Oncology — MCQs

Oncology Indian Medical PG Practice Questions and MCQs

Question 131: What is the most common tumor of the lumbar region in children?

A. Dermoid cyst
B. Neuroblastoma (Correct Answer)
C. Wilm's tumor
D. Mesenteric cyst

Explanation: **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").

Question 132: All are true about Juvenile CML except?

A. Philadelphia chromosome is absent
B. Associated with Neurofibromatosis-1
C. Presents with anemia, low HbF, leucocytosis (Correct Answer)
D. Most common in less than 2 years of age

Explanation: **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.

Question 133: Which of the following is NOT a common childhood tumor?

A. Wilms' tumor
B. Neuroblastoma
C. Retinoblastoma
D. Pleomorphic rhabdomyosarcoma (Correct Answer)

Explanation: **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.

Question 134: Which of the following is a poor prognostic factor in a child with ALL?

A. Age 2-8 years
B. Total leukocyte count < 50,000
C. Translocations t(9;22), t(4;11), t(1;19) (Correct Answer)
D. Absent blasts in peripheral smear

Explanation: 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 <1 year (infants) or >10 years (adolescents) are considered poor prognostic factors. * **TLC < 50,000 (Option B):** A low initial Total Leukocyte Count (especially <50,000/µL in B-ALL) is a **good** prognostic indicator. A 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 135: Which is the most common malignancy in children?

A. Retinoblastoma
B. Leukemia (Correct Answer)
C. Wilms tumor
D. Neuroblastoma

Explanation: **Explanation:** In pediatric oncology, the distribution of malignancies differs significantly from adults. **Leukemia** is the most common malignancy in children, accounting for approximately **30% of all childhood cancers**. Among leukemias, **Acute Lymphoblastic Leukemia (ALL)** is the most frequent subtype (75-80%), followed by Acute Myeloid Leukemia (AML). **Analysis of Options:** * **Leukemia (Correct):** It is the overall most common childhood cancer. The peak incidence occurs between 2 and 5 years of age. * **Retinoblastoma:** This is the most common **intraocular** tumor in children, but it is relatively rare compared to systemic malignancies. * **Wilms Tumor (Nephroblastoma):** This is the most common **renal** tumor in children, typically presenting as an asymptomatic abdominal mass. * **Neuroblastoma:** This is the most common **extracranial solid tumor** in childhood and the most common malignancy in **infants** (under 1 year of age). **High-Yield Clinical Pearls for NEET-PG:** * **Most common childhood cancer:** Leukemia (specifically ALL). * **Most common solid tumor:** CNS Tumors (Brain tumors). * **Most common extracranial solid tumor:** Neuroblastoma. * **Most common abdominal mass in children:** Hydronephrosis (Benign); Wilms Tumor (Malignant). * **Most common neonatal/infantile malignancy:** Neuroblastoma. * **Most common soft tissue sarcoma:** Rhabdomyosarcoma. * **Most common primary bone tumor:** Osteosarcoma (followed by Ewing sarcoma).

Question 136: A 6-year-old boy with lymphoreticular malignancy is scheduled for a cycle of chemotherapy. Which of the following investigations should be performed within the next 4 hours to diagnose tumor lysis syndrome?

A. Urea, creatinine, chloride, Ca2+, and K+
B. Urea, creatinine, phosphate, Ca2+, and K+ (Correct Answer)
C. Urea, creatinine, magnesium, Ca2+, and K+
D. Urea, creatinine, sodium, and phosphate

Explanation: **Explanation:** **Tumor Lysis Syndrome (TLS)** is an oncologic emergency caused by the rapid breakdown of malignant cells, leading to the release of intracellular contents into the bloodstream. This typically occurs in high-grade malignancies like Burkitt lymphoma or leukemias following chemotherapy. **Why Option B is Correct:** The diagnosis of TLS (specifically the **Cairo-Bishop Definition**) relies on identifying four metabolic derangements. When cells lyse, they release high concentrations of: 1. **Potassium (K+):** Leading to Hyperkalemia. 2. **Phosphate:** Leading to Hyperphosphatemia. 3. **Uric Acid:** (Metabolized from nucleic acids) leading to Hyperuricemia. 4. **Calcium (Ca2+):** Secondary **Hypocalcemia** occurs because the excess phosphate binds to calcium, forming calcium phosphate crystals. **Urea and Creatinine** are essential to monitor for Acute Kidney Injury (AKI) caused by the precipitation of uric acid and calcium phosphate in the renal tubules. **Why Other Options are Incorrect:** * **Option A & D:** Chloride and Sodium levels are not diagnostic criteria for TLS. While they are part of a routine electrolyte panel, they do not reflect the specific metabolic "burst" seen in cell lysis. * **Option C:** Magnesium is not a primary diagnostic marker for TLS. While electrolyte imbalances can occur, phosphate is the critical intracellular anion that defines the syndrome. **NEET-PG High-Yield Pearls:** * **Cairo-Bishop Criteria:** Laboratory TLS is diagnosed if two or more of the following occur within 3 days before or 7 days after chemotherapy: Uric acid >8 mg/dL, Potassium >6 mEq/L, Phosphate >4.5 mg/dL, or Calcium <7 mg/dL. * **First Sign:** Hyperkalemia is often the earliest sign. * **Management:** Aggressive hydration is the mainstay. **Rasburicase** (recombinant uric oxidase) is the drug of choice for high-risk patients, while **Allopurinol** is used for prophylaxis. * **ECG:** Always monitor for peaked T-waves due to hyperkalemia.

Question 137: Which of the following statements is false regarding Wilm's tumor?

A. Presents before the age of 5 years
B. Mostly presents as an abdominal mass
C. Spreads mostly by lymphatics (Correct Answer)
D. Responds well to treatment

Explanation: **Explanation:** Wilms tumor (Nephroblastoma) is the most common primary renal malignancy in children. The correct answer is **Option C** because Wilms tumor primarily spreads via **direct local invasion** and **hematogenous routes** (most commonly to the lungs), rather than lymphatics. While regional lymph node involvement can occur (seen in ~15% of cases), it is not the primary mode of spread. **Analysis of Options:** * **Option A (True):** The peak incidence is between **2 to 3 years** of age. Approximately 90% of cases are diagnosed before age 5, making it a classic pediatric malignancy. * **Option B (True):** The most common clinical presentation (80-90%) is an **asymptomatic, firm, smooth abdominal mass** that typically does not cross the midline (unlike Neuroblastoma). * **Option D (True):** Wilms tumor is a success story in pediatric oncology. With a multimodal approach (surgery, chemotherapy, and sometimes radiation), the overall cure rate exceeds **90%**. **High-Yield Clinical Pearls for NEET-PG:** 1. **WAGR Syndrome:** Wilms tumor, Aniridia, Genitourinary anomalies, and intellectual disability (formerly Retardation). Associated with **WT1 gene** deletion on Chromosome 11p13. 2. **Beckwith-Wiedemann Syndrome:** Macroglossia, organomegaly, and hemihypertrophy. Associated with **WT2 gene** on Chromosome 11p15. 3. **Diagnosis:** Contrast-enhanced CT (CECT) is the gold standard for staging. 4. **Prognosis:** The most important prognostic factor is **histology** (favorable vs. unfavorable/anaplastic). 5. **Management Tip:** Avoid vigorous palpation of the abdomen to prevent rupture of the tumor capsule and subsequent peritoneal seeding.

Question 138: What is the most common abdominal mass in children?

A. Hydronephrosis
B. Wilms' tumor
C. Neuroblastoma (Correct Answer)
D. Rhabdomyosarcoma

Explanation: **Explanation:** The correct answer is **Neuroblastoma**. In pediatric oncology and surgery, it is essential to distinguish between the most common abdominal *mass* and the most common abdominal *malignancy*. **1. Why Neuroblastoma is correct:** Neuroblastoma is the **most common extracranial solid tumor** of childhood and the **most common abdominal mass** overall in the pediatric population. It originates from primordial neural crest cells of the sympathetic nervous system, most frequently occurring in the adrenal medulla (approx. 40%). Clinically, it often presents as a firm, irregular, and nodular mass that **crosses the midline**, distinguishing it from other renal masses. **2. Why other options are incorrect:** * **Hydronephrosis:** While it is the most common cause of a palpable abdominal mass in **neonates** (newborns), it is not the most common cause across the entire pediatric age group. * **Wilms’ Tumor (Nephroblastoma):** This is the most common **primary renal malignancy** in children. Unlike Neuroblastoma, a Wilms' tumor is typically smooth, rarely crosses the midline, and the peak incidence is slightly later (3–4 years). * **Rhabdomyosarcoma:** This is the most common soft tissue sarcoma in children, but it typically involves the head, neck, or genitourinary tract (bladder/prostate) rather than presenting as a primary abdominal mass. **Clinical Pearls for NEET-PG:** * **Crossing the Midline:** Neuroblastoma crosses the midline; Wilms’ tumor usually does not. * **Calcification:** On CT, Neuroblastoma frequently shows stippled calcifications (85%), whereas Wilms’ tumor rarely does. * **Markers:** Elevated urinary catecholamines (VMA and HVA) are diagnostic for Neuroblastoma. * **Opsoclonus-Myoclonus Syndrome:** A high-yield paraneoplastic syndrome associated specifically with Neuroblastoma ("dancing eyes, dancing feet").

Question 139: What is the most common site of metastasis in neuroblastoma?

A. Lung
B. Liver
C. Lymph nodes (Correct Answer)
D. Vertebrae

Explanation: **Explanation:** Neuroblastoma is the most common extracranial solid tumor of childhood, arising from primordial neural crest cells. Understanding its metastatic pattern is crucial for NEET-PG. **1. Why Lymph Nodes are Correct:** In neuroblastoma, the most common route of spread is via the lymphatic system. **Regional lymph nodes** are the most frequent site of metastasis, occurring in approximately 70% of patients with disseminated disease. This is followed closely by the bone marrow and cortical bone. **2. Why the other options are incorrect:** * **Lung (A):** Unlike Wilms tumor (where the lung is the most common site), pulmonary metastasis is **rare** in neuroblastoma, occurring in less than 3% of cases. * **Liver (B):** While the liver is a common site of metastasis, particularly in **Stage 4S** (Special) neuroblastoma in infants (Pepper Syndrome), it is not the most frequent site overall across all age groups. * **Vertebrae (D):** While neuroblastoma frequently metastasizes to the **cortical bone** (especially the skull and orbit, leading to "raccoon eyes"), lymph node involvement remains statistically more prevalent than isolated vertebral metastasis. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of origin:** Adrenal medulla (followed by the retroperitoneal sympathetic chain). * **Opsoclonus-Myoclonus Syndrome:** A paraneoplastic syndrome associated with favorable prognosis neuroblastoma ("Dancing eyes, dancing feet"). * **Homer-Wright Rosettes:** The characteristic histopathological finding (pseudorosettes). * **Urinary Markers:** Elevated VMA (Vanillylmandelic acid) and HVA (Homovanillic acid). * **N-myc Amplification:** The most important poor prognostic genetic marker.

Question 140: A 5-year-old child presents with a history of fever off-and-on for the past 2 weeks, petechial spots all over the body, and increasing pallor for the past 1 month. Examination reveals splenomegaly 2 cm below the costal margin. What is the most likely diagnosis?

A. Acute leukemia (Correct Answer)
B. Idiopathic thrombocytopenic purpura
C. Hypersplenism
D. Aplastic anemia

Explanation: **Explanation:** The clinical presentation of **fever, pallor, and petechiae** represents the classic triad of **pancytopenia** (anemia, leukopenia/dysfunction, and thrombocytopenia). In a pediatric patient, this triad combined with **organomegaly** (splenomegaly) is highly suggestive of **Acute Leukemia**, most commonly Acute Lymphoblastic Leukemia (ALL). 1. **Why Acute Leukemia is correct:** The infiltration of the bone marrow by malignant blast cells leads to "marrow failure," causing anemia (pallor), thrombocytopenia (petechiae), and functional neutropenia (fever/infections). The presence of **splenomegaly** indicates extramedullary involvement, which is a hallmark of leukemia and helps differentiate it from simple marrow failure. 2. **Why other options are incorrect:** * **Idiopathic Thrombocytopenic Purpura (ITP):** Typically presents with isolated petechiae/bruising in a "well-appearing" child. It does **not** cause pallor or splenomegaly. * **Aplastic Anemia:** While it presents with pancytopenia (pallor, fever, petechiae), it is characterized by an "empty" marrow. Therefore, **splenomegaly and lymphadenopathy are characteristically absent.** * **Hypersplenism:** While it can cause cytopenias, it usually presents with a massive spleen and an underlying cause (like portal hypertension), rather than the acute febrile onset seen here. **Clinical Pearls for NEET-PG:** * **Most common childhood cancer:** Acute Lymphoblastic Leukemia (ALL). * **Peak age for ALL:** 2–5 years. * **Key differentiator:** Pancytopenia + Splenomegaly = Leukemia; Pancytopenia + No Splenomegaly = Aplastic Anemia. * **Diagnostic Gold Standard:** Bone marrow aspiration showing >20% blasts.

Practice by Chapter

Leukemias

Practice Questions

Lymphomas

Practice Questions

CNS Tumors

Practice Questions

Neuroblastoma

Practice Questions

Wilms Tumor

Practice Questions

Rhabdomyosarcoma

Practice Questions

Bone Tumors

Practice Questions

Retinoblastoma

Practice Questions

Histiocytosis Syndromes

Practice Questions

Principles of Pediatric Chemotherapy

Practice Questions

Hematopoietic Stem Cell Transplantation

Practice Questions

Late Effects of Cancer Treatment

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Oncology — MCQs

Oncology — MCQs

On this page

Practice by Chapter

Want unlimited practice?