A 4-year-old boy with Down syndrome presents with fatigue and recurrent infections. CBC shows WBC 150,000/μL with 90% myeloblasts, hemoglobin 6.5 g/dL, platelets 15,000/μL. Flow cytometry confirms acute myeloid leukemia with megakaryoblastic features (AMKL). The parents are concerned about treatment intensity given their child's baseline developmental delays and increased treatment-related toxicity risk in Down syndrome. Evaluate the treatment approach considering the unique biology and competing risks.
Q2
A 15-year-old boy presents with right distal femur pain and a palpable mass. X-ray shows a mixed lytic-sclerotic lesion with periosteal elevation creating a Codman triangle and sunburst pattern. Biopsy confirms osteosarcoma. Staging shows pulmonary micrometastases. Alkaline phosphatase is markedly elevated. The family requests consideration of alternative therapies and limb salvage options. Synthesize the treatment plan addressing oncologic outcomes and functional preservation.
Q3
A 2-year-old girl presents with a large abdominal mass, aniridia, and developmental delay. Family history reveals a sibling who died of Wilms tumor at age 3. Genetic testing shows a germline WT1 mutation. Ultrasound reveals bilateral renal masses. The parents are concerned about treatment options that preserve renal function. Evaluate the optimal management strategy considering long-term outcomes.
Q4
A 6-year-old girl presents with acute onset left leg pain and refusal to bear weight. X-ray shows a lytic lesion with periosteal reaction in the femoral diaphysis demonstrating an 'onion-skin' pattern. MRI reveals a large soft tissue mass. Biopsy shows small round blue cells that are CD99 positive. Molecular studies show EWSR1-FLI1 fusion. Staging shows no metastases. Analyze the pathophysiology and treatment rationale.
Q5
A 9-year-old boy presents with painless cervical lymphadenopathy and fever. Biopsy shows Reed-Sternberg cells in a background of inflammatory cells. Staging workup reveals disease in cervical and mediastinal lymph nodes above the diaphragm without B symptoms. PET-CT shows no extranodal involvement. Analyze the stage and optimal treatment approach.
Q6
A 14-year-old boy presents with a 3-month history of right knee pain that worsens at night and is relieved by aspirin. X-ray shows a well-defined lytic lesion in the proximal tibia with surrounding sclerosis. CT scan reveals a small central nidus. Laboratory studies including alkaline phosphatase are normal. Analyze the diagnosis and management.
Q7
A 5-year-old girl presents with proptosis and periorbital ecchymosis. CT scan shows a retrobulbar mass with bone destruction. Biopsy reveals small round blue cells with Homer-Wright rosettes. Bone marrow shows tumor cells, and MIBG scan shows uptake at the primary site and multiple bone lesions. Urine VMA and HVA are elevated. N-myc is amplified. Apply the appropriate treatment strategy.
Q8
A 3-year-old boy with a 6-month history of progressive ataxia and morning headaches presents with papilledema on examination. MRI shows a 4 cm enhancing mass in the posterior fossa arising from the cerebellar vermis with obstructive hydrocephalus. The mass is well-circumscribed and has a cystic component with a mural nodule. Apply the appropriate management sequence.
Q9
A 7-year-old girl presents with fever, bone pain, and pallor. Laboratory studies show WBC 45,000/μL with 80% lymphoblasts, hemoglobin 7.5 g/dL, and platelets 25,000/μL. Flow cytometry reveals CD10+, CD19+, CD20+ cells. Cytogenetics show t(12;21) translocation. The patient has no CNS involvement. Apply the appropriate risk stratification and initial treatment approach.
Q10
A 4-year-old boy presents with a 2-week history of intermittent abdominal pain and a palpable right-sided abdominal mass. Physical examination reveals a firm, non-tender mass that crosses the midline. Blood pressure is 128/84 mmHg. Urinalysis shows microscopic hematuria. CT scan shows a large heterogeneous mass arising from the right kidney with calcifications. What is the most appropriate next step in management?
Common pediatric cancers US Medical PG Practice Questions and MCQs
Question 1: A 4-year-old boy with Down syndrome presents with fatigue and recurrent infections. CBC shows WBC 150,000/μL with 90% myeloblasts, hemoglobin 6.5 g/dL, platelets 15,000/μL. Flow cytometry confirms acute myeloid leukemia with megakaryoblastic features (AMKL). The parents are concerned about treatment intensity given their child's baseline developmental delays and increased treatment-related toxicity risk in Down syndrome. Evaluate the treatment approach considering the unique biology and competing risks.
A. Modified chemotherapy protocol with dose reductions of cytarabine but standard anthracyclines, given Down syndrome-associated AML excellent prognosis (Correct Answer)
B. Bone marrow transplantation as first-line therapy
C. Palliative care approach given poor baseline function and high treatment toxicity
D. Reduced-intensity chemotherapy due to Down syndrome and baseline developmental concerns
E. Standard AML chemotherapy protocol without modification
Explanation: ***Modified chemotherapy protocol with dose reductions of cytarabine but standard anthracyclines, given Down syndrome-associated AML excellent prognosis***
- Children with **Down syndrome-associated AML (DS-AML)**, specifically the **megakaryoblastic (AMKL)** subtype, exhibit hyper-sensitivity to **cytarabine** due to lower levels of the enzyme cytidine deaminase.
- While they have an **excellent prognosis** (cure rates >80%), they face a high risk of **treatment-related toxicity**, necessitating dose modifications to improve safety without sacrificing efficacy.
*Bone marrow transplantation as first-line therapy*
- **Hematopoietic stem cell transplant** is not indicated as first-line therapy because DS-AML responds exceptionally well to **chemotherapy** alone.
- Transplant carries a high risk of **morbidity and mortality**, which is unnecessary given the high survival rates with modified chemo regimens.
*Palliative care approach given poor baseline function and high treatment toxicity*
- Palliative care is inappropriate as the primary strategy because DS-AML is a **highly curable** malignancy in pediatric patients.
- Developmental delays and baseline status do not preclude aggressive **curative intent** therapy, as long as protocols are adjusted for toxicity.
*Reduced-intensity chemotherapy due to Down syndrome and baseline developmental concerns*
- While toxicity is a concern, broad "reduced-intensity" therapy may lead to **under-treatment** and increased risk of **relapse**.
- Specific modifications, rather than blanket reductions, are required to maintain the **high cure rate** associated with the **GATA1 mutation** characteristic of this disease.
*Standard AML chemotherapy protocol without modification*
- Using standard AML protocols in children with Down syndrome leads to **excessive toxicity**, particularly severe **mucositis** and life-threatening infections.
- The unique **pharmacogenomics** of Down syndrome patients requires dedicated protocols like the **Children's Oncology Group (COG) AAML0431** to manage treatment risks.
Question 2: A 15-year-old boy presents with right distal femur pain and a palpable mass. X-ray shows a mixed lytic-sclerotic lesion with periosteal elevation creating a Codman triangle and sunburst pattern. Biopsy confirms osteosarcoma. Staging shows pulmonary micrometastases. Alkaline phosphatase is markedly elevated. The family requests consideration of alternative therapies and limb salvage options. Synthesize the treatment plan addressing oncologic outcomes and functional preservation.
A. Limb salvage surgery without chemotherapy followed by observation
B. Radiation therapy alone as primary treatment
C. Palliative care focus given metastatic disease at presentation
D. Immediate amputation without chemotherapy due to metastatic disease
E. Neoadjuvant chemotherapy, tumor necrosis assessment, limb salvage with endoprosthesis, and adjuvant chemotherapy with potential pulmonary metastasectomy (Correct Answer)
Explanation: ***Neoadjuvant chemotherapy, tumor necrosis assessment, limb salvage with endoprosthesis, and adjuvant chemotherapy with potential pulmonary metastasectomy***
- This comprehensive approach is the standard of care; **neoadjuvant chemotherapy** treats micrometastases and allows for **tumor necrosis assessment**, a critical prognostic factor (>90% necrosis).
- **Limb salvage** is oncologically equivalent to amputation when **wide margins** are achievable, and aggressive resection of **pulmonary metastases** can still lead to long-term survival in up to 40% of patients.
*Limb salvage surgery without chemotherapy followed by observation*
- Surgery alone is insufficient because **osteosarcoma** is considered a systemic disease at diagnosis, with **pulmonary micrometastases** present in nearly all patients.
- Omitting **adjuvant chemotherapy** results in high recurrence rates and significantly lower survival outcomes.
*Radiation therapy alone as primary treatment*
- Osteosarcoma is traditionally considered a **radioresistant** tumor, making radiation therapy ineffective as a primary or sole curative modality.
- Surgical resection with **clear margins** is mandatory for local control and achieving a cure.
*Palliative care focus given metastatic disease at presentation*
- Unlike many other adult cancers, **pediatric osteosarcoma** with limited metastatic disease (especially to the lungs) is potentially curable with aggressive therapy.
- A shift to purely **palliative care** would be premature and denies the patient a significant chance at long-term survival.
*Immediate amputation without chemotherapy due to metastatic disease*
- **Immediate amputation** does not address systemic micrometastases and provides no clinical benefit over **limb salvage** if negative margins can be obtained.
- Bypassing **neoadjuvant chemotherapy** loses the opportunity to assess **chemosensitivity**, which is vital for tailoring postoperative treatment.
Question 3: A 2-year-old girl presents with a large abdominal mass, aniridia, and developmental delay. Family history reveals a sibling who died of Wilms tumor at age 3. Genetic testing shows a germline WT1 mutation. Ultrasound reveals bilateral renal masses. The parents are concerned about treatment options that preserve renal function. Evaluate the optimal management strategy considering long-term outcomes.
A. Chemotherapy followed by bilateral nephrectomy and immediate transplantation
B. Bilateral renal biopsy followed by neoadjuvant chemotherapy and bilateral nephron-sparing surgery (Correct Answer)
C. Close surveillance with delayed intervention until symptoms develop
D. Immediate bilateral nephrectomy with dialysis and future transplantation
E. Unilateral nephrectomy of the larger tumor followed by observation of contralateral kidney
Explanation: ***Bilateral renal biopsy followed by neoadjuvant chemotherapy and bilateral nephron-sparing surgery***
- The patient presents with **WAGR syndrome** (Wilms tumor, Aniridia, Genitourinary anomalies, and Range of developmental delays), which is associated with a high risk of **bilateral Wilms tumors** and subsequent chronic renal failure.
- **Neoadjuvant chemotherapy** is used to reduce tumor volume, facilitating **nephron-sparing surgery** (partial nephrectomy) to preserve as much renal parenchyma as possible and avoid the need for dialysis.
*Chemotherapy followed by bilateral nephrectomy and immediate transplantation*
- Complete **bilateral nephrectomy** results in permanent renal failure, requiring lifelong dialysis which is associated with high morbidity in very young children.
- **Kidney transplantation** is typically deferred for 1–2 years after completion of chemotherapy to ensure there is no tumor recurrence.
*Close surveillance with delayed intervention until symptoms develop*
- **Wilms tumors** are aggressive malignancies that require timely intervention to prevent local progression and **distant metastasis** (commonly to the lungs).
- Delaying treatment in a patient with a known **germline WT1 mutation** and visible masses is unethical and significantly worsens the oncologic prognosis.
*Immediate bilateral nephrectomy with dialysis and future transplantation*
- Proceeding directly to surgery without **neoadjuvant chemotherapy** misses the opportunity to shrink the tumors and increase the success rate of **nephron preservation**.
- Managing a 2-year-old on **long-term dialysis** is technically challenging and carries a significant risk of developmental delay and cardiovascular complications.
*Unilateral nephrectomy of the larger tumor followed by observation of contralateral kidney*
- Leaving a confirmed malignant tumor in the contralateral kidney without treatment allows for **metastatic spread** and continued tumor growth.
- The standard of care for bilateral disease involves treating both sides simultaneously or in a planned sequence to achieve **complete oncologic clearance**.
Question 4: A 6-year-old girl presents with acute onset left leg pain and refusal to bear weight. X-ray shows a lytic lesion with periosteal reaction in the femoral diaphysis demonstrating an 'onion-skin' pattern. MRI reveals a large soft tissue mass. Biopsy shows small round blue cells that are CD99 positive. Molecular studies show EWSR1-FLI1 fusion. Staging shows no metastases. Analyze the pathophysiology and treatment rationale.
A. Osteosarcoma requiring neoadjuvant chemotherapy and limb salvage surgery
B. Ewing sarcoma requiring neoadjuvant chemotherapy, local control with surgery or radiation, and adjuvant chemotherapy (Correct Answer)
C. Neuroblastoma requiring MIBG therapy and immunotherapy
D. Benign reactive process requiring symptomatic treatment only
E. Osteomyelitis requiring prolonged antibiotics and possible debridement
Explanation: ***Ewing sarcoma requiring neoadjuvant chemotherapy, local control with surgery or radiation, and adjuvant chemotherapy***
- The presence of **small round blue cells**, **CD99 positivity**, and the **EWSR1-FLI1 fusion** (t(11;22)) is pathognomonic for **Ewing Sarcoma**.
- Radiographic findings of an **'onion-skin' periosteal reaction** in the **diaphysis** of a long bone confirm the need for multimodal therapy including chemotherapy and local control.
*Osteosarcoma requiring neoadjuvant chemotherapy and limb salvage surgery*
- **Osteosarcoma** typically presents with a **'sunburst' pattern** or **Codman triangle** on X-ray and occurs in the **metaphysis**, not the diaphysis.
- Histology would show **malignant osteoid** production rather than concentrated small round blue cells with CD99 expression.
*Neuroblastoma requiring MIBG therapy and immunotherapy*
- While **neuroblastoma** is a small round blue cell tumor, it usually presents as an **abdominal mass** and lacks the specific **EWSR1-FLI1** translocation.
- **MIBG therapy** is specific to sympathoadrenal tumors and is not the primary treatment for primary bone malignancies like Ewing sarcoma.
*Benign reactive process requiring symptomatic treatment only*
- The presence of a **large soft tissue mass**, **lytic bone destruction**, and specific **molecular fusions** definitively rule out a benign process.
- Reactive processes do not exhibit the **malignant cellular morphology** or the high-grade clinical progression described.
*Osteomyelitis requiring prolonged antibiotics and possible debridement*
- Although osteomyelitis can cause a periosteal reaction and pain, it would typically present with **fever**, elevated **inflammatory markers**, and lack a soft tissue mass with **atypical fusions**.
- Biopsy in osteomyelitis would reveal **neutrophils** and necrotic debris (sequestrum) rather than a uniform population of **CD99-positive blue cells**.
Question 5: A 9-year-old boy presents with painless cervical lymphadenopathy and fever. Biopsy shows Reed-Sternberg cells in a background of inflammatory cells. Staging workup reveals disease in cervical and mediastinal lymph nodes above the diaphragm without B symptoms. PET-CT shows no extranodal involvement. Analyze the stage and optimal treatment approach.
A. Stage IV disease requiring bone marrow transplantation
B. Stage III disease requiring intensive chemotherapy without radiation
C. Limited stage disease requiring observation only
D. Stage I disease requiring involved-field radiation therapy alone
E. Stage II disease requiring combined modality therapy with chemotherapy and involved-field radiation (Correct Answer)
Explanation: ***Stage II disease requiring combined modality therapy with chemotherapy and involved-field radiation***
- This patient has **Stage II disease** because there are two or more lymph node regions involved (cervical and mediastinal) localized on the same side of the **diaphragm**.
- In pediatric **Hodgkin lymphoma**, the gold standard is **combined modality therapy** (risk-adapted chemotherapy plus low-dose radiation) to achieve high cure rates while limiting long-term toxicity.
*Stage IV disease requiring bone marrow transplantation*
- **Stage IV** involves diffuse or disseminated involvement of one or more **extralymphatic organs**, which is not present in this localized case.
- **Bone marrow transplantation** is generally reserved for relapsed or refractory cases, not as a primary treatment for Stage II disease.
*Stage III disease requiring intensive chemotherapy without radiation*
- **Stage III** requires involvement of lymph node regions on **both sides** of the diaphragm, whereas this patient's involvement is limited to above the diaphragm.
- **Chemotherapy alone** is sometimes studied to reduce radiation side effects, but it is not the standard for Stage III, nor does the patient meet the staging criteria.
*Limited stage disease requiring observation only*
- While this is technically a "limited stage," **Hodgkin lymphoma** is a malignant process that is never managed with **observation only**.
- Without active treatment like **ABVE-PC chemotherapy**, the disease would be progressive and fatal.
*Stage I disease requiring involved-field radiation therapy alone*
- **Stage I** involves only a single lymph node region, but this patient has both **cervical** and **mediastinal** involvement.
- **Radiation therapy alone** is historically associated with higher recurrence rates and significant long-term **late effects** in growing children.
Question 6: A 14-year-old boy presents with a 3-month history of right knee pain that worsens at night and is relieved by aspirin. X-ray shows a well-defined lytic lesion in the proximal tibia with surrounding sclerosis. CT scan reveals a small central nidus. Laboratory studies including alkaline phosphatase are normal. Analyze the diagnosis and management.
A. Osteosarcoma requiring neoadjuvant chemotherapy and limb salvage surgery
B. Ewing sarcoma requiring biopsy and multimodal therapy
C. Osteomyelitis requiring long-term antibiotics
D. Osteoid osteoma requiring radiofrequency ablation or surgical excision (Correct Answer)
E. Bone cyst requiring curettage and bone grafting
Explanation: ***Osteoid osteoma requiring radiofrequency ablation or surgical excision***
- The classic presentation of bone pain that is **worse at night** and significantly **relieved by aspirin** (NSAIDs) is highly characteristic of **osteoid osteoma**.
- Imaging reveals a pathognomonic **radiolucent nidus** (less than 2cm) surrounded by **dense reactive sclerosis**, typically found in the cortex of long bones.
*Osteosarcoma requiring neoadjuvant chemotherapy and limb salvage surgery*
- **Osteosarcoma** typically presents with a large, aggressive lesion, a **Sunburst pattern**, or **Codman triangle** on X-ray, rather than a small nidus.
- Laboratory findings often show **elevated alkaline phosphatase** and LDH due to high bone turnover, which are normal in this patient.
*Ewing sarcoma requiring biopsy and multimodal therapy*
- **Ewing sarcoma** is associated with an **"onion-skin" periosteal reaction** and a large soft tissue mass, typically in the diaphysis of long bones.
- Systemic symptoms like **fever** and **weight loss** are often present, and the pain does not specifically resolve with aspirin.
*Osteomyelitis requiring long-term antibiotics*
- **Subacute osteomyelitis** (Brodie abscess) can mimic a nidus but is usually accompanied by **elevated inflammatory markers** (ESR/CRP) and localized swelling or warmth.
- While it presents with pain, it lacks the specific **prostaglandin-mediated nocturnal pain** that responds dramatically to low-dose aspirin.
*Bone cyst requiring curettage and bone grafting*
- **Unicameral bone cysts** are fluid-filled cavities that usually present as **painless incidental findings** or as pathologic fractures, not nocturnal pain.
- X-rays show a well-circumscribed lytic lesion that expands the bone, often with the **"fallen leaf" sign** if a fracture is present, lacking surrounding sclerosis.
Question 7: A 5-year-old girl presents with proptosis and periorbital ecchymosis. CT scan shows a retrobulbar mass with bone destruction. Biopsy reveals small round blue cells with Homer-Wright rosettes. Bone marrow shows tumor cells, and MIBG scan shows uptake at the primary site and multiple bone lesions. Urine VMA and HVA are elevated. N-myc is amplified. Apply the appropriate treatment strategy.
A. Surgical resection followed by observation
B. Induction chemotherapy, surgery, consolidation with high-dose chemotherapy and stem cell rescue, radiation, and immunotherapy (Correct Answer)
C. Radiation therapy alone to all sites of disease
D. Palliative care consultation only
E. Chemotherapy alone without surgical intervention
Explanation: ***Induction chemotherapy, surgery, consolidation with high-dose chemotherapy and stem cell rescue, radiation, and immunotherapy***
- The patient presents with **high-risk neuroblastoma**, evidenced by age over 18 months, **metastasized disease** (periorbital ecchymosis/raccoon eyes), and **N-myc amplification**.
- This multi-modal approach addresses primary tumor reduction, **micrometastatic disease**, and maintenance through **immunotherapy (anti-GD2)** and **isotretinoin**.
*Surgical resection followed by observation*
- This approach is limited to **low-risk disease** (e.g., localized tumors without N-myc amplification) where surgery alone is often curative.
- In high-risk cases, observation leads to inevitable **rapid recurrence** and mortality due to undetected systemic spread.
*Radiation therapy alone to all sites of disease*
- Neuroblastoma is a systemic disease when metastatic; **localized radiation** alone cannot treat circulating tumor cells or bone marrow involvement.
- Radiation is typically reserved for **consolidation therapy** at the primary site or for **palliative** relief of painful bony metastases.
*Palliative care consultation only*
- While the prognosis for high-risk neuroblastoma is challenging, it is not currently considered a terminal-only diagnosis, with **survival rates** approaching 50% with aggressive treatment.
- Palliative care can support a patient, but omitting curative directed therapy is inappropriate given the **aggressive but potentially responsive** nature of the tumor.
*Chemotherapy alone without surgical intervention*
- While induction chemotherapy is vital, **surgical resection** of the primary mass is a critical component of local control to prevent relapse.
- Chemotherapy alone rarely achieves the complete eradication of the **primary tumor burden** necessary for long-term remission in high-risk patients.
Question 8: A 3-year-old boy with a 6-month history of progressive ataxia and morning headaches presents with papilledema on examination. MRI shows a 4 cm enhancing mass in the posterior fossa arising from the cerebellar vermis with obstructive hydrocephalus. The mass is well-circumscribed and has a cystic component with a mural nodule. Apply the appropriate management sequence.
A. External ventricular drain placement followed by tumor resection and craniospinal radiation
B. Immediate gross total resection without CSF diversion
C. Stereotactic biopsy followed by chemotherapy
D. Ventriculoperitoneal shunt followed by observation
E. External ventricular drain followed by tumor resection and chemotherapy (Correct Answer)
Explanation: ***External ventricular drain followed by tumor resection and chemotherapy***
- The patient presents with **obstructive hydrocephalus** and signs of increased intracranial pressure, necessitating immediate CSF diversion via an **external ventricular drain (EVD)**.
- For children **under 3 years of age**, treatment of a posterior fossa tumor (likely medulloblastoma) involves **maximal safe resection** followed by **chemotherapy** to avoid the devastating neurocognitive effects of radiation on a developing brain.
*External ventricular drain placement followed by tumor resection and craniospinal radiation*
- While CSF diversion and resection are standard, **craniospinal radiation** is avoided in children under 3 years due to severe **neurotoxicity** and growth delays.
- Radiation is typically reserved for older children, whereas dose-intensive **chemotherapy** is the preferred adjuvant therapy for toddlers.
*Immediate gross total resection without CSF diversion*
- Attempting resection without managing **raised intracranial pressure** and hydrocephalus increases the risk of **brain herniation** and surgical complications.
- Pre-operative **EVD placement** or steroid administration is essential to stabilize the patient before a major posterior fossa surgery.
*Stereotactic biopsy followed by chemotherapy*
- A biopsy is insufficient because **gross total resection** is the primary therapeutic goal and the most significant **prognostic factor** for survival.
- Resection also removes the source of the **aqueductal obstruction**, facilitating the long-term management of hydrocephalus.
*Ventriculoperitoneal shunt followed by observation*
- A **ventriculoperitoneal (VP) shunt** is often avoided as the first step due to the risk of **peritoneal seeding** of malignant tumor cells and shunt infection.
- Observation is inappropriate for a **posterior fossa mass** causing neurologic deficits and papilledema; aggressive surgical intervention is mandatory.
Question 9: A 7-year-old girl presents with fever, bone pain, and pallor. Laboratory studies show WBC 45,000/μL with 80% lymphoblasts, hemoglobin 7.5 g/dL, and platelets 25,000/μL. Flow cytometry reveals CD10+, CD19+, CD20+ cells. Cytogenetics show t(12;21) translocation. The patient has no CNS involvement. Apply the appropriate risk stratification and initial treatment approach.
A. Standard-risk ALL protocol with three-drug induction (Correct Answer)
B. High-risk ALL protocol with four-drug induction plus cranial radiation
C. Immediate bone marrow transplantation
D. Targeted therapy with tyrosine kinase inhibitor
E. Observation with supportive care only
Explanation: ***Standard-risk ALL protocol with three-drug induction***
- The patient is classified as **standard-risk** because she is between **1 and 9 years old**, has a **WBC count < 50,000/μL**, and carries the favorable **t(12;21) translocation**.
- Initial induction for standard-risk B-ALL typically involves a **three-drug regimen** consisting of **vincristine**, a **corticosteroid** (dexamethasone or prednisone), and **L-asparaginase**.
*High-risk ALL protocol with four-drug induction plus cranial radiation*
- **High-risk** stratification is reserved for patients aged **<1 or ≥10 years**, or those with an initial **WBC count ≥ 50,000/μL**.
- **Cranial radiation** is no longer a routine part of initial induction and is typically reserved for documented **CNS leukemia** or specific high-risk relapses.
*Immediate bone marrow transplantation*
- **Hematopoietic stem cell transplant** is not indicated as a first-line therapy for standard-risk ALL in the first complete remission.
- It is generally reserved for patients with **poor treatment response**, high-risk genetic markers like **hypoploidy**, or **relapsed disease**.
*Targeted therapy with tyrosine kinase inhibitor*
- **Tyrosine kinase inhibitors** (e.g., imatinib) are specifically used for **Philadelphia chromosome-positive (t(9;22))** ALL.
- This patient has the **t(12;21) ETV6-RUNX1** translocation, which is the most common and **prognostically favorable** rearrangement in childhood ALL, not requiring TKIs.
*Observation with supportive care only*
- Acute Lymphoblastic Leukemia is a rapidly progressive and **fatal disease** if left untreated; immediate chemotherapy is mandatory.
- **Supportive care** (transfusions, hydration) is necessary to manage symptoms and **tumor lysis syndrome** but does not address the underlying malignancy.
Question 10: A 4-year-old boy presents with a 2-week history of intermittent abdominal pain and a palpable right-sided abdominal mass. Physical examination reveals a firm, non-tender mass that crosses the midline. Blood pressure is 128/84 mmHg. Urinalysis shows microscopic hematuria. CT scan shows a large heterogeneous mass arising from the right kidney with calcifications. What is the most appropriate next step in management?
A. Immediate nephrectomy without biopsy
B. Core needle biopsy of the mass
C. Initiate chemotherapy based on imaging
D. Schedule percutaneous drainage of suspected abscess
E. Obtain urine catecholamines and metanephrines (Correct Answer)
Explanation: ***Obtain urine catecholamines and metanephrines***
- The presence of a **firm, calcified mass that crosses the midline** in a 4-year-old is highly suggestive of **neuroblastoma**, making it critical to screen for catecholamine production.
- Elevated **vanillylmandelic acid (VMA)** and **homovanillic acid (HVA)** levels are found in approximately 90% of neuroblastomas and must be assessed prior to surgical intervention to prevent **hypertensive crisis**.
*Immediate nephrectomy without biopsy*
- While surgery is a mainstay for **Wilms tumor**, performing a nephrectomy without ruling out neuroblastoma is inappropriate, as Wilms tumors rarely **cross the midline** or show **calcifications**.
- If the mass is indeed a neuroblastoma, surgical approach and adjunct therapies differ significantly from the protocols for a primary renal tumor.
*Core needle biopsy of the mass*
- Performing a biopsy on a suspected **Wilms tumor** is generally contraindicated because it can lead to **tumor seeding** and upgrade the disease to **Stage III**.
- Imaging and biochemical markers (like catecholamines) are prioritized over biopsy to differentiate between the most common pediatric abdominal malignancies.
*Initiate chemotherapy based on imaging*
- Chemotherapy is typically administered after a **tissue diagnosis** or specific biochemical confirmation is obtained, rather than based solely on a CT scan.
- While **neoadjuvant chemotherapy** is used in some protocols (especially in Europe), it follows a more definitive diagnostic workup than what is provided here.
*Schedule percutaneous drainage of suspected abscess*
- The clinical presentation of a **firm, non-tender, fixed mass** with **calcifications** and **hypertension** is inconsistent with an abscess, which would typically involve fever and leukocytosis.
- Percutaneous drainage of a malignant mass like a **neuroblastoma** or **Wilms tumor** would be harmful, risking **hemorrhage** and the spread of malignant cells.
