KMU Past Paper Practice

Question:

A 10-year-old child with acute lymphoblastic leukemia undergoes molecular testing after B-cell lineage has been established. A fusion protein with constitutive tyrosine kinase activity is identified. Which genetic abnormality best explains this finding?

Options:

Correct Answer: BCR-ABL1 fusion

Explanation: BCR-ABL1 is an important molecular abnormality in a subgroup of B-ALL and produces abnormal tyrosine kinase signaling that promotes leukemic-cell survival and proliferation.

Question:

A child is diagnosed with B-lineage acute lymphoblastic leukemia. Cytogenetic analysis shows an increased number of chromosomes within the leukemic clone rather than a specific translocation. Which abnormality best describes this finding?

Options:

Correct Answer: Hyperdiploidy

Explanation: Hyperdiploidy refers to an increased chromosome number and represents an important genetic pattern in a subgroup of B-ALL.

Question:

An adolescent with acute lymphoblastic leukemia develops headache and neurological symptoms. The bone marrow already contains a confirmed lymphoblast population. Which pathological process best accounts for the new presentation?

Options:

Correct Answer: Infiltration of the central nervous system by lymphoblasts

Explanation: ALL may extend beyond marrow and blood to the central nervous system; neurological manifestations can therefore result from leukemic infiltration.

Question:

A 69-year-old woman presents with painless generalized lymphadenopathy. Lymph-node biopsy shows a mature small B-cell neoplasm, while significant peripheral blood lymphocytosis is absent. Which diagnosis best represents this tissue-predominant manifestation?

Options:

Correct Answer: Small lymphocytic lymphoma

Explanation: CLL and SLL are closely related manifestations of the same mature B-cell neoplasm; predominant lymph-node involvement favors the designation SLL.

Question:

Flow cytometry in an elderly patient demonstrates a clonal mature B-cell population suspected to represent CLL. Compared with many other mature B-cell neoplasms, which additional immunophenotypic feature supports this interpretation?

Options:

Correct Answer: Weak CD20 and weak surface immunoglobulin expression

Explanation: CLL cells characteristically show relatively weak CD20 and surface immunoglobulin expression compared with many other mature B-cell lymphomas.

Question:

A patient with a plasma-cell neoplasm has a monoclonal immunoglobulin composed predominantly of free light chains without a major intact heavy-chain component. Which type of multiple myeloma best fits this pattern?

Options:

Correct Answer: Light-chain myeloma

Explanation: Light-chain myeloma is characterized predominantly by production of monoclonal free immunoglobulin light chains rather than intact immunoglobulin molecules.

Question:

A 61-year-old patient has a localized mass composed of clonal plasma cells at a single site. Evaluation does not show the widespread marrow involvement characteristic of disseminated myeloma. Which plasma-cell neoplasm is most appropriate?

Options:

Correct Answer: Plasmacytoma

Explanation: A plasmacytoma is a localized clonal plasma-cell tumor, whereas multiple myeloma characteristically involves multiple marrow sites.

Question:

Bone-marrow examination in a plasma-cell neoplasm shows cells with deeply basophilic cytoplasm. Which cellular feature most directly accounts for this staining pattern?

Options:

Correct Answer: Abundant rough endoplasmic reticulum

Explanation: Plasma cells synthesize large amounts of immunoglobulin, requiring abundant rough endoplasmic reticulum and producing strongly basophilic cytoplasm.

Question:

A patient with multiple myeloma shows evidence of disease progression. Molecular testing demonstrates a newly acquired abnormality affecting a pathway known to promote cellular growth. Which change is recognized as a secondary abnormality during progression?

Options:

Correct Answer: RAS pathway abnormality

Explanation: Additional abnormalities involving pathways such as RAS may accumulate during myeloma progression and support further growth of the malignant plasma-cell clone.

Question:

A patient with suspected plasma-cell myeloma has a distinct monoclonal protein in serum. Which investigation is most useful for further characterizing the immunoglobulin type produced by the clone?

Options:

Correct Answer: Immunofixation

Explanation: Immunofixation characterizes a detected monoclonal immunoglobulin and helps identify the heavy- and light-chain type produced by the plasma-cell clone.

Question:

A 55-year-old man has generalized lymphadenopathy. Biopsy shows numerous classical Reed-Sternberg cells surrounded by lymphocytes, eosinophils, plasma cells and histiocytes without broad collagen bands. Which subtype is most likely?

Options:

Correct Answer: Mixed cellularity classical Hodgkin lymphoma

Explanation: Mixed cellularity Hodgkin lymphoma contains classical Reed-Sternberg cells within a prominent mixed inflammatory background of several reactive cell types.

Question:

Histological examination of a lymph node shows classical Hodgkin lymphoma with relatively few normal lymphocytes and a prominent population of highly atypical tumor cells. Which subtype best matches this pattern?

Options:

Correct Answer: Lymphocyte-depleted classical Hodgkin lymphoma

Explanation: Lymphocyte-depleted classical Hodgkin lymphoma shows relatively sparse normal lymphocytes with more conspicuous atypical malignant cells.

Question:

A lymph-node specimen is diagnosed as classical Hodgkin lymphoma. Viral studies demonstrate Epstein-Barr virus within the malignant B-cell-derived population. Which interpretation is most appropriate?

Options:

Correct Answer: EBV can provide survival signals in a proportion of cases

Explanation: EBV is associated with a subset of classical Hodgkin lymphomas and can contribute survival signaling, but it is not present in every case.

Question:

A patient develops a malignant T-cell proliferation after infection with a human retrovirus. Which lymphoma is most strongly associated with this infectious agent?

Options:

Correct Answer: Adult T-cell leukemia/lymphoma

Explanation: HTLV-1 is the characteristic infectious association of adult T-cell leukemia/lymphoma and promotes abnormal T-cell proliferation and survival.

Question:

A lymphoma involving the nasal region is classified as an extranodal NK/T-cell neoplasm. Which infectious agent has the strongest association with this entity?

Options:

Correct Answer: Epstein-Barr virus

Explanation: Extranodal NK/T-cell lymphoma has a strong association with EBV, making viral association an important pathological clue to this entity.

Question:

An immunocompromised patient develops a lymphoma presenting predominantly as a malignant body-cavity effusion without a typical solid nodal mass. Which viral association best fits this lymphoma?

Options:

Correct Answer: HHV-8

Explanation: Primary effusion lymphoma is characteristically associated with HHV-8 and may present as malignant fluid accumulation in body cavities.

Question:

A pathologist examines an enlarged lymph node containing a relatively uniform population of atypical lymphoid cells replacing much of the normal tissue. Which feature most strongly favors lymphoma over a reactive lymph-node response?

Options:

Correct Answer: Monomorphic abnormal lymphoid population

Explanation: Many lymphomas produce a relatively monomorphic neoplastic population, whereas reactive nodes typically contain a heterogeneous mixture of lymphoid and inflammatory cells.

Question:

A patient has persistent painless lymphadenopathy and lymphoma is suspected. The clinician wants the pathologist to assess both the abnormal lymphoid cells and their arrangement within the node. Which specimen approach best serves this purpose when feasible?

Options:

Correct Answer: Excisional lymph-node biopsy

Explanation: Excisional biopsy preserves lymph-node architecture, allowing evaluation of both cellular morphology and the nodular, diffuse or other growth pattern needed for lymphoma classification.

Question:

A lymph-node biopsy shows an abnormal follicular pattern. The pathologist applies antibodies directly to tissue sections to determine whether the cells express markers supporting mature B-cell differentiation. Which investigation is being used?

Options:

Correct Answer: Immunohistochemistry

Explanation: Immunohistochemistry detects lineage and differentiation markers directly within tissue while preserving the relationship between marker expression and lymph-node architecture.

Question:

A lymphoid malignancy is being classified according to its normal cellular counterpart. The tumor expresses mature T-cell markers and lacks features of an immature precursor neoplasm. Which category of lymphoid neoplasm is most appropriate?

Options:

Correct Answer: Mature T-cell/NK-cell neoplasm

Explanation: WHO-style classification groups lymphoid tumors by lineage and maturation stage; mature T-lineage tumors therefore belong to the mature T-cell/NK-cell category.