American Board of Internal Medicine (ABIM) Certification Practice Exam

Diagnosis of follicular lymphoma is confirmed by which method?

1. Bone marrow biopsy

2. Radiological imaging

3. Biopsy of a palpable lymph node and cytogenetic analysis

4. Flow cytometry

The correct answer is: Biopsy of a palpable lymph node and cytogenetic analysis

The diagnosis of follicular lymphoma is typically confirmed through a biopsy of a palpable lymph node, followed by cytogenetic analysis. This method is critical because follicular lymphoma is characterized by the presence of neoplastic follicle-forming cells, usually B-cells, that demonstrate specific histological features when examined microscopically. The biopsy allows for the assessment of cell morphology and architecture, which can reveal the follicular pattern associated with this type of lymphoma. Moreover, cytogenetic analysis, particularly looking for the t(14;18)(q32;q21) translocation involving the BCL2 gene, is essential in confirming the diagnosis. This genetic alteration is a hallmark of follicular lymphoma and is instrumental in distinguishing it from other types of lymphomas. Other potential diagnostic methods have their roles in the broader context of evaluating lymphoid tissue or assessing disease spread, but they are not definitive for the diagnosis of follicular lymphoma. Bone marrow biopsy may indicate involvement of the bone marrow but does not provide the necessary histopathological or genetic information. Radiological imaging is useful for staging or assessing disease extent but cannot confirm the diagnosis on its own. Flow cytometry is helpful in characterizing cell populations but is not the primary method for diagnosing follicular lymphoma