INI-CET 2022 - Pathology PYQs Practice Questions

Q: The following is a histopathological image of thyroid pathology. What is the diagnosis?

Medullary carcinoma of thyroid. ***Medullary carcinoma of thyroid*** - This image shows sheets and nests of **polygonal to spindle-shaped cells**, which are characteristic of medullary thyroid carcinoma, especially when mixed with an **amyloid stroma** (seen as amorphous eosinophilic material) [2]. - The presence of **neuroendocrine features** and the production of **calcitonin** are hallmarks of these C-cell tumors [1], [2]. *Papillary carcinoma of thyroid* - Characterized by **papillary architecture**, **ground-glass (Orphan Annie eye) nuclei**, nuclear grooves, and intranuclear cytoplasmic inclusions. - These features are not prominently seen in the provided image. *Follicular carcinoma of thyroid* - Defined by an invasive growth pattern of **well-differentiated follicular cells** forming follicles, with either capsular or vascular invasion [2]. - The image does not show classic follicular architectural patterns or clear evidence of invasion in the absence of a capsule. *Anaplastic carcinoma of thyroid* - This is a highly aggressive and undifferentiated tumor with **marked pleomorphism**, bizarre giant cells, and high mitotic activity [2]. - While there is some pleomorphism, the overall pattern and cellular morphology in the image are more consistent with medullary carcinoma than the extreme anaplasia. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1102-1103. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 428-431. [Practice more Pathology PYQs on OnCourse]

Q: Best method for the detection of mutations with low allele frequency is:

Droplet digital PCR. ***Droplet digital PCR*** - **Droplet digital PCR (ddPCR)** offers superior sensitivity for detecting **low allele frequency mutations** by partitioning the sample into thousands of individual reactions. - This compartmentalization allows for the direct quantification of target DNA molecules without relying on a standard curve, making it highly accurate for rare mutation detection. *FISH* - **Fluorescence in situ hybridization (FISH)** primarily detects **chromosomal abnormalities** like translocations, deletions, or amplifications, rather than single-nucleotide variants or small indels with low allele frequencies [2]. - It visualizes genetic changes at a **cytogenetic level** on an intracellular basis, not typically for quantifying rare DNA mutations in a heterogeneous sample. *Sanger sequencing* - **Sanger sequencing** is the gold standard for **sequencing individual DNA fragments** but has a detection limit of around 15-20% for allele frequency, making it unsuitable for very low allele frequency mutations [1]. - It struggles to reliably detect minor alleles when they are present in a small proportion of the total DNA pool. *Nested PCR* - **Nested PCR** increases the sensitivity and specificity of amplification by using two sets of primers in a sequential manner but does not inherently provide the **quantification capability** or the same level of **low allele frequency detection** as ddPCR processes. - While sensitive for detecting target sequences, it is not designed for precise quantification of rare mutations in a background of wild-type sequences. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, p. 185. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 185-186. [Practice more Pathology PYQs on OnCourse]

Q: A baby is being evaluated for delayed developmental milestones. On examination, the child has hepatosplenomegaly. A microscopic image of the bone marrow evaluation is shown below. What is the most appropriate treatment?

Biological therapy. ***Biological therapy*** - The image likely shows a **Gaucher cell** (macrophage engorged with glucocerebroside, characterized by a "crinkled paper" or "crumpled tissue paper" cytoplasm) [1]. This is pathognomonic for **Gaucher disease**, which presents with **hepatosplenomegaly** and **developmental delay** in infants. - The standard treatment for Gaucher disease is **enzyme replacement therapy (ERT)**, which is a form of biological therapy replacing the deficient glucocerebrosidase enzyme [2]. *Macrolides for 4 months* - Macrolides are a class of **antibiotics** used to treat bacterial infections. - They are not indicated for lysosomal storage disorders like Gaucher disease, which is a **genetic metabolic disorder** [2]. *Steroid irrigation and antihistamines* - This treatment regimen is typically associated with allergic conditions or localized inflammatory responses, such as **allergic rhinitis** or **sinusitis**. - It bears no relevance to the systemic accumulation of lipids seen in Gaucher disease. *Repeat surgery* - While splenectomy was historically performed for massive splenomegaly in Gaucher disease, it does not address the underlying metabolic defect or systemic manifestations. - Furthermore, this case does not suggest a previous surgical intervention that requires repeating, and surgery is not the primary treatment for the metabolic disorder itself. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 162-163. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, p. 159. [Practice more Pathology PYQs on OnCourse]

Q: Which of the following structures is pathognomonic for chromoblastomycosis?

Sclerotic body. ***Sclerotic body*** - **Sclerotic bodies**, also known as **Medlar bodies** or **fumagoid cells**, are characteristic coin-shaped, thick-walled, septate, dematiaceous structures observed histologically in affected tissues. - Their presence is **pathognomonic** for chromoblastomycosis, a chronic fungal infection of the skin and subcutaneous tissue. *Asteroid body* - **Asteroid bodies** are typically found in **sporotrichosis**, representing an antigen-antibody complex surrounding fungal elements. - They are not characteristic of chromoblastomycosis. *Budding yeast* - **Budding yeast** forms are commonly seen in various fungal infections, such as **candidiasis** or **cryptococcosis**, but are not specific to chromoblastomycosis. [1] - This morphology indicates yeast proliferation but lacks the distinctive sclerotic appearance. *Negri body* - **Negri bodies** are eosinophilic, sharply demarcated neuronal cytoplasmic inclusions found in the diagnostic examination of **rabies** infection. - They are entirely unrelated to fungal infections like chromoblastomycosis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, p. 717. [Practice more Pathology PYQs on OnCourse]

Question 1

A male patient with hemoptysis. On examination, hilar mass was present. The histopathological image is shown below. Immunohistochemistry revealed that the cells were positive for p40. What is the diagnosis?

Accepted Answer

Squamous cell carcinoma

Answer

Adenocarcinoma lung

Answer

Small cell carcinoma

Answer

Large cell carcinoma

Question 2

The following is a histopathological image of thyroid pathology. What is the diagnosis?

Accepted Answer

Medullary carcinoma of thyroid

Answer

Papillary carcinoma of thyroid

Answer

Follicular carcinoma of thyroid

Answer

Anaplastic carcinoma of thyroid

Question 3

Best method for the detection of mutations with low allele frequency is:

Accepted Answer

Droplet digital PCR

Answer

FISH

Answer

Sanger sequencing

Answer

Nested PCR

Question 4

A baby is being evaluated for delayed developmental milestones. On examination, the child has hepatosplenomegaly. A microscopic image of the bone marrow evaluation is shown below. What is the most appropriate treatment?

Accepted Answer

Biological therapy

Answer

Macrolides for 4 months

Answer

Steroid irrigation and antihistamines

Answer

Repeat surgery

Question 5

Which of the following structures is pathognomonic for chromoblastomycosis?

Accepted Answer

Sclerotic body

Answer

Asteroid body

Answer

Budding yeast

Answer

Negri body

Question 6

The image below shows the life cycle of a virus. Which of the proteins of the virus act as oncogenes?

Accepted Answer

E6, E7

Answer

L1, L2

Answer

E1, E2, E5

Answer

E1, E2

Question 7

The Hb is 5 g/dL and the reticulocyte count is 9%. What is the corrected reticulocyte count?

Accepted Answer

3

Answer

5

Answer

1.8

Answer

4.5

Question 8

Match the following cell types/patterns (Column A) with their associated malignancies (Column B):

Column A (Cell types/patterns):
a) Faggot cell
b) Popcorn cell
c) Starry sky pattern
d) Cerebriform nuclei

Column B (Associated malignancies):
1) Acute promyelocytic leukemia
2) Lymphocyte-predominant Hodgkin's lymphoma
3) Burkitt lymphoma
4) Sezary syndrome

Accepted Answer

1-a, 2-b, 3-c, 4-d

Answer

1-a, 2-d, 3-c, 4-b

Answer

1-b, 2-c, 3-a, 4-d

Answer

1-b, 2-a, 3-d, 4-c

Question 9

A 35 year old woman presents with fatigue. Investigations revealed the following: Hb, 5 g/dL; MCH, 24; low MCV; leukocytes, 11,000/ uL, and platelets, 5 lakhs. The peripheral smear is shown below. What is the diagnosis?

Normal values:
- Mean cell volume (MCV); 90 ± 8 fL
- Mean cell Hb(MCH); 30 ± 3 pg

Accepted Answer

Iron - deficiency anemia

Answer

Essential thrombocytosis

Answer

Thalassemia major

Answer

Megaloblastic anemia

Question 10

Iron in tissues is stained by:

Accepted Answer

Prussian blue

Answer

Masson's trichrome

Answer

PAS

Answer

Congo red

INI-CET 2022 — Pathology