The graphical representation for flow cytometry analysis is done by which of the following?
Fluorescence in situ hybridization (FISH) is required in which of the following interpretations of Her2/neu?
INI-CET 2021 - Pathology INI-CET Practice Questions and MCQs
Question 11: The graphical representation for flow cytometry analysis is done by which of the following?
- A. Pie chart, dot plot
- B. Histogram, dot plot (Correct Answer)
- C. Line diagram, dot plot
- D. Bar diagram, dot plot
Explanation: ***Histogram, dot plot*** - **Histograms** are used in flow cytometry to display the distribution of a single parameter (e.g., cell size, fluorescence intensity) across the cell population. - **Dot plots** are used to visualize the relationship between two or more parameters, allowing for the identification of distinct cell populations based on multiple characteristics. *Pie chart, dot plot* - **Pie charts** are typically used to represent proportions of a whole, which is not the primary way flow cytometry data is presented for detailed cell analysis. - While dot plots are correct, the combination with pie charts makes this option less accurate for typical flow cytometry analysis. *Line diagram, dot plot* - **Line diagrams** are generally used to show trends over time or continuous relationships, which is not the standard graphical representation for direct flow cytometry output. - Although dot plots are used, the inclusion of line diagrams makes this option incorrect in the context of typical flow cytometry data visualization. *Bar diagram, dot plot* - **Bar diagrams** are often used for comparing discrete categories or counting occurrences, not for displaying continuous distributions or multi-parameter relationships in flow cytometry directly. - While dot plots are correct, the pairing with bar diagrams does not represent the common and most informative graphical methods for flow cytometry analysis.
Question 12: Fluorescence in situ hybridization (FISH) is required in which of the following interpretations of Her2/neu?
- A. All of the options
- B. 2+ (Correct Answer)
- C. 1+
- D. 3+
Explanation: ***Correct: 2+*** A **Her2/neu immunohistochemistry (IHC) score of 2+** is considered **equivocal**, meaning it's uncertain whether Her2/neu is overexpressed. In such cases, **Fluorescence In Situ Hybridization (FISH)** is required to determine the amplification status of the *HER2* gene, which guides treatment decisions regarding anti-HER2 therapy (trastuzumab) [1], [2]. The 2+ score shows incomplete and weak to moderate membrane staining in >10% of tumor cells, necessitating gene amplification confirmation. *Incorrect: All of the options* While FISH is crucial for equivocal interpretations, it is **not required for all** possible Her2/neu IHC results [2]. Some scores (1+ and 3+) definitively indicate Her2/neu status without requiring confirmatory testing. Routinely performing FISH for all IHC scores would be unnecessary and costly. *Incorrect: 1+* An IHC score of **1+** indicates **no Her2/neu overexpression** (faint/barely perceptible incomplete membrane staining in >10% of tumor cells). In this situation, the patient is considered **Her2-negative**, and FISH testing is **not required** as the result is clearly negative. *Incorrect: 3+* An IHC score of **3+** indicates **clear Her2/neu overexpression** (strong, complete membrane staining in >10% of tumor cells) [1]. Patients with an IHC 3+ score are considered **Her2-positive**, and typically **FISH testing is not required** to confirm this result, as the overexpression is unequivocal [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 256-259. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Breast, pp. 1064-1066.