepted Answer

t(11;14) — Mantle Cell Lymphoma is defined by the t(11;14) translocation, which leads to overexpression of Cyclin D1.

Question 17

A patient with NHL has CD5+, CD19+, CD22+, CD23− immunophenotype. Which lymphoma does this suggest?

Accepted Answer

Mantle Cell Lymphoma — Mantle cell lymphoma is CD5+ but CD23 negative. CLL is typically CD5+ and CD23 positive.

Question 18

Which organism is directly implicated in the pathogenesis of gastric MALT lymphoma?

Accepted Answer

Helicobacter pylori — Chronic gastrtitis caused by H. pylori provides the antigenic stimulus for B-cell proliferation in the stomach, leading to MALT lymphoma.

Question 19

What is the first-line treatment for early-stage gastric MALT lymphoma?

Accepted Answer

H. pylori eradication (antibiotics/PPI) — Most cases of early-stage gastric MALT lymphoma regress completely after eradication of H. pylori.

Question 20

A 55-year-old man with visual disturbances and IgM spike has a MYD88 mutation. What is the diagnosis?

Accepted Answer

Burkitt Lymphoma — Waldenström’s Macroglobulinemia is a lymphoplasmacytic lymphoma with an IgM paraprotein and high frequency of MYD88 L265P mutations.

Question 21

Why is plasmapheresis particularly effective in Waldenström's compared to IgG myeloma?

Accepted Answer

IgM is found primarily in the intravascular space — IgM is a large pentameric molecule that stays primarily within the blood vessels, making it easily removable via plasmapheresis to treat hyperviscosity.

Question 22

A child from sub-Saharan Africa with a jaw mass and 'starry sky' histology. What is the diagnosis?

Accepted Answer

Burkitt Lymphoma — Endemic Burkitt lymphoma often involves the mandible or maxilla and shows the classic 'starry sky' appearance (tingible body macrophages).

Question 23

Which oncogene is overexpressed in virtually all cases of Burkitt lymphoma?

Accepted Answer

MYC — Burkitt lymphoma is characterized by translocations (most commonly t(8;14)) that result in the overexpression of the MYC oncogene.

Question 24

What is the gold standard investigation for diagnosing NHL?

Accepted Answer

Excisional lymph node biopsy — An excisional biopsy is required to assess the tissue architecture (nodular vs. diffuse) which is essential for accurate NHL classification.

Question 25

What is the incidence of Non-Hodgkin Lymphoma per 100,000 population?

Accepted Answer

15-20 per 100,000 — The incidence of NHL is approximately 15-20 per 100,000, making it significantly more common than Hodgkin lymphoma.

Question 26

Which of the following best describes the spread pattern of NHL compared to Hodgkin Lymphoma?

Accepted Answer

NHL spread is often non-contiguous and extranodal — Unlike Hodgkin lymphoma, NHL often involves multiple non-contiguous lymph node stations and frequently involves extranodal sites (GI tract, skin, etc.).

Question 27

Which classification system is the current gold standard for lymphoma classification?

Accepted Answer

WHO classification — The World Health Organization (WHO) classification, based on morphology, immunophenotype, genetics, and clinical features, is the global standard.

Question 28

In lymphoid neoplasms, what molecular event precedes malignant transformation?

Accepted Answer

Antigen receptor gene rearrangement — Malignant transformation often occurs in cells that have already undergone physiological gene rearrangement of B- or T-cell receptors.

Question 29

A MALT lymphoma does NOT respond to antibiotic therapy for H. pylori. Which translocation explains this?

Accepted Answer

t(11;18) — The t(11;18)(q21;q21) translocation is associated with MALT lymphomas that are resistant to H. pylori eradication therapy.

Question 30

Small B-cell lymphoma involving the skin (MALT type) is often associated with which organism?

Accepted Answer

Borrelia burgdorferi — Cutaneous marginal zone lymphomas (MALT type) have been associated with Borrelia burgdorferi infection in certain geographic regions.

Question 31

A 14-year-old male has a large mediastinal mass and T-cell markers (CD1, CD2, CD5, TdT). What is the diagnosis?

Accepted Answer

T-cell Lymphoblastic Lymphoma/Leukemia — T-ALL/LBL typically presents in adolescent males as a mediastinal mass. TdT is a marker of immature lymphoblasts.

Question 32

Which translocation carries the worst prognosis in Precursor B-cell ALL?

Accepted Answer

t(9;22) (Philadelphia chromosome) — The t(9;22) (BCR-ABL1) is associated with a poor prognosis in B-ALL, especially in adults.

Question 33

What are 'proliferation centres' in CLL/SLL histology?

Accepted Answer

Clusters of larger prolymphocytes and paraimmunoblasts — Proliferation centers (pseudofollicles) containing prolymphocytes are pathognomonic for CLL/SLL in lymph node biopsies.

Question 34

A patient with CLL has Hb 9g/dL and platelets 80×10⁹/L. What Binet stage is this?

Accepted Answer

Stage C — Binet Stage C is defined by the presence of anemia (Hb <10g/dL) or thrombocytopenia (platelets <100x10^9/L).

Question 35

What combination therapy achieves complete remission in 69% of CLL patients?

Accepted Answer

FCR (Fludarabine, Cyclophosphamide, Rituximab) — FCR chemo-immunotherapy is a standard high-efficacy regimen for fit patients with CLL.

Question 36

A 62-year-old woman with asymptomatic nodular BCL-2+ lymphoma for 3 years. What is the management?

Accepted Answer

Watch and wait — Asymptomatic, low-bulk Follicular Lymphoma is often managed with a 'watch and wait' approach as early treatment does not improve overall survival.

Question 37

A 45-year-old alcoholic with severe pain and chalky white deposits on CT. Which mechanism is responsible for these deposits?

Accepted Answer

Fat saponification — In acute pancreatitis, lipase releases fatty acids which combine with calcium to form insoluble salts (saponification), seen as chalky white deposits.

Question 38

In acute pancreatitis, which histological finding distinguishes it from chronic pancreatitis?

Accepted Answer

Neutrophilic inflammation and enzymatic fat necrosis — Acute pancreatitis is characterized by edema, proteolysis, fat necrosis, and acute inflammation (neutrophils). Chronic pancreatitis is defined by irreversible fibrosis and atrophy.

Question 39

A patient with chronic pancreatitis develops steatorrhea. What is the underlying mechanism?

Accepted Answer

Loss of >90% of exocrine pancreatic function — Steatorrhea and malabsorption occur only when exocrine secretion (lipase, etc.) falls below 10% of normal levels due to parenchymal destruction.

Question 40

Which genetic mutation is found in 90% of pancreatic ductal adenocarcinoma cases?

Accepted Answer

KRAS — Activating mutations in the KRAS oncogene are the most common genetic alteration in pancreatic cancer, present in nearly all cases.

Question 41

A 65-year-old presents with painless jaundice and Courvoisier sign. Where is the tumor MOST likely located?

Accepted Answer

Head of the pancreas — Tumors in the head of the pancreas often obstruct the common bile duct, leading to painless jaundice and a palpable gallbladder (Courvoisier sign).

Question 42

Which precursor lesion leads to invasive pancreatic ductal adenocarcinoma?

Accepted Answer

PanIN (Pancreatic intraepithelial neoplasia) — PanINs are the microscopic precursor lesions that progress through stages (1-3) to invasive carcinoma.

Question 43

What is the name for recurrent migratory superficial thrombophlebitis in pancreatic cancer?

Accepted Answer

Trousseau syndrome — Trousseau syndrome (migratory thrombophlebitis) is a classic paraneoplastic manifestation of procoagulants released by pancreatic and lung adenocarcinomas.

Question 44

What is the KEY histological feature distinguishing serous cystadenoma from mucinous cystadenoma?

Accepted Answer

Presence of 'ovarian-type' stroma — Mucinous cystic neoplasms (which occur almost exclusively in females) are characterized by an 'ovarian-type' dense stroma.

Question 45

Which pancreatic cyst carries significant malignant transformation potential?

Accepted Answer

Intraductal papillary mucinous neoplasm (IPMN) — IPMNs and mucinous cystic neoplasms are precursors to invasive cancer, whereas serous cystadenomas are almost always benign.

Question 46

A pseudocyst differs from a true cyst in which fundamental way?

Accepted Answer

It lacks an epithelial lining — Pseudocysts are walled-off collections of secretions and necrotic debris lined by granulation tissue rather than epithelium.

Question 47

In Type 1 Diabetes, which HLA haplotypes confer the strongest susceptibility?

Accepted Answer

HLA-DR3 and HLA-DR4 — The HLA-DR3/DQ2 and HLA-DR4/DQ8 haplotypes are most strongly associated with the risk of developing Type 1 DM.

Question 48

What is the role of CD8+ T cells in the pathogenesis of Type 1 Diabetes?

Accepted Answer

They cause direct islet cell lysis — Type 1 DM is a T-cell-mediated autoimmune disease where CD8+ cytotoxic T cells directly destroy insulin-producing beta cells.

Question 49

Which foramen ovale closes in approximately 75% of individuals at birth?

Accepted Answer

Functional closure occurs when LA pressure exceeds RA pressure — Functional closure of the foramen ovale happens at birth when the left atrial pressure increases. In about 25% of people, it remains 'probe patent'.

Question 50

Anatomical closure of the ductus arteriosus occurs through which process?

Accepted Answer

Intimal proliferation and fibrosis (forming ligamentum arteriosum) — After functional closure by prostaglandins/oxygen changes, the ductus undergoes permanent anatomical fibrosis to become the ligamentum arteriosum.

Weekly Pathology Exam - March 7, 2026 (Section A: MCQs) | MCQ Quiz | OmpathStudy Kenya

Questions, Answers & Explanations