30 clinical MCQs in Hematopathology. What percentage of Non-Hodgkin Lymphomas are of B-cell origin?. Kenya, Africa and global revision.
Q1. What percentage of Non-Hodgkin Lymphomas are of B-cell origin?
Answer: 85%
Explanation: NHL is 85% B-cell and 15% T/NK-cell origin. This is a foundational fact frequently tested. ---
Q2. Which is the most common subtype of B-cell NHL?
Answer: Diffuse large B-cell lymphoma
Explanation: DLBCL is the most common NHL subtype overall. Follicular is second at 29%. ---
Q3. A 60-year-old woman has widespread painless lymphadenopathy. Biopsy shows BCL-2+, CD10+, CD20+ cells. The disease has been present for years with slow progression. What is the most likely diagnosis?
Answer: Follicular lymphoma
Explanation: Indolent course + BCL-2+/CD10+ markers + t(14;18) = classic follicular lymphoma presentation. ---
Q4. Which translocation is required for the diagnosis of Mantle Cell Lymphoma?
Answer: t(11;14)
Explanation: This juxtaposes the Cyclin D1 gene to the Ig heavy-chain gene → Cyclin D1 overexpression. Its presence is required for MCL diagnosis. ---
Q5. A patient with NHL has CD5+, CD19+, CD22+, CD23− immunophenotype. Which lymphoma does this suggest?
Answer: Mantle cell lymphoma
Explanation: Both MCL and CLL are CD5+/CD19+, but MCL is CD23− while CLL is CD23+. CD22+ also favours MCL. ---
Q6. Which organism is directly implicated in the pathogenesis of gastric MALT lymphoma?
Answer: Helicobacter pylori
Explanation: Gastric MALT lymphoma is strongly linked to H. pylori. Early-stage disease can regress completely with antibiotics alone. ---
Q7. What is the first-line treatment for early-stage gastric MALT lymphoma?
Answer: H. pylori eradication with antibiotics
Explanation: In early-stage gastric MALT, eliminating H. pylori can be curative. Chemotherapy is reserved for advanced or refractory disease. ---
Q8. A 55-year-old man presents with visual disturbances, fatigue and epistaxis. Serum protein electrophoresis shows a monoclonal IgM spike. Bone marrow biopsy reveals lymphoplasmacytoid infiltration. What gene mutation is present in 90% of cases?
Answer: MYD88
Explanation: This is Waldenström's macroglobulinaemia (LPL). MYD88 mutation is present in 90% and is near-diagnostic. ---
Q9. Why is plasmapheresis particularly effective in treating hyperviscosity in Waldenström's macroglobulinaemia compared to IgG myeloma?
Answer: IgM is mainly intravascular, making it accessible to plasmapheresis
Explanation: Because IgM stays in the bloodstream (unlike IgG which redistributes extravascularly), plasmapheresis efficiently removes it and rapidly relieves hyperviscosity. ---
Q10. A child from sub-Saharan Africa presents with a rapidly growing jaw mass. EBV is detected. Histology shows a 'starry sky' pattern with 95% proliferative index. What is the diagnosis?
Answer: Endemic Burkitt lymphoma
Explanation: Jaw mass + EBV + malaria-endemic region + starry sky histology + 95% mitotic index = classic endemic Burkitt. Translocation is t(8;14) → MYC overexpression. ---
Q11. Which oncogene is overexpressed in virtually all cases of Burkitt lymphoma?
Answer: MYC
Explanation: t(8;14) translocates MYC to the Ig heavy-chain locus → constitutive MYC expression during phases it should be OFF → uncontrolled proliferation. ---
Q12. What is the gold standard investigation for diagnosing NHL?
Answer: Trucut / whole lymph node biopsy
Explanation: FNA is specifically insufficient for NHL diagnosis. A biopsy providing tissue architecture is essential for accurate histological subtyping. ---
Q13. A 45-year-old HIV-positive patient develops a brain mass. MRI shows a ring-enhancing lesion. Biopsy confirms large B-cells with prominent nucleoli. What is the most likely diagnosis?
Answer: Primary CNS lymphoma
Explanation: Primary CNS lymphoma is more common in elderly and HIV+ patients. It is usually DLBCL type. Treat with high-dose methotrexate + cytosine arabinoside. ---
Q14. What is the standard first-line treatment for DLBCL?
Answer: R-CHOP × 6–8 cycles
Explanation: R-CHOP (Rituximab + Cyclophosphamide + Hydroxydaunorubicin + Vincristine + Prednisolone) given every 3 weeks is the backbone of DLBCL treatment. ---
Q15. Which subtype of DLBCL carries a worse prognosis?
Answer: Activated B-cell (ABC) type
Explanation: ABC type stains MUM1+ and activates the NFκB pathway. It has a worse prognosis compared to GCB type which stains BCL-6+. ---
Q16. A 35-year-old patient is diagnosed with lymphoma. Biopsy reveals TdT-positive cells. The presentation overlaps significantly with acute lymphoblastic leukaemia. What is the diagnosis?
Answer: Lymphoblastic lymphoma
Explanation: TdT (terminal deoxynucleotidyl transferase) positivity is the hallmark of lymphoblastic lymphoma — it is negative in ALL other NHL types. Treated with ALL protocols. ---
Q17. Which virus is associated with Adult T-cell Leukaemia/Lymphoma?
Answer: HTLV-1
Explanation: Human T-lymphotropic virus type 1 (HTLV-1) is the causative agent of Adult T-cell Leukaemia/Lymphoma. This is a must-know association. ---
Q18. A 70-year-old woman presents with skin rash, hepatosplenomegaly, lymphadenopathy and a polyclonal rise in IgG. What is the diagnosis?
Answer: Angioimmunoblastic T-cell lymphoma
Explanation: Key triad: lymphadenopathy + hepatosplenomegaly + skin rash + polyclonal IgG in an an elderly patient. Treated with chemotherapy or histone deacetylase inhibitors. ---
Q19. A patient presents with severe pruritus and psoriasis-like skin plaques. Years later they develop lymph node and bone marrow involvement. What is the diagnosis?
Answer: Mycosis fungoides
Explanation: Mycosis fungoides is a chronic cutaneous T-cell lymphoma starting with pruritus and skin plaques, eventually spreading to deeper organs. Treatment is phototherapy. ---
Q20. What distinguishes Sézary syndrome from Mycosis fungoides on blood film?
Answer: Circulating T-lymphoma cells with cerebriform nuclei
Explanation: Sézary syndrome = Sézary cells (CD4+ T-cells with cerebriform nuclei) in the blood + erythroderma + lymphadenopathy. This is pathognomonic. ---
Q21. Which lymphoma is most strongly associated with coeliac disease?
Answer: Enteropathy-associated T-cell lymphoma (EATL)
Explanation: EATL arises as a complication of coeliac disease and carries a very poor prognosis with poor treatment response. ---
Q22. Which serum marker is the most important prognostic indicator in NHL?
Answer: Serum LDH
Explanation: Elevated LDH reflects rapid tumour proliferation and high disease burden. It is a key component of the IPI and NCCN-IPI prognostic scoring systems. ---
Q23. A patient with follicular lymphoma is Stage III but completely asymptomatic. What is the recommended management?
Answer: Watch and wait
Explanation: Stage II–IV asymptomatic follicular lymphoma is managed with watch and wait. Treatment begins only when symptoms or complications develop. ---
Q24. What is the ONLY curative option for follicular lymphoma?
Answer: Allogeneic SCT
Explanation: Chemotherapy can achieve remission but is not curative in follicular lymphoma. Allogeneic SCT offers the only prospect of cure via graft-vs-lymphoma effect. ---
Q25. Anaplastic Large Cell Lymphoma (ALCL) is associated with which translocation and its resulting overexpressed protein?
Answer: t(2;5) → ALK
Explanation: t(2;5) causes overexpression of anaplastic lymphoma kinase (ALK). ALK+ ALCL has better prognosis than ALK− ALCL. Crizotinib specifically inhibits ALK. ---
Q26. What is the mechanism by which the t(14;18) translocation in follicular lymphoma promotes tumour survival?
Answer: BCL-2 overexpression prevents apoptosis
Explanation: t(14;18) brings BCL-2 under the Ig heavy-chain promoter → constitutive BCL-2 expression → cells survive longer than they should → lymphoma. ---
Q27. Which BRAF mutation is present in 99% of Hairy Cell Leukaemia cases?
Answer: BRAF V600E
Explanation: BRAF V600E mutation is present in 99% of hairy cell leukaemia cases, making it both diagnostic and a therapeutic target (vemurafenib). ---
Q28. In the NCCN-IPI for high-grade NHL, which factor carries the highest score?
Answer: Age >75 years
Explanation: In the NCCN-IPI: Age 75 = 3 points, the highest single score. LDH 3× normal = 2 points. All other factors = 1 point each. ---
Q29. A patient with relapsed DLBCL responds to R-ICE salvage chemotherapy. What is the next step?
Answer: Autologous stem cell transplantation
Explanation: In DLBCL patients who respond to salvage chemotherapy (R-ICE), autologous SCT consolidates the response and offers the best chance of long-term remission. ---
Q30. Which of the following correctly matches the infectious agent to its associated lymphoma?
Answer: HHV-8 → Primary effusion lymphoma
Explanation: HHV-8 causes primary effusion lymphoma and multicentric Castleman's disease. H. pylori → gastric MALT. EBV → Burkitt/Hodgkin. HTLV-1 → Adult T-cell leukaemia/lymphoma.