Oncology Practice Questions

Q: The likely diagnosis in a child with limb pain and pancytopenia is?

Acute lymphocytic leukaemia. **Explanation:** The combination of **limb pain** and **pancytopenia** in a child is a classic presentation of **Acute Lymphocytic Leukaemia (ALL)**. 1. **Why ALL is correct:** In pediatric ALL, the bone marrow is infiltrated by malignant lymphoblasts (myelophthisis), leading to the failure of normal hematopoiesis, which manifests as **pancytopenia** (anemia, leukopenia, and thrombocytopenia). The **limb pain** (often bone or joint pain) occurs due to the expansion of the marrow cavity by leukemic cells or direct subperiosteal infiltration. Bone pain is a distinguishing feature that often leads to a misdiagnosis of orthopedic or rheumatologic conditions. 2. **Why other options are incorrect:** * **Aplastic Anaemia:** While it presents with pancytopenia, it typically does **not** cause bone or limb pain, as the marrow is hypocellular (empty) rather than infiltrated. * **Rheumatic Fever:** Presents with migratory polyarthritis (joint pain), but it is an inflammatory condition and does not cause pancytopenia. * **Rheumatoid Arthritis (JIA):** Causes chronic joint pain and swelling. While it may show anemia of chronic disease or leukocytosis, it does not present with true pancytopenia. **Clinical Pearls for NEET-PG:** * **Most common** childhood malignancy: ALL. * **Peak age:** 2–5 years. * **Initial Investigation:** Peripheral smear (may show blasts). * **Confirmatory Investigation:** Bone marrow aspiration (>20% blasts). * **Prognostic Marker:** Hyperdiploidy and t(12;21) carry a good prognosis; hypodiploidy and t(9;22) carry a poor prognosis. * **Note:** If a child has "growing pains" that occur at night or are associated with abnormal blood counts, always rule out leukemia.

Q: Paraneoplastic opsoclonus myoclonus syndrome is most commonly associated with which malignancy in children?

Neuroblastoma. **Explanation:** **Opsoclonus-Myoclonus Syndrome (OMS)**, also known as "Dancing Eyes-Dancing Feet Syndrome," is a rare neurological disorder characterized by rapid, involuntary, multivectorial eye movements (opsoclonus), brief muscle jerks (myoclonus), and cerebellar ataxia. **Why Neuroblastoma is the Correct Answer:** In the pediatric population, OMS is most commonly a **paraneoplastic syndrome** associated with **Neuroblastoma**. It occurs in approximately 2–3% of neuroblastoma cases. The underlying mechanism is immune-mediated; the body produces antibodies against the tumor cells that cross-react with cerebellar and brainstem neurons. Interestingly, neuroblastomas associated with OMS are typically low-stage (localized), have favorable biology (non-amplified N-myc), and carry a better oncological prognosis, although neurological sequelae may persist. **Why Other Options are Incorrect:** * **Hepatoblastoma & Hepatocellular Carcinoma:** These are primary liver tumors. While they can cause paraneoplastic syndromes (like precocious puberty due to hCG secretion or thrombocytosis), they are not associated with OMS. * **Lymphoma:** While lymphomas can cause various paraneoplastic neurological syndromes in adults (like limbic encephalitis), they are not the primary association for OMS in children. **NEET-PG High-Yield Pearls:** * **Investigation of Choice:** If a child presents with OMS, the immediate next step is a workup for Neuroblastoma (CT/MRI of the abdomen/chest and urinary VMA/HVA levels). * **Prognosis:** "OMS = Better survival, but poor functional outcome" (due to long-term developmental and behavioral issues). * **Adult Association:** In adults, OMS is most commonly associated with **Small Cell Lung Cancer (SCLC)** or Breast Cancer.

Q: Which of the following statements regarding a medulloblastoma in children is true?

It is mostly infratentorial.. **Explanation:** Medulloblastoma is a highly malignant (WHO Grade 4) primitive neuroectodermal tumor and is the **most common malignant brain tumor in children**. **1. Why Option A is Correct:** Medulloblastomas characteristically arise from the **roof of the fourth ventricle** (vermis of the cerebellum). Since the cerebellum and fourth ventricle are located below the tentorium cerebelli, the tumor is **infratentorial**. In children, approximately 60-70% of all primary brain tumors are infratentorial, with medulloblastoma being a classic example. **2. Why the other options are Incorrect:** * **Option B & D:** Because these tumors arise in the posterior fossa, they frequently compress the fourth ventricle. This leads to obstructive **hydrocephalus** and increased intracranial pressure (ICP). Consequently, **papilledema** (a sign of raised ICP) is a very common clinical finding, not rare. * **Option C:** While it is the most common *malignant* brain tumor, the most common brain tumor overall in children is the **Pilocytic Astrocytoma** (which is typically benign/Grade 1). **High-Yield Clinical Pearls for NEET-PG:** * **Homer-Wright Rosettes:** A classic histopathological finding (pseudorosettes). * **Drop Metastasis:** Medulloblastoma has a high propensity to spread via CSF; therefore, imaging of the entire craniospinal axis is mandatory. * **Clinical Presentation:** Presents with truncal ataxia (due to vermis involvement) and signs of raised ICP (morning headaches, vomiting). * **Genetic Subtypes:** WNT (best prognosis), SHH, Group 3 (worst prognosis), and Group 4.

Q: What is the most common posterior fossa brain tumor in children?

Pilocytic astrocytoma. **Explanation:** The correct answer is **Pilocytic Astrocytoma**. While many older textbooks previously cited medulloblastoma as the most common, current epidemiological data and recent editions of standard radiology and neurosurgery texts (like Bailey's and Nelson's) confirm that **Juvenile Pilocytic Astrocytoma (JPA)** is the most common pediatric posterior fossa tumor and the most common primary pediatric brain tumor overall. **Why Pilocytic Astrocytoma is correct:** It is a WHO Grade I tumor, typically arising in the cerebellum. On imaging, it classically presents as a **large cystic lesion with a brightly enhancing mural nodule**. It has a relatively benign course and a favorable prognosis compared to other brain tumors. **Analysis of Incorrect Options:** * **Medulloblastoma:** This is the most common **malignant** (WHO Grade IV) brain tumor in children. It typically arises from the roof of the 4th ventricle (vermis) and shows a "drop metastasis" pattern via CSF. * **Hemangioblastoma:** While this is a common primary intra-axial tumor of the posterior fossa in **adults**, it is rare in children unless associated with Von Hippel-Lindau (VHL) syndrome. * **Occipital fossa tumor:** This is a general anatomical description rather than a specific pathological diagnosis. **High-Yield Clinical Pearls for NEET-PG:** * **Most common posterior fossa tumor:** Pilocytic Astrocytoma. * **Most common malignant CNS tumor in children:** Medulloblastoma. * **Most common supratentorial tumor in children:** Craniopharyngioma. * **Imaging Hallmark (JPA):** Cyst with an enhancing mural nodule. * **Imaging Hallmark (Medulloblastoma):** Hyperdense mass on CT (due to high cellularity) filling the 4th ventricle.

Q: Which among the following is the most common tumor associated with neurofibromatosis in children?

Juvenile myelomonocytic leukemia. **Explanation:** **Neurofibromatosis Type 1 (NF1)** is caused by a mutation in the *NF1* gene on chromosome 17, which encodes **neurofibromin**. This protein acts as a tumor suppressor by functioning as a GTPase-activating protein (GAP) that negatively regulates the **RAS signaling pathway**. **1. Why Juvenile Myelomonocytic Leukemia (JMML) is correct:** In NF1, the loss of neurofibromin leads to constitutive activation of RAS. This biochemical defect is the hallmark of JMML, a rare and aggressive clonal myeloproliferative disorder of childhood. Children with NF1 have a **200 to 500-fold increased risk** of developing JMML compared to the general population. It is the most characteristic and strongly associated hematologic malignancy in this patient group. **2. Why the other options are incorrect:** * **Acute Lymphoblastic Leukemia (ALL):** While ALL is the most common childhood leukemia overall, it does not have a specific syndromic association with NF1. * **Acute Monocytic Leukemia (AML-M5) & Acute Myeloid Leukemia (AML):** Although children with NF1 have a slightly higher risk of developing various myeloid malignancies, the association is not as specific or statistically significant as the link with JMML. **Clinical Pearls for NEET-PG:** * **Diagnostic Triad of JMML:** Splenomegaly, lymphadenopathy, and skin rashes (often resembling xanthomas). * **Laboratory Hallmark:** Elevated fetal hemoglobin (HbF) for age and hypersensitivity of myeloid progenitors to Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF). * **Other NF1-associated tumors:** Optic pathway gliomas (most common CNS tumor), Pheochromocytoma, and Malignant Peripheral Nerve Sheath Tumors (MPNST). * **Genetics:** NF1 is Autosomal Dominant; 50% of cases are *de novo* mutations.

Q: What is the most common tumor of the lumbar region in children?

Neuroblastoma. **Explanation:** **Neuroblastoma** is the most common extracranial solid tumor of childhood and the most common tumor found in the **lumbar/retroperitoneal region** in children. It originates from primordial neural crest cells of the sympathetic nervous system. Approximately 65% of neuroblastomas arise in the abdomen, with the adrenal medulla being the most frequent site (40%), followed by the lumbar sympathetic chain. These tumors often present as a firm, irregular, and nodular mass that **crosses the midline**, a key distinguishing feature from Wilms' tumor. **Analysis of Incorrect Options:** * **Dermoid Cyst:** While these can occur in the lumbosacral region (often associated with spinal dysraphism), they are benign congenital anomalies rather than the most common solid neoplastic tumors of this region. * **Wilms' Tumor (Nephroblastoma):** This is the most common primary renal tumor in children. However, it typically presents as a smooth, lateralized flank mass that **does not cross the midline**. Statistically, neuroblastoma is more common in the retroperitoneal space overall. * **Mesenteric Cyst:** These are rare intra-abdominal cystic lesions. They are usually mobile and located within the mesentery of the bowel, not primarily in the lumbar/retroperitoneal space. **High-Yield Clinical Pearls for NEET-PG:** * **Age Factor:** Neuroblastoma is most common in infants and toddlers (median age 2 years), whereas Wilms' tumor peaks slightly later (3–4 years). * **Diagnostic Marker:** Elevated urinary catecholamines (VMA and HVA) are found in 90% of neuroblastoma cases. * **Radiology:** Calcification is common in Neuroblastoma (85% on CT) but rare in Wilms' tumor. * **Opsoclonus-Myoclonus Syndrome:** A classic paraneoplastic syndrome associated with neuroblastoma ("dancing eyes, dancing feet").

Q: All are true about Juvenile CML except?

Presents with anemia, low HbF, leucocytosis. **Explanation:** Juvenile Myelomonocytic Leukemia (JMML), formerly known as Juvenile CML, is a rare and aggressive clonal hematopoietic stem cell disorder of childhood. It is distinct from adult-type Chronic Myeloid Leukemia (CML). **Why Option C is the correct answer (The False Statement):** In JMML, there is a characteristic **elevation of Hemoglobin F (HbF)**, which is often disproportionately high for the child's age. This occurs because the malignant clone exhibits "fetal-like" erythropoiesis. Therefore, the statement "low HbF" is incorrect. Patients typically present with anemia, thrombocytopenia, and significant leukocytosis with monocytosis (>1000/μL). **Analysis of other options:** * **Option A:** Unlike adult CML, JMML is **Philadelphia chromosome (t[9;22]) negative**. It is driven by mutations in the RAS pathway (PTPN11, NF1, NRAS, KRAS, or CBL). * **Option B:** There is a strong clinical association with **Neurofibromatosis Type 1 (NF1)**. Children with NF1 have a 200- to 500-fold increased risk of developing JMML. * **Option C:** JMML is primarily a disease of early childhood, with approximately 75% of cases occurring in children **less than 2 years of age**. **High-Yield Clinical Pearls for NEET-PG:** * **Hallmark finding:** Absolute monocytosis (>1000/μL) and hypersensitivity of myeloid progenitors to Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) in vitro. * **Physical Exam:** Massive hepatosplenomegaly and lymphadenopathy are common. * **Skin findings:** Xanthomas and café-au-lait spots (especially if associated with NF1). * **Treatment:** Hematopoietic stem cell transplant (HSCT) is the only curative treatment.

Q: Which of the following is NOT a common childhood tumor?

Pleomorphic rhabdomyosarcoma. **Explanation:** The correct answer is **Pleomorphic rhabdomyosarcoma** because of its distinct age-related epidemiology. Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, but it is divided into histological subtypes that occur in different age groups. 1. **Why Option D is correct:** **Pleomorphic RMS** is a subtype that occurs almost exclusively in **adults** (usually >45 years old). In contrast, the subtypes common in children are **Embryonal RMS** (most common overall, seen in younger children) and **Alveolar RMS** (seen in adolescents). 2. **Why Options A, B, and C are incorrect:** * **Wilms' tumor (Nephroblastoma):** The most common primary renal tumor of childhood, typically presenting between ages 2–5. * **Neuroblastoma:** The most common extracranial solid tumor of childhood, arising from the sympathetic nervous system (adrenal medulla or paraspinal ganglia). * **Retinoblastoma:** The most common intraocular tumor in children, often presenting with leukocoria (white pupillary reflex). **Clinical Pearls for NEET-PG:** * **Most common childhood cancer:** Leukemia (specifically ALL). * **Most common solid tumor:** CNS tumors. * **Most common extracranial solid tumor:** Neuroblastoma. * **Small Round Blue Cell Tumors:** This is a high-yield differential for childhood tumors, including Neuroblastoma, Wilms' tumor, Ewing’s sarcoma, and Embryonal Rhabdomyosarcoma. * **RMS Subtype Locations:** Embryonal RMS often occurs in the head/neck or genitourinary tract; Alveolar RMS is more common in the extremities.

Q: Which of the following is a poor prognostic factor in a child with ALL?

Translocations t(9;22), t(4;11), t(1;19). In Acute Lymphoblastic Leukemia (ALL), prognosis is determined by age, initial white cell count, and specific cytogenetic abnormalities. **Why Option C is Correct:** Cytogenetics is the most significant independent prognostic factor in ALL. * **t(9;22) (Philadelphia chromosome):** Associated with the BCR-ABL1 fusion gene; it carries a very poor prognosis and requires TKI (Imatinib) therapy. * **t(4;11):** Involves the KMT2A (MLL) gene rearrangement, typically seen in infant ALL, and is associated with a high risk of relapse. * **t(1;19):** Involves the E2A-PBX1 fusion; while outcomes have improved with intensive therapy, it was historically considered a poor prognostic marker. **Why Other Options are Incorrect:** * **Age 2-8 years (Option A):** This is the **favorable** age group. Age 10 years (adolescents) are considered poor prognostic factors. * **TLC 50,000/µL is a high-risk feature. * **Absent blasts (Option D):** The presence or absence of blasts in the peripheral smear does not define prognosis as much as the **Minimal Residual Disease (MRD)** status after the induction phase of chemotherapy. **High-Yield Clinical Pearls for NEET-PG:** * **Best Prognosis:** Hyperdiploidy (>50 chromosomes) and t(12;21) (ETV6-RUNX1). * **Worst Prognosis:** Hypodiploidy (<44 chromosomes) and t(9;22). * **Immunophenotype:** Early Pre-B cell ALL has a better prognosis than T-cell ALL or mature B-cell (Burkitt) ALL. * **Most Important Factor:** The most important predictor of treatment outcome today is the **response to initial therapy (MRD status)** at the end of induction (Day 28).

Question 1

The likely diagnosis in a child with limb pain and pancytopenia is?

Accepted Answer

Acute lymphocytic leukaemia

Answer

Aplastic anaemia

Answer

Rheumatic fever

Answer

Rheumatoid arthritis

Question 2

Paraneoplastic opsoclonus myoclonus syndrome is most commonly associated with which malignancy in children?

Accepted Answer

Neuroblastoma

Answer

Hepatoblastoma

Answer

Hepatocellular carcinoma

Answer

Lymphoma

Question 3

Which of the following statements regarding a medulloblastoma in children is true?

Accepted Answer

It is mostly infratentorial.

Answer

Papilledema is rare.

Answer

It is the most common tumor in children.

Answer

Hydrocephalus is rare.

Question 4

What is the most common posterior fossa brain tumor in children?

Accepted Answer

Pilocytic astrocytoma

Answer

Medulloblastoma

Answer

Hemangioblastoma

Answer

Occipital fossa tumor

Question 5

Which among the following is the most common tumor associated with neurofibromatosis in children?

Accepted Answer

Juvenile myelomonocytic leukemia

Answer

Acute lymphoblastic leukemia

Answer

Acute monocytic leukemia

Answer

Acute myeloid leukemia

Question 6

Which one is the best prognostic factor for ALL?

Accepted Answer

Response to treatment

Answer

Hyperdiploidy

Answer

Organomegaly

Answer

TLC more than 50,000/mL

Question 7

What is the most common tumor of the lumbar region in children?

Accepted Answer

Neuroblastoma

Answer

Dermoid cyst

Answer

Wilm's tumor

Answer

Mesenteric cyst

Question 8

All are true about Juvenile CML except?

Accepted Answer

Presents with anemia, low HbF, leucocytosis

Answer

Philadelphia chromosome is absent

Answer

Associated with Neurofibromatosis-1

Answer

Most common in less than 2 years of age

Question 9

Which of the following is NOT a common childhood tumor?

Accepted Answer

Pleomorphic rhabdomyosarcoma

Answer

Wilms' tumor

Answer

Neuroblastoma

Answer

Retinoblastoma

Question 10

Which of the following is a poor prognostic factor in a child with ALL?

Accepted Answer

Translocations t(9;22), t(4;11), t(1;19)

Answer

Age 2-8 years

Answer

Total leukocyte count < 50,000

Answer

Absent blasts in peripheral smear

Oncology — MCQs

Oncology — MCQs

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