INI-CET 2022 - Pathology Practice Questions

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

3. ***3*** - The **corrected reticulocyte count (CRC)** is calculated to adjust for varying degrees of anemia, providing a more accurate assessment of bone marrow erythropoietic activity. The formula is: **CRC = observed reticulocyte % × (patient's HCT / normal HCT)**. - Assuming a normal hematocrit (HCT) of 45% and a direct hemoglobin to hematocrit conversion of 1:3 for 5 g/dL Hb (so HCT = 15%), then CRC = 9% × (15/45) = 9% × 1/3 = **3%**. *5* - This value is likely obtained by an **incorrect calculation** or by applying an inappropriate correction factor. - It does not properly account for the **severity of anemia** in the calculation of the corrected reticulocyte count [2]. *1.8* - This result may represent confusion with the **Reticulocyte Production Index (RPI)**, which further corrects for premature reticulocyte release by dividing CRC by a maturation time factor (typically 1.5-2 in severe anemia) [1]. - However, the question specifically asks for the **corrected reticulocyte count**, not the RPI, making this an inappropriate over-correction. *4.5* - This value might be a result of **dividing the observed reticulocyte count by a factor of 2**, which is not the standard correction for anemia. - It does not accurately reflect the **bone marrow's response** to the severe anemic state. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 586-587. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 590-591.

Q: A 7 year old child presents with fever, erythematous rash, and bone pain. $X$ - ray of the skull shows multiple lytic lesions. Skin biopsy shows prominent nuclear grooves with eosinophils as in the image below. Immunohistochemistry for S100, CD1a is also shown in the images below. What would be the diagnosis ?

Langerhans cell histiocytosis. ***Langerhans cell histiocytosis*** - The combination of **fever**, **erythematous rash**, **bone pain with lytic lesions**, and **prominent nuclear grooves with eosinophils** on skin biopsy, along with positive **S100** and **CD1a** immunohistochemistry, is highly characteristic of Langerhans cell histiocytosis [1]. - This condition is a clonal proliferation of Langerhans cells, which can affect bone, skin, and other organs, particularly in children [1]. *Erdheim-Chester disease* - This is a rare, non-Langerhans cell histiocytosis typically affecting adults, characterized by **xanthogranulomatous infiltration** of various organs. - While it can involve bones with **sclerotic lesions**, **lytic lesions** are uncommon, and the histological features with **nuclear grooves** and **eosinophils** are distinct from LCH. *Juvenile xanthogranuloma* - This is a benign, usually solitary, self-resolving histiocytic proliferation that typically presents as a **cutaneous nodule** in infants or young children. - Systemic involvement is rare, and it does not typically cause **lytic bone lesions** or exhibit the characteristic nuclear features of Langerhans cells. *Rosai-Dorfman disease* - This is a rare, benign histicocytic disorder characterized by **massive lymphadenopathy**, particularly cervical, and is often associated with the presence of **emperipolesis** (lymphocytes within histiocytes). - It does not typically present with **lytic bone lesions**, **eosinophilic infiltration**, or positive staining for **CD1a** or **S100** in the same manner as LCH. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, pp. 629-630.

Q: Iron in tissues is stained by:

Prussian blue. ***Prussian blue*** - The **Prussian blue reaction**, also known as **Perls' stain**, specifically detects **ferric iron (Fe³⁺)** in tissues [3]. - It forms a **bright blue precipitate** (ferric ferrocyanide) when ferric iron reacts with potassium ferrocyanide in an acidic solution. *Masson's trichrome* - This stain is primarily used to differentiate **collagen fibers** from muscle fibers, which appear blue/green and red, respectively [1]. - It does not specifically stain or identify iron deposits in tissues. *PAS* - The **Periodic acid-Schiff (PAS) stain** is used to identify **carbohydrates** such as glycogen, mucosubstances, and fungal cell walls, which appear magenta. - It is not used for the detection of iron. *Congo red* - **Congo red** is a specialized stain used for identifying **amyloid deposits**, which appear pink-red and show apple-green birefringence under polarized light [2]. - It is not used for staining iron in tissues. **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. 25-26. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of the Immune System, pp. 268-269. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 394-395.

Q: A 49 year old female presents with a breast lump. Which of the following findings is in accordance with basal-like breast cancer?

ER-, PR-, HER2-. ***ER-, PR-, HER2-*** - **Basal-like breast cancer** is characterized by its **triple-negative** status, meaning it does not express estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2 (HER2) [1]. - This specific immunophenotype is crucial for diagnosis and influences treatment strategies, as these cancers do not respond to therapies targeting these receptors [1]. *ER+, PR-, HER2-* - This profile describes a **hormone-sensitive** cancer (ER positive) but without PR or HER2 expression. - While it responds to endocrine therapies, it is distinct from basal-like cancer due to its ER positivity. *ER-, PR-, HER2+* - This profile indicates a cancer that is **HER2-positive**, meaning it overexpresses HER2, and can be targeted with anti-HER2 therapies like trastuzumab. - This is a separate molecular subtype of breast cancer often referred to as HER2-enriched, which is distinct from basal-like [2]. *ER+, PR+, HER2-* - This is the most common subtype, known as **luminal A** or **luminal B** depending on grade and Ki-67 expression, characterized by sensitivity to endocrine therapy [2]. - This hormone receptor-positive and HER2-negative profile is very different from the triple-negative basal-like breast cancer. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Breast, pp. 1064-1066. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Breast, p. 1060.

Question 1

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 2

A 7 year old child presents with fever, erythematous rash, and bone pain. $X$ - ray of the skull shows multiple lytic lesions. Skin biopsy shows prominent nuclear grooves with eosinophils as in the image below. Immunohistochemistry for S100, CD1a is also shown in the images below. What would be the diagnosis ?

Accepted Answer

Langerhans cell histiocytosis

Answer

Erdheim-Chester disease

Answer

Juvenile xanthogranuloma

Answer

Rosai-Dorfman disease

Question 3

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 4

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 5

Iron in tissues is stained by:

Accepted Answer

Prussian blue

Answer

Masson's trichrome

Answer

PAS

Answer

Congo red

Question 6

A 49 year old female presents with a breast lump. Which of the following findings is in accordance with basal-like breast cancer?

Accepted Answer

ER-, PR-, HER2-

Answer

ER+, PR-, HER2-

Answer

ER-, PR-, HER2+

Answer

ER+, PR+, HER2-

INI-CET 2022 — Pathology