General Pathology Practice Questions

Q: Arbiskov cells are seen in which of the following conditions?

Myeloblastoma. **Explanation:** **Arbiskov cells** (also known as Abrikossoff cells) are the characteristic histological feature of **Granular Cell Tumors**, historically referred to as **Myeloblastoma** (specifically, Granular Cell Myeloblastoma). 1. **Why Myeloblastoma is correct:** Granular cell tumors are benign neoplasms, likely of Schwann cell origin. Under the microscope, they consist of large, polygonal cells with abundant, eosinophilic, and coarsely granular cytoplasm—these are the **Arbiskov cells**. The granules represent an accumulation of lysosomes (PAS-positive and diastase-resistant). While the term "Myeloblastoma" is an older nomenclature, it remains a high-yield synonym in competitive exams like NEET-PG. 2. **Why the other options are incorrect:** * **Neuroblastoma:** Characterized by small round blue cells and **Homer-Wright rosettes** [1]. * **Leiomyosarcoma:** A malignant tumor of smooth muscle characterized by spindle cells with "cigar-shaped" nuclei and a fascicular growth pattern. * **Retinoblastoma:** Characterized by **Flexner-Wintersteiner rosettes** (pathognomonic) and Homer-Wright rosettes. **Clinical Pearls for NEET-PG:** * **Most common site:** The **tongue** is the most frequent location for Granular Cell Tumors. * **Pseudoepitheliomatous Hyperplasia (PEH):** The overlying epithelium in these tumors often shows marked hyperplasia, which can be mistaken for Squamous Cell Carcinoma (a common diagnostic pitfall). * **Immunohistochemistry (IHC):** These cells are strongly positive for **S-100**, confirming their neural (Schwann cell) origin. * **Staining:** The granules are **PAS-positive** and diastase-resistant. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 419-420.

Q: What is the term for localized Langerhans cell histiocytosis affecting the head and neck?

Eosinophilic granuloma. **Explanation:** **Langerhans Cell Histiocytosis (LCH)** is a spectrum of disorders characterized by the clonal proliferation of Langerhans cells (expressing CD1a, S100, and CD207/Langerin) [1]. The clinical presentation depends on the extent of involvement. **Why Eosinophilic Granuloma is correct:** **Eosinophilic Granuloma** is the most benign and localized form of LCH. It typically presents as a **solitary, osteolytic lesion** in the bones, most commonly affecting the skull (head), mandible (neck), ribs, or femur. It is usually seen in older children or young adults and carries an excellent prognosis. **Analysis of Incorrect Options:** * **A. Letterer-Siwe disease:** This is the **acute disseminated** (multisystem) form of LCH, typically occurring in infants under age 2. It involves multiple organs (skin, liver, spleen, bone marrow) and has a poor prognosis. * **B. Pulmonary LCH:** This is a localized form specifically affecting the lungs, almost exclusively seen in **adult smokers**. While localized, it is not the classic term for head and neck bone involvement. * **Hand-Schüller-Christian disease (Note):** Though not an option, this is the chronic disseminated form characterized by the classic triad of calvarial bone defects, diabetes insipidus, and exophthalmos. **NEET-PG High-Yield Pearls:** 1. **Birbeck Granules:** Pathognomonic electron microscopy finding; described as **"tennis-racket"** shaped pentalaminar structures [1]. 2. **Immunohistochemistry (IHC):** Positive for **CD1a, S100, and Langerin (CD207)** [1]. 3. **BRAF V600E Mutation:** Present in approximately 50% of LCH cases [1]. 4. **Radiology:** "Punched-out" radiolucent lesions without a sclerotic rim are characteristic in the skull. **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: Birbeck granules are characteristically present in which of the following cells?

Langerhans cell. **Explanation:** **Langerhans cells** are specialized dendritic cells (antigen-presenting cells) primarily located in the stratum spinosum of the epidermis. The pathognomonic ultrastructural feature of these cells is the **Birbeck granule** [1]. Under electron microscopy, these are rod-shaped, pentalaminar cytoplasmic organelles with a central striated line and a bulbous end, giving them a characteristic **"tennis racket" appearance** [1]. They contain the protein **Langerin (CD207)**, which is involved in the endocytosis and degradation of viruses [1]. **Analysis of Options:** * **Merkel cells (Option A):** These are neuroendocrine cells involved in light touch sensation. They contain membrane-bound dense-core neurosecretory granules, not Birbeck granules. * **Melanocytes (Option B):** These cells are derived from the neural crest and produce pigment. Their characteristic organelles are **melanosomes**, which contain melanin. * **Keratinocytes (Option D):** The predominant cells of the epidermis. They are characterized by intermediate filaments (keratins) and **Odland bodies** (lamellar bodies) in the upper layers, but lack Birbeck granules. **High-Yield Clinical Pearls for NEET-PG:** * **Langerhans Cell Histiocytosis (LCH):** A neoplastic proliferation of Langerhans cells [1]. Diagnosis is confirmed by the presence of Birbeck granules on EM or immunohistochemistry markers: **CD1a, S100, and Langerin (CD207)** [1]. * **Origin:** Unlike other skin cells, Langerhans cells originate from the **bone marrow** (monocyte-macrophage lineage). * **Function:** They capture antigens and migrate to local lymph nodes to present them to T-lymphocytes. **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: What is the most common extragonadal site for germ cell tumors?

Mediastinum. **Explanation:** Germ cell tumors (GCTs) typically arise in the gonads (testes and ovaries). However, during embryogenesis, primordial germ cells migrate from the yolk sac endoderm to the gonadal ridges. If these cells fail to reach the gonads or stray from the migratory path, they can give rise to **Extragonadal Germ Cell Tumors (EGGCTs)**, which always occur in midline structures. **Why Mediastinum is correct:** In the **adult population**, the **mediastinum** (specifically the anterior mediastinum) is the most common site for extragonadal germ cell tumors. They represent about 50-70% of all adult EGGCTs. **Analysis of Incorrect Options:** * **Sacrococcygeal region:** This is the most common site for extragonadal GCTs (specifically Teratomas) in **infants and children**, but it is less common than the mediastinum when considering the overall population or adult-specific data often tested in PG exams. * **Retroperitoneum:** This is the second most common site in adults. However, a primary retroperitoneal GCT must be distinguished from a metastatic deposit from an occult testicular primary (Burned-out tumor). * **Pineal gland:** This is a common site for intracranial GCTs (Germinomas) [1], but it is less frequent overall compared to the mediastinum. **High-Yield Clinical Pearls for NEET-PG:** 1. **Most common mediastinal GCT:** Teratoma (usually benign in females, potentially malignant in males). 2. **Klinefelter Syndrome (47, XXY):** Strongly associated with the development of mediastinal germ cell tumors. 3. **Tumor Markers:** Always check AFP (Yolk sac component) and ̢-hCG (Choriocarcinoma component) for diagnosis and monitoring. 4. **Rule of Thumb:** Any midline mass in a young adult should raise suspicion for a Germ Cell Tumor. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1140-1141.

Question 1

Non-caseating granuloma is characteristically seen in:

Accepted Answer

Sarcoidosis

Answer

Syphilis

Answer

Tuberculosis

Answer

Cat-scratch disease

Question 2

Down's syndrome is associated with mental retardation. Which of the following chromosomal abnormalities are not typically found in Down's syndrome?

Accepted Answer

Deletion of chromosome 21

Answer

Trisomy 21

Answer

Translocation involving chromosome 21 (e.g., t(13,21), t(21,21))

Answer

Mosaicism with trisomy 21

Question 3

Bone marrow in Amyloid Lightchain Amyloidosis shows which of the following features?

Accepted Answer

Bone marrow plasmacytosis

Answer

Granulomatous reaction

Answer

Fibrosis

Answer

Giant cell formation

Question 4

Which of the following is an example of a direct acting toxin?

Accepted Answer

Mercuric chloride

Answer

Acetaminophen

Answer

Carbon tetrachloride

Answer

Bromobenzene

Question 5

Arbiskov cells are seen in which of the following conditions?

Accepted Answer

Myeloblastoma

Answer

Neuroblastoma

Answer

Leiomyosarcoma

Answer

Retinoblastoma

Question 6

What is the term for localized Langerhans cell histiocytosis affecting the head and neck?

Accepted Answer

Eosinophilic granuloma

Answer

Letterer-Siwe disease

Answer

Pulmonary Langerhans cell histiocytosis

Answer

None of the above

Question 7

Birbeck granules are characteristically present in which of the following cells?

Accepted Answer

Langerhans cell

Answer

Merkel cell

Answer

Melanocyte

Answer

Keratinocyte

Question 8

What is the most common extragonadal site for germ cell tumors?

Accepted Answer

Mediastinum

Answer

Retroperitoneum

Answer

Sacrococcygeal region

Answer

Pineal gland

Question 9

Which of the following is associated with C-ANCA?

Accepted Answer

Proteinase 3

Answer

Myeloperoxidase

Answer

Alkaline phosphatase

Answer

Lactate dehydrogenase

Question 10

Dissolution of nuclear chromatin and fading of chromatin is known as:

Accepted Answer

Karyolysis

Answer

Pyknosis

Answer

Karyorrhexis

Answer

Emiocytosis

General Pathology — MCQs

General Pathology — MCQs

On this page

Practice by Chapter

Want unlimited practice?