Oncology — MCQs
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What is the most common cause of cranial irradiation in children?
What is the definition of trilateral retinoblastoma?
What is the most common malignancy in children?
What is the most common gastrointestinal malignancy in children?
A 7 – year old boy presented with abdominal pain, vomiting, oliguria, and periorbital puffiness following chemotherapy. Investigations reveal hyperuricemia, raised creatinine levels, and hyperkalemia. What is the next best step in the management of this condition ?
A 6-year-old child presents with an abdominal mass, fever, bone pain, and inferior vena cava (IVC) thrombosis. What is the most likely diagnosis?
Among the following, which pulmonary tumor is most likely to occur in children?
On USG, a mass was found in the abdomen which was displacing the kidney laterally in a 1-year-old child. What is the most likely diagnosis?
Opsoclonus-myoclonus is a phenomenon seen in:
Most common site of extramedullary relapse of ALL in a 6-year-old boy is
Oncology Indian Medical PG Practice Questions and MCQs
Question 201: What is the most common cause of cranial irradiation in children?
- A. Craniopharyngioma (a brain tumor)
- B. Small Cell Lung Cancer (SCLC)
- C. Acute Lymphoblastic Leukemia (ALL) (Correct Answer)
- D. Acute Myeloid Leukemia (AML)
Explanation: ***Acute Lymphoblastic Leukemia (ALL)*** - **ALL** is the **most common childhood cancer** and remains the most common indication for cranial irradiation in children when it is needed - While modern protocols have **reduced** the use of cranial irradiation due to long-term neurocognitive side effects, it is still indicated in: - **High-risk ALL** (typically 12-18 Gy for CNS prophylaxis) - **CNS relapse** or CNS involvement at diagnosis - **T-cell ALL** with high-risk features - The shift toward **intrathecal chemotherapy** has reduced but not eliminated the need for cranial irradiation in ALL *Craniopharyngioma (a brain tumor)* - Craniopharyngioma is a **relatively rare** pediatric brain tumor (1-2% of all pediatric brain tumors) - Treatment is primarily **surgical resection** with radiation as **adjuvant therapy** in selected cases - Due to its rarity compared to ALL, it is not the most common cause of cranial irradiation in children *Small Cell Lung Cancer (SCLC)* - **SCLC** is primarily a disease of **adult heavy smokers** and is **exceedingly rare** in children - This is essentially not a pediatric disease and would not be a common indication for cranial irradiation in the pediatric population *Acute Myeloid Leukemia (AML)* - **AML** is less common than ALL in children - **CNS prophylaxis** is less frequently required in AML compared to ALL - Treatment primarily involves **intensive chemotherapy** with intrathecal therapy for CNS prophylaxis when needed
Question 202: What is the definition of trilateral retinoblastoma?
- A. Bilateral retinoblastoma with medulloblastoma
- B. Bilateral retinoblastoma with pineoblastoma (Correct Answer)
- C. Bilateral retinoblastoma with neuroblastoma
- D. Bilateral retinoblastoma with ependymoma
Explanation: ***Bilateral retinoblastoma with pineoblastoma*** - **Trilateral retinoblastoma** is a rare and aggressive form of retinoblastoma that occurs when a bilateral retinoblastoma is accompanied by a **pineoblastoma** (a primitive neuroectodermal tumor of the pineal gland). - This condition is typically associated with **hereditary retinoblastoma**, caused by germline mutations in the *RB1* gene. *Bilateral retinoblastoma with medulloblastoma* - While medulloblastoma is another type of **primitive neuroectodermal tumor (PNET)**, the specific combination for trilateral retinoblastoma is with a **pineoblastoma**, not medulloblastoma. - Medulloblastoma is a common pediatric brain tumor, but its co-occurrence with retinoblastoma does not define trilateral retinoblastoma. *Bilateral retinoblastoma with neuroblastoma* - **Neuroblastoma** is a distinct type of childhood cancer that originates from **neural crest cells**, often found in the adrenal glands or sympathetic nervous system. - This combination is not recognized as **trilateral retinoblastoma**, which specifically involves a pineal region tumor. *Bilateral retinoblastoma with ependymoma* - **Ependymoma** is a brain tumor that arises from the **ependymal lining** of the ventricles and spinal cord. - This particular association is not the definition of **trilateral retinoblastoma**, which is specifically linked to a tumor of the pineal gland.
Question 203: What is the most common malignancy in children?
- A. Acute Lymphoblastic Leukemia (Correct Answer)
- B. Acute Myeloid Leukemia
- C. Neuroblastoma
- D. Wilms tumor
Explanation: ***Acute Lymphoblastic Leukemia*** - **Acute Lymphoblastic Leukemia (ALL)** is the **most common childhood malignancy**, accounting for approximately 25% of all pediatric cancers. - It arises from the uncontrolled proliferation of immature lymphoid cells (lymphoblasts) in the bone marrow and often presents with symptoms like **fatigue**, **fever**, **bleeding**, and **bone pain**. *Acute Myeloid Leukemia* - While **Acute Myeloid Leukemia (AML)** is also a common leukemia in children, it is **less frequent than ALL**, accounting for about 20% of pediatric leukemias. - AML involves the abnormal proliferation of immature myeloid cells and typically presents similar symptoms to ALL, but it tends to affect a **slightly older age group** within childhood. *Neuroblastoma* - **Neuroblastoma** is a common **solid tumor** of childhood, originating from immature nerve cells in the sympathetic nervous system. - It is the **most common extracranial solid tumor** in children but occurs less frequently than ALL overall. *Wilms tumor* - **Wilms tumor**, also known as nephroblastoma, is the **most common primary malignant renal tumor** in children. - Although it is a significant childhood cancer, its incidence is lower than that of ALL.
Question 204: What is the most common gastrointestinal malignancy in children?
- A. Adenocarcinoma
- B. Lymphoma (Correct Answer)
- C. Sarcoma
- D. Carcinoid
Explanation: ***Lymphoma*** - **Non-Hodgkin lymphoma (NHL)** is the most common gastrointestinal malignancy in children, with **Burkitt lymphoma** being the predominant subtype. - Typically presents as abdominal masses, intussusception (especially ileocolic), or bowel obstruction. - GI involvement in childhood cancers is most frequently seen with **lymphoproliferative disorders**. *Adenocarcinoma* - **Adenocarcinoma of the gastrointestinal tract** is extremely rare in children and is typically a disease of older adults. - Originates from **glandular cells** and usually requires prolonged exposure to risk factors not present in childhood. *Sarcoma* - While sarcomas can occur in children, they are more common in soft tissues and bone rather than as primary **gastrointestinal malignancies**. - **Gastrointestinal stromal tumors (GISTs)** are a type of sarcoma that can rarely affect the GI tract in children, but are much less common than lymphoma. *Carcinoid* - **Carcinoid tumors** (neuroendocrine tumors) are very rare in children as a primary GI malignancy. - These are typically **slow-growing tumors** more common in adults, often found incidentally.
Question 205: A 7 – year old boy presented with abdominal pain, vomiting, oliguria, and periorbital puffiness following chemotherapy. Investigations reveal hyperuricemia, raised creatinine levels, and hyperkalemia. What is the next best step in the management of this condition ?
- A. Hydration (Correct Answer)
- B. Probenecid
- C. Allopurinol
- D. Rasburicase
Explanation: ***Hydration*** - This patient presents with **tumor lysis syndrome (TLS)**, characterized by rapid tumor cell breakdown releasing intracellular contents (uric acid, potassium, phosphate) following chemotherapy. - **Aggressive intravenous hydration** is the **first-line and most critical initial step** in TLS management, aiming to maintain urine output at 2-3 mL/kg/hour to prevent uric acid crystal precipitation in renal tubules. - Even with oliguria present, optimizing intravascular volume and renal perfusion is essential before other interventions can be effective - without adequate hydration, rasburicase-generated allantoin cannot be excreted. - **Hydration forms the foundation** upon which all other TLS therapies depend, making it the priority "next best step." *Probenecid* - **Probenecid** is a uricosuric agent that increases renal uric acid excretion by blocking tubular reabsorption. - It is **contraindicated in tumor lysis syndrome** as it increases uric acid concentration in renal tubules, potentially worsening uric acid nephropathy and crystal formation. *Allopurinol* - **Allopurinol** is a xanthine oxidase inhibitor that prevents new uric acid formation by blocking purine metabolism. - While valuable for **prophylaxis** in high-risk patients before chemotherapy, it **does not reduce existing hyperuricemia** in established TLS. - Less effective than rasburicase for treating active, symptomatic hyperuricemia. *Rasburicase* - **Rasburicase** is a recombinant urate oxidase that rapidly converts uric acid to allantoin (5-10 times more soluble). - Highly effective for **treating established hyperuricemia** in TLS and often used in severe cases. - However, as the "next best step," **hydration must be established first** to ensure adequate renal perfusion and allow excretion of metabolites - rasburicase is typically administered **after or concurrent with** hydration initiation. - In clinical practice, both are often started together, but hydration is the foundational intervention.
Question 206: A 6-year-old child presents with an abdominal mass, fever, bone pain, and inferior vena cava (IVC) thrombosis. What is the most likely diagnosis?
- A. Wilm's tumour
- B. Neuroblastoma (Correct Answer)
- C. Langerhans cell Histiocytosis
- D. Gastric lymphoma
Explanation: ***Neuroblastoma*** - **Neuroblastoma** is the most likely diagnosis given the combination of **abdominal mass** (typically from adrenal/retroperitoneal origin), **bone pain from metastases** (bone is the most common site of metastasis in neuroblastoma), and systemic symptoms. - **Bone pain and bone metastases** are highly characteristic of neuroblastoma and occur in approximately 50-60% of cases at presentation. - **Inferior vena cava thrombosis** can occur due to tumor compression or direct extension, and **fever** is a common paraneoplastic symptom. - Peak age: 2-5 years, but can occur at 6 years. *Wilm's tumour* - **Wilm's tumor** typically presents as a unilateral, smooth, firm abdominal mass and can extend into the IVC via the renal vein (in 4-10% of cases). - **KEY DIFFERENTIATOR:** Bone metastases are **extremely rare** in Wilm's tumor (<2% of cases), making **bone pain** a critical feature that strongly favors neuroblastoma over Wilm's tumor. - Wilm's tumor more commonly metastasizes to lungs and liver, not bone. *Langerhans cell Histiocytosis* - **Langerhans cell Histiocytosis** can cause **bone lesions** (lytic skull lesions are classic) and **fever**, but an **abdominal mass** and **IVC thrombosis** are not characteristic presentations. - This condition typically presents with skin rash, lymphadenopathy, diabetes insipidus, or isolated bone lesions—not a primary abdominal mass. *Gastric lymphoma* - **Gastric lymphoma** is rare in young children and primarily affects the stomach with abdominal pain, weight loss, and sometimes a palpable mass. - Does not typically cause widespread **bone pain** or **IVC thrombosis** as primary presenting features. - More common in adolescents and adults rather than young children.
Question 207: Among the following, which pulmonary tumor is most likely to occur in children?
- A. Carcinoid (Correct Answer)
- B. Small cell carcinoma
- C. Squamous cell carcinoma
- D. Adenocarcinoma
Explanation: ***Carcinoid*** - **Bronchial carcinoid tumors** are the most common primary lung tumors found in children and adolescents, accounting for a significant percentage of pediatric pulmonary neoplasms. - These tumors arise from **neuroendocrine cells** and generally have a low-grade malignant potential. *Small cell carcinoma* - **Small cell lung carcinoma (SCLC)** is strongly associated with smoking and is highly aggressive, almost exclusively occurring in adults. - It is exceedingly rare in children, making it an unlikely diagnosis in this age group. *Adenocarcinoma* - **Adenocarcinoma** is the most common histological type of lung cancer in adults who do not smoke but is still extremely rare in children. - Although it can occur in non-smokers and younger adults, it is not the most likely primary pulmonary tumor in the pediatric population. *Squamous cell carcinoma* - **Squamous cell carcinoma** is primarily linked to extensive smoking history and is predominantly seen in older adult patients. - It is virtually unheard of in children, making it a highly improbable diagnosis.
Question 208: On USG, a mass was found in the abdomen which was displacing the kidney laterally in a 1-year-old child. What is the most likely diagnosis?
- A. Neuroblastoma (Correct Answer)
- B. Wilms' tumor
- C. Renal cell carcinoma
- D. All of the options
Explanation: ***Neuroblastoma*** - A retroperitoneal mass displacing the kidney laterally in an infant is highly characteristic of **neuroblastoma**, which originates from neural crest cells in the adrenal gland or sympathetic ganglia. - The key finding is **extrarenal origin** - the mass pushes the kidney aside rather than arising from within it. - Most common extrarenal abdominal mass in children under 2 years. *Wilms' tumor* - This is an **intrarenal mass** that originates within the kidney parenchyma. - Wilms' tumor **expands and distorts the kidney** rather than displacing it laterally from outside. - Most common renal tumor in children (peak age 3-4 years), presenting with abdominal mass, hematuria, and hypertension. *Renal cell carcinoma* - Exceedingly **rare in a 1-year-old child** - primarily an adult malignancy (typically >40 years). - Would be an intrarenal mass, not an extrarenal mass displacing the kidney laterally. *All of the options* - Incorrect because the specific imaging finding of **lateral kidney displacement** indicates an extrarenal origin, which is pathognomonic for neuroblastoma, not the intrarenal tumors listed.
Question 209: Opsoclonus-myoclonus is a phenomenon seen in:
- A. Wilms' tumor
- B. Meningioma
- C. Cortical tuberculoma
- D. Neuroblastoma (Correct Answer)
Explanation: ***Neuroblastoma*** - **Opsoclonus-myoclonus syndrome (OMS)** is a rare paraneoplastic neurological disorder primarily associated with childhood neuroblastoma. - It is characterized by rapid, irregular eye movements (**opsoclonus**), brief, involuntary muscle jerks (**myoclonus**), ataxia, and irritability. *Wilm's tumor* - Wilms' tumor (nephroblastoma) is a kidney tumor of childhood and is not typically associated with opsoclonus-myoclonus syndrome. - While it is also a pediatric cancer, its paraneoplastic manifestations are different and do not include OMS. *Meningioma* - Meningiomas are typically slow-growing tumors arising from the meninges in adults, and are not associated with opsoclonus-myoclonus. - Paraneoplastic syndromes are rare with meningiomas, and OMS is not one of them. *Cortical tuberculoma* - A cortical tuberculoma is a granulomatous lesion in the brain caused by Mycobacterium tuberculosis, often seen in individuals with tuberculosis. - While it can cause neurological symptoms like seizures, headaches, and focal deficits, it does not cause opsoclonus-myoclonus syndrome.
Question 210: Most common site of extramedullary relapse of ALL in a 6-year-old boy is
- A. Testes
- B. Liver
- C. CNS (Central Nervous System) (Correct Answer)
- D. Lung
Explanation: ***CNS (Central Nervous System)*** - The **central nervous system** is the **most common site of extramedullary relapse** in pediatric acute lymphoblastic leukemia (ALL), accounting for the majority of extramedullary relapses. - CNS is an immunologically privileged sanctuary site where chemotherapy penetration is limited due to the blood-brain barrier. - CNS relapse presents with symptoms like headache, vomiting, cranial nerve palsies, or signs of increased intracranial pressure and requires intrathecal chemotherapy and cranial irradiation. - Prophylactic CNS therapy is a standard component of ALL treatment protocols to prevent CNS relapse. *Testes* - **Testes** are the **second most common** site of extramedullary relapse and the most common **solid organ** site in boys with ALL. - Like the CNS, testes are immunologically privileged sites with limited chemotherapy penetration. - Testicular relapse presents as painless testicular enlargement (unilateral or bilateral) and requires testicular radiation plus systemic therapy intensification. *Liver* - While **hepatic infiltration** can occur in ALL, the liver is not a common site for **isolated extramedullary relapse**. - Hepatic involvement typically indicates widespread systemic disease rather than a primary relapse site. *Lung* - **Pulmonary involvement** in ALL is rare as an isolated extramedullary relapse site. - Lung findings in ALL patients are more commonly due to infection, leukostasis in hyperleukocytosis, or disseminated disease.
Practice by Chapter
Leukemias
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Lymphomas
Practice Questions
CNS Tumors
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Neuroblastoma
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Wilms Tumor
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Rhabdomyosarcoma
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Bone Tumors
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Retinoblastoma
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Histiocytosis Syndromes
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Principles of Pediatric Chemotherapy
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Hematopoietic Stem Cell Transplantation
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Late Effects of Cancer Treatment
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