Most common CNS tumor associated with NF1
The immunoglobulin most commonly involved in Multiple Myeloma is:
All of the following are features of juvenile CML except which of the following?
What is the most common cerebellar tumor in children?
Which of the following statements BEST characterizes the clinical significance of Barrett's esophagus?
Which of the following translocations is not associated with Down syndrome?
Which of the following is a feature not typically associated with Hereditary Spherocytosis?
Lendrum's stain is done for:
Rokitansky protuberances are seen in -
NEET-PG 2012 - Pathology NEET-PG Practice Questions and MCQs
Question 61: Most common CNS tumor associated with NF1
- A. Optic glioma (Correct Answer)
- B. Astrocytoma
- C. Bilateral acoustic neuroma
- D. Optic nerve schwannoma
Explanation: ***Optic glioma*** - **Optic gliomas** (specifically **pilocytic astrocytomas**) are the most common CNS tumor found in association with **Neurofibromatosis type 1 (NF1)** [1]. - These tumors typically affect the **optic nerve** and can cause vision impairment. *Optic nerve schwannoma* - **Schwannomas** are tumors arising from Schwann cells, and while they can affect cranial nerves, an **optic nerve schwannoma** is very rare and not characteristic of NF1. - The most common schwannoma associated with neurofibromatosis is a **vestibular schwannoma** (acoustic neuroma) in NF2, not NF1 [2]. *Astrocytoma* - While optic gliomas are a type of astrocytoma, simply stating "astrocytoma" is too broad; the specific location (optic nerve) and type (pilocytic) are key in NF1 [1]. - Other types of astrocytomas (e.g., glioblastoma) are not typically associated with NF1 as the *most common* CNS tumor. *Bilateral acoustic neuroma* - **Bilateral acoustic neuromas** (vestibular schwannomas) are the hallmark CNS tumor of **Neurofibromatosis type 2 (NF2)**, not NF1 [2]. - This symptom strongly points to NF2, a distinct genetic disorder from NF1 [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1319-1320. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 727-728.
Question 62: The immunoglobulin most commonly involved in Multiple Myeloma is:
- A. IgG (Correct Answer)
- B. IgM
- C. IgA
- D. IgD
Explanation: ***IgG*** - In Multiple Myeloma, the most commonly involved immunoglobulin is **IgG**, which is often produced in excess by malignant plasma cells [1][2]. - The presence of **monoclonal IgG** in serum is a key indicator of this malignancy, evident in diagnostic tests like serum protein electrophoresis. *IgM* - While **elevated IgM** levels can occur in other conditions like Waldenström's macroglobulinemia, it is not typically associated with Multiple Myeloma [2]. - IgM is produced by a different type of plasma cell and does not reflect the classic presentation of Multiple Myeloma. *IgA* - Although **IgA** can be involved in some cases of Multiple Myeloma, it is much less common than IgG [1][2]. - Patients with predominately **IgA Multiple Myeloma** are relatively rare compared to those with IgG. *IgD* - **IgD** myeloma is a very rare type of Multiple Myeloma, accounting for less than 2% of cases [1][2]. - It is not typically associated with the classic symptoms and conditions that characterize the more common IgG or IgA forms. **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. 608-609. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 616-617.
Question 63: All of the following are features of juvenile CML except which of the following?
- A. Fetal Hb is increased
- B. Lymphadenopathy
- C. Thrombocytopenia
- D. Philadelphia chromosome is positive (Correct Answer)
Explanation: ***Philadelphia chromosome is positive*** - **Juvenile Chronic Myeloid Leukemia (JCML)**, now known as **Chronic Myelomonocytic Leukemia (CMML)** of childhood, is characterized by the **absence** of the **Philadelphia chromosome (Ph chromosome)**. - The Ph chromosome, a t(9;22)(q34;q11) translocation forming the **BCR-ABL1 fusion gene**, is the hallmark of adult Chronic Myeloid Leukemia (CML), but not JCML. *Thrombocytopenia* - **Thrombocytopenia** (low platelet count) is a common feature in JCML due to ineffective hematopoiesis and bone marrow infiltration. - This contrasts with adult CML, where **thrombocytosis** (high platelet count) is more characteristic of the chronic phase. *Fetal Hb is increased* - An **increased level of fetal hemoglobin (HbF)** is a characteristic laboratory finding in children with JCML. - This elevation is related to the dysregulated hematopoiesis and is a useful diagnostic marker. *Lymphadenopathy* - **Lymphadenopathy** (enlarged lymph nodes) is a frequent clinical manifestation in JCML, reflecting the widespread infiltration of monocytic cells. - This is part of the systemic involvement seen in this aggressive myeloproliferative disorder.
Question 64: What is the most common cerebellar tumor in children?
- A. Ependymoma
- B. Medulloblastoma (Correct Answer)
- C. PNET
- D. Astrocytoma
Explanation: ***Medulloblastoma*** - **Medulloblastoma** is the most common **malignant** cerebellar tumor in children, accounting for about 20% of all childhood brain tumors [2]. - In the context of this question, medulloblastoma is considered the "most common cerebellar tumor" as it is the most frequently encountered **malignant** tumor requiring aggressive treatment. - These tumors arise from neuroectodermal cells in the cerebellum and are typically **highly aggressive**, often spreading through the cerebrospinal fluid (CSF) pathways [1], [2]. - Peak incidence is between 5-9 years of age, with a male predominance [1]. *Astrocytoma* - **Cerebellar pilocytic astrocytomas** are actually the most common **benign** cerebellar tumor in children and represent a significant portion of all cerebellar tumors [1]. - However, in competitive exam contexts, when asking about "most common cerebellar tumor," the question typically refers to **malignant tumors**, where medulloblastoma takes precedence. - **Pilocytic astrocytomas** are usually low-grade (WHO Grade I) and have an excellent prognosis, often presenting as cystic lesions with a mural nodule. *Ependymoma* - **Ependymomas** are the third most common posterior fossa tumor in children (after medulloblastoma and pilocytic astrocytoma). - They typically arise from the ependymal lining of the **fourth ventricle**, making them cerebellar-adjacent rather than primarily cerebellar tumors [3], [4]. - They account for about 10% of pediatric brain tumors and have an intermediate prognosis. *PNET* - **PNET (Primitive Neuroectodermal Tumor)** is a historical term that has largely been replaced by more specific classifications in the current WHO CNS tumor classification. - Medulloblastoma was previously classified as a type of PNET, but is now recognized as a distinct entity. - The term PNET is now rarely used in modern neuropathology practice, having been superseded by molecular and genetic classification systems. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 725-726. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1314-1315. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 726-727. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1312-1313.
Question 65: Which of the following statements BEST characterizes the clinical significance of Barrett's esophagus?
- A. Barrett's esophagus is a precancerous condition (Correct Answer)
- B. Barrett's esophagus involves metaplasia of esophageal cells
- C. Intestinal type is the most common type
- D. It does not predispose to SCC but to adenocarcinoma
Explanation: ***Predisposes to SCC*** - Barrett's esophagus primarily predisposes individuals to **adenocarcinoma**, not squamous cell carcinoma (SCC) [2][3]. - SCC is associated with other conditions, such as **smoking** and **chronic irritation**, not Barrett's [3]. *Intestinal type is the most common type* - The intestinal type is indeed **common** in Barrett's esophagus, but it's not the only type present [2]. - Barrett's esophagus can also have a **gastric** type, but the intestinal type predominates in adenocarcinoma risk. *Metaplasia of cells* - This condition is defined by **intestinal metaplasia**, where squamous epithelium is replaced by columnar epithelium [2]. - Metaplasia is a **hallmark** of Barrett's esophagus and crucial for its diagnosis [2]. *Precancerous condition* - Barrett's esophagus is considered a **precancerous condition** because it increases the risk of transitioning to esophageal adenocarcinoma [1][2]. - The progression from Barrett's to cancer is well-documented in medical literature [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 764-765. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Alimentary System Disease, pp. 348-349. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Gastrointestinal Tract, pp. 766-767.
Question 66: Which of the following translocations is not associated with Down syndrome?
- A. t(21;21)
- B. t(14;21)
- C. t(15;21)
- D. t(11;14) (Correct Answer)
Explanation: ***t (11: 14)*** - The **t(11;14) translocation** is commonly associated with **mantle cell lymphoma**, a B-cell non-Hodgkin lymphoma, and is not a cause of Down syndrome. - This translocation leads to the overexpression of the **cyclin D1 gene**, located on chromosome 11, which promotes cell growth and proliferation. *t (14; 21)* - This is a common **Robertsonian translocation** involving chromosomes 14 and 21, which results in an extra copy of chromosome 21 material [1]. - Individuals with this translocation can have **Down syndrome** because their cells end up with the equivalent of three copies of chromosome 21 [1]. *t (21; 21)* - This translocation is another type of **Robertsonian translocation** where two chromosome 21s fuse. - This specific translocation is rare and results in an extra copy of chromosome 21, leading to **Down syndrome** with a high recurrence risk in offspring. *t (15: 21)* - This is a **Robertsonian translocation** involving chromosomes 15 and 21, resulting in an extra copy of chromosome 21 material. - This translocation is a known cause of **Down syndrome** due to the dosage imbalance of genes on chromosome 21 [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 169-172.
Question 67: Which of the following is a feature not typically associated with Hereditary Spherocytosis?
- A. Gall stones
- B. Direct Coombs Positive (Correct Answer)
- C. Splenomegaly
- D. Increased Osmotic Fragility
Explanation: ***Direct Coomb's Positive*** - In Hereditary Spherocytosis, the **Coomb's test** is typically **negative**, indicating that hemolysis is not due to autoimmune factors. - Presence of **spherocytes** on the blood smear and increased fragility are hallmark findings, not antibodies against red cells [1]. *Splenomegaly* - **Splenomegaly** is common in Hereditary Spherocytosis as the spleen actively removes abnormal spherocytes from circulation [1]. - It can lead to **hypersplenism**, with resultant anemia and thrombocytopenia. *Increased Osmotic Fragility* - Increased osmotic fragility is a key feature of Hereditary Spherocytosis, as red blood cells are less able to withstand hypotonic solutions [1]. - This results from a defect in the red cell membrane, causing spherocyte shape and fragility. *Gall stones* - Patients may develop **gallstones** due to increased bilirubin from the breakdown of spherocytes, leading to **bilirubin stones** [1]. - Gallstones are a common complication due to chronic hemolysis. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 597-598.
Question 68: Lendrum's stain is done for:
- A. Air embolism
- B. Pulmonary embolism
- C. Fat embolism
- D. Amniotic fluid embolism (Correct Answer)
Explanation: ***Amniotic fluid embolism*** - **Lendrum's stain** (MSB - Martius Scarlet Blue) is specifically used to identify **fibrin**, **mucin**, and **squamous cells** in the pulmonary vasculature, which are characteristic findings in amniotic fluid embolism. [1] - This stain excellently demonstrates **fibrin** (stains red) and helps visualize components of amniotic fluid that embolize to the mother's lungs, leading to a severe, often fatal, obstetric emergency. [1] - Lendrum's method is particularly valuable in forensic pathology and autopsy diagnosis of this condition. *Air embolism* - Air embolism diagnosis relies on identifying **air bubbles** in the cardiovascular system, often confirmed by imaging studies or direct visualization during autopsy. [1] - Special stains are not typically used for direct detection of air in tissue sections. *Pulmonary embolism* - Pulmonary embolism, typically caused by a **blood clot**, is diagnosed by identifying **fibrin** and **red blood cells** within pulmonary arteries, often with stains like hematoxylin and eosin (H&E). [1] - While Lendrum's stain can demonstrate fibrin, it is specifically employed when amniotic fluid embolism is suspected, not for routine thromboembolic disease. *Fat embolism* - **Fat embolism** is diagnosed by demonstrating **fat globules** in the pulmonary microvasculature using **fat stains** like **Oil Red O** or **Sudan Black**, usually on frozen sections. - Lendrum's stain does not specifically highlight fat emboli. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Respiratory Tract Disease, pp. 322-324.
Question 69: Rokitansky protuberances are seen in -
- A. Papillary carcinoma
- B. Epidermoid cyst
- C. Teratoma (Correct Answer)
- D. Mucinous carcinoma
Explanation: ***Teratoma*** - **Rokitansky protuberance** (mural nodule or dermoid plug) is a raised solid area found within a **mature cystic teratoma**, particularly in the ovary [1]. - It often contains various tissues derived from the three germ layers such as **hair**, **sebaceous glands**, bone, and teeth [3]. *Papillary carcinoma* - Characterized by **papillary projections** formed by tumor cells, often seen in thyroid, kidney, or ovary. - While it can have protuberances, these are **composed of malignant cells** and lack the diverse tissue components of a Rokitansky protuberance. *Epidermoid cyst* - A benign cyst lined by **stratified squamous epithelium** and filled with keratin debris, typically located in the skin or skull. - These cysts do not form internal protuberances with heterogeneous tissue types like those seen in teratomas. *Mucinous carcinoma* - A malignant tumor characterized by the production of **mucin**, often affecting the ovary, colon, or breast [2]. - Lesions are typically filled with mucinous material or present as mucinous masses, and do not contain the specific solid Rokitansky protuberance. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Female Genital Tract, p. 1034. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Female Genital Tract, pp. 1033-1034. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Female Genital Tract Disease, pp. 480-481.