Common pediatric cancers

Common pediatric cancers US Medical PG Question 1: A 12-month-old girl is brought to her pediatrician for a checkup and vaccines. The patient’s mother wants to send her to daycare but is worried about exposure to unvaccinated children and other potential sources of infection. The toddler was born at 39 weeks gestation via spontaneous vaginal delivery. She is up to date on all vaccines. She does not walk yet but stands in place and can say a few words. The toddler drinks formula and eats a mixture of soft vegetables and pureed meals. She has no current medications. On physical exam, the vital signs include: temperature 37.0°C (98.6°F), blood pressure 95/50 mm Hg, pulse 130/min, and respiratory rate 28/min. The patient is alert and responsive. The remainder of the exam is unremarkable. Which of the following is most appropriate for this patient at this visit?

• A. Meningococcal vaccine
• B. Gross motor workup and evaluation
• C. Rotavirus vaccine
• D. Referral for speech pathology
• E. MMR vaccine (Correct Answer)

Common pediatric cancers Explanation: ***MMR vaccine*** - The **measles, mumps, and rubella (MMR) vaccine** is recommended for administration at **12-15 months of age**. - This timing offers protection against these common childhood diseases, which is especially important for children attending **daycare**. *Meningococcal vaccine* - The routine **meningococcal vaccine (MenACWY)** is typically recommended for adolescents at **11-12 years of age**, with a booster at 16 years. - While there are specific circumstances for earlier vaccination (e.g., high-risk conditions), it is **not routine** for a 12-month-old. *Gross motor workup and evaluation* - The patient's motor development, standing in place but not yet walking, is **within the normal range** for a 12-month-old. - A definitive **gross motor workup** would generally be considered if there were more significant delays or regressions. *Rotavirus vaccine* - The **rotavirus vaccine** series is typically given at **2, 4, and 6 months of age**, with the final dose administered no later than **8 months of age**. - A 12-month-old is **outside the recommended age range** for initiating or completing this vaccine series. *Referral for speech pathology* - Saying "a few words" at 12 months is **within the normal developmental milestone** for expressive language at this age. - A referral for **speech pathology** would generally be indicated for more significant language delays.

Common pediatric cancers US Medical PG Question 2: A 3-year-old male child is found to have a disease involving DNA repair. Specifically, he is found to have a defect in the endonucleases involved in the nucleotide excision repair of pyrimidine dimers. Which of the following is a unique late-stage complication of this child's disease?

• A. Telangiectasia
• B. Colorectal cancer
• C. Malignant melanoma (Correct Answer)
• D. Lymphomas
• E. Endometrial cancer

Common pediatric cancers Explanation: **Malignant melanoma** - The described condition is **xeroderma pigmentosum**, an autosomal recessive disorder characterized by a defect in **nucleotide excision repair (NER)**, specifically the inability to remove **pyrimidine dimers** caused by **UV radiation**. - This severely impaired DNA repair leads to an extreme predisposition to **UV-induced skin cancers**, including basal cell carcinomas, squamous cell carcinomas, and, most aggressively, **malignant melanoma**, which is a unique and life-threatening late-stage complication. *Telangiectasia* - **Telangiectasias** are dilated small blood vessels that appear on the skin or mucous membranes and can be associated with various conditions. - While skin abnormalities are prevalent in xeroderma pigmentosum due to sun damage, **melanoma** is a more specific and severe late-stage complication directly resulting from the DNA repair defect. *Colorectal cancer* - **Colorectal cancer** is typically associated with other DNA repair defects, such as those in the **mismatch repair system**, as seen in conditions like **Lynch syndrome**. - It is not a primary or most significant late-stage complication of xeroderma pigmentosum, which is primarily characterized by skin cancers. *Lymphomas* - **Lymphomas** are cancers of the lymphatic system, often linked to immune deficiencies or specific genetic translocations. - While individuals with genetic syndromes can have increased cancer risks, **lymphoma** is not the hallmark late-stage complication of xeroderma pigmentosum; skin cancers are the predominant concern. *Endometrial cancer* - **Endometrial cancer** is a gynecological cancer often associated with hormonal factors or genetic predispositions like Lynch syndrome, which involves mismatch repair defects. - This type of cancer is not a characteristic or unique late-stage complication of xeroderma pigmentosum, whose pathology is centered on **UV-induced DNA damage** and subsequent skin malignancies.

Common pediatric cancers US Medical PG Question 3: A 4-year-old girl is being followed by the pediatric oncology team after her pediatrician found a palpable abdominal mass towards the right flank 2 weeks ago. Abdominal ultrasonography detected a solid mass in the right kidney without infiltration of the renal vein and inferior vena cava. The contrast-enhanced computed tomography (CT) confirmed the presence of a solitary mass in the right kidney surrounded by a pseudocapsule consisting of a rim of normal tissue, displacing it medially, and distorting the collecting system. No nodal involvement was detected. In which of the following chromosomes would you expect a genetic abnormality?

• A. Chromosome 13
• B. Chromosome 1
• C. Chromosome 3
• D. Chromosome 22
• E. Chromosome 11 (Correct Answer)

Common pediatric cancers Explanation: ***Chromosome 11*** - This clinical presentation, particularly the **solitary renal mass** in a 4-year-old and the imaging findings of a **pseudocapsule** and displacement of the collecting system, is highly suggestive of **Wilms tumor (nephroblastoma)**. - **Wilms tumor** is associated with genetic abnormalities, most notably mutations in the **WT1 gene** located on **chromosome 11p13**, and the **WT2 locus** on **chromosome 11p15.5**. *Chromosome 13* - Abnormalities on **chromosome 13** are primarily associated with **retinoblastoma**, linked to mutations in the **RB1 gene**. - While retinoblastoma is a childhood cancer, its presentation involves ocular tumors, not renal masses. *Chromosome 1* - Genetic abnormalities on **chromosome 1** are implicated in various cancers and conditions, but they are not the primary or most characteristic genetic defect associated with **Wilms tumor**. - Specific translocations or deletions on chromosome 1 can be seen in certain leukemias and lymphomas, which do not fit the clinical picture. *Chromosome 3* - **Chromosome 3** abnormalities are well-known in various malignancies, most notably **renal cell carcinoma (RCC)**, particularly the **von Hippel-Lindau (VHL) gene** at 3p25-26. - RCC is typically a cancer of adulthood, and VHL disease presents with multiple organ system involvement, differing from a solitary renal mass in a young child. *Chromosome 22* - Abnormalities on **chromosome 22** are frequently associated with conditions like **neurofibromatosis type 2** (NF2 gene) and **DiGeorge syndrome** (22q11 deletion). - The presentation of a renal mass in a child is not characteristic of genetic defects on chromosome 22.

Common pediatric cancers US Medical PG Question 4: A 5-year-old boy presents to his pediatrician with weakness. His father observed that his son seemed less energetic at daycare and kindergarten classes. He was becoming easily fatigued from mild play. His temperature is 98°F (37°C), blood pressure is 90/60 mmHg, pulse is 100/min, and respirations are 20/min. Physical exam reveals pale conjunctiva, poor skin turgor and capillary refill, and cervical and axillary lymphadenopathy with assorted bruises throughout his body. A complete blood count reveals the following: Leukocyte count: 3,000/mm^3 Segmented neutrophils: 30% Bands: 5% Eosinophils: 5% Basophils: 10% Lymphocytes: 40% Monocytes: 10% Hemoglobin: 7.1 g/dL Hematocrit: 22% Platelet count: 50,000/mm^3 The most specific diagnostic assessment would most likely show which of the following?

• A. Bone marrow biopsy with ≥ 20% lymphoblasts (Correct Answer)
• B. Fluorescence in situ hybridization analysis with 9:22 translocation
• C. Peripheral blood smear with > 50% lymphoblasts
• D. Flow cytometry with positive terminal deoxynucleotidyl transferase staining
• E. Fluorescence in situ hybridization analysis with 12:21 translocation

Common pediatric cancers Explanation: ***Bone marrow biopsy with ≥ 20% lymphoblasts*** - The patient's symptoms (weakness, fatigue, pallor, bruising, lymphadenopathy) and blood counts (anemia, thrombocytopenia, leukopenia with relative lymphocytosis) are highly suggestive of **Acute Lymphoblastic Leukemia (ALL)**. - The most specific diagnostic assessment for ALL involves a **bone marrow biopsy** showing **≥20% lymphoblasts** per WHO 2016 classification, confirming the abnormal proliferation of immature lymphoid cells. - This is the **gold standard** for diagnosing ALL and distinguishes it from other hematologic disorders. *Fluorescence in situ hybridization analysis with 9:22 translocation* - The **Philadelphia chromosome (t[9;22])** is characteristic of **Chronic Myeloid Leukemia (CML)**, which is rare in children and presents differently. - While t(9;22) can occur in 3-5% of childhood ALL and indicates poor prognosis, it is a **prognostic marker**, not the primary diagnostic criterion for ALL itself. *Peripheral blood smear with > 50% lymphoblasts* - While lymphoblasts can be seen in the peripheral blood in ALL, a specific percentage threshold in peripheral blood is **not a diagnostic criterion** for ALL. - The peripheral blood smear can be suggestive, but the **bone marrow blast percentage is the gold standard** for definitive diagnosis. *Flow cytometry with positive terminal deoxynucleotidyl transferase staining* - **Terminal deoxynucleotidyl transferase (TdT)** is a nuclear enzyme expressed in pre-B and pre-T lymphoblasts and is an important marker for ALL. - Flow cytometry with positive TdT staining helps **characterize and classify the blasts** but does not quantify the blast percentage required for diagnosis, which is provided by the bone marrow biopsy. *Fluorescence in situ hybridization analysis with 12:21 translocation* - The **t(12;21) [ETV6-RUNX1] translocation** is the most common cytogenetic abnormality in childhood B-cell ALL (20-25% of cases) and is associated with favorable prognosis. - While its presence is relevant for risk stratification and treatment planning, the primary diagnostic criterion for ALL is the **percentage of lymphoblasts in the bone marrow**.

Common pediatric cancers US Medical PG Question 5: A research group wants to assess the safety and toxicity profile of a new drug. A clinical trial is conducted with 20 volunteers to estimate the maximum tolerated dose and monitor the apparent toxicity of the drug. The study design is best described as which of the following phases of a clinical trial?

• A. Phase 0
• B. Phase III
• C. Phase V
• D. Phase II
• E. Phase I (Correct Answer)

Common pediatric cancers Explanation: ***Phase I*** - **Phase I clinical trials** involve a small group of healthy volunteers (typically 20-100) to primarily assess **drug safety**, determine a safe dosage range, and identify side effects. - The main goal is to establish the **maximum tolerated dose (MTD)** and evaluate the drug's pharmacokinetic and pharmacodynamic profiles. *Phase 0* - **Phase 0 trials** are exploratory studies conducted in a very small number of subjects (10-15) to gather preliminary data on a drug's **pharmacodynamics and pharmacokinetics** in humans. - They involve microdoses, not intended to have therapeutic effects, and thus cannot determine toxicity or MTD. *Phase III* - **Phase III trials** are large-scale studies involving hundreds to thousands of patients to confirm the drug's **efficacy**, monitor side effects, compare it to standard treatments, and collect information that will allow the drug to be used safely. - These trials are conducted after safety and initial efficacy have been established in earlier phases. *Phase V* - "Phase V" is not a standard, recognized phase in the traditional clinical trial classification (Phase 0, I, II, III, IV). - This term might be used in some non-standard research contexts or for post-marketing studies that go beyond Phase IV surveillance, but it is not a formal phase for initial drug development. *Phase II* - **Phase II trials** involve several hundred patients with the condition the drug is intended to treat, focusing on **drug efficacy** and further evaluating safety. - While safety is still monitored, the primary objective shifts to determining if the drug works for its intended purpose and at what dose.

Common pediatric cancers US Medical PG Question 6: An 11-year-old girl is brought to the emergency department because of high-grade fever, headache, and nausea for 3 days. She avoids looking at any light source because this aggravates her headache. She has acute lymphoblastic leukemia and her last chemotherapy cycle was 2 weeks ago. She appears lethargic. Her temperature is 40.1°C (104.2°F), pulse is 131/min and blood pressure is 100/60 mm Hg. Examination shows a stiff neck. The pupils are equal and reactive to light. Neck flexion results in flexion of the knee and hip. Muscle strength is decreased in the right upper extremity. Deep tendon reflexes are 2+ bilaterally. Sensation is intact. Extraocular movements are normal. Two sets of blood cultures are obtained. Which of the following is the most appropriate next step in management?

• A. Acyclovir therapy
• B. Antibiotic therapy (Correct Answer)
• C. MRI of the brain
• D. CT scan of the head
• E. Lumbar puncture

Common pediatric cancers Explanation: ***Antibiotic therapy*** - This patient presents with **fever, headache, stiff neck, photophobia, and positive Brudzinski's sign (neck flexion results in flexion of the knee and hip)**, which are classic signs of **meningitis**. Given her history of **acute lymphoblastic leukemia (ALL)** and recent chemotherapy, she is **immunocompromised** and at high risk for **bacterial meningitis**, a life-threatening infection requiring immediate antibiotic treatment. - Due to the severity of symptoms and the high risk in an immunocompromised patient, immediate initiation of empiric, broad-spectrum antibiotics is crucial after obtaining blood cultures, even before definitive diagnosis from cerebrospinal fluid (CSF) analysis. *Acyclovir therapy* - **Acyclovir** is an antiviral medication used to treat herpes simplex virus (HSV) or varicella-zoster virus (VZV) encephalitis or meningitis. - While viral meningitis is a possibility, bacterial meningitis is a more urgent and severe concern in an immunocompromised patient with these neurological signs, making immediate antibiotics a higher priority. *MRI of the brain* - An **MRI of the brain** provides detailed imaging of brain structures and can detect abscesses, tumors, or inflammation. - However, in acute meningitis, especially with signs of increased intracranial pressure (which should be ruled out before LP), antibiotics are the most immediate and critical intervention, and an MRI would delay this life-saving treatment. *CT scan of the head* - A **CT scan of the head** is primarily used to rule out **mass lesions, hydrocephalus, or significant cerebral edema** before performing a **lumbar puncture (LP)** in patients with suspected meningitis who have focal neurological deficits or signs of increased intracranial pressure. - While it may be considered before LP due to the focal neurological deficit (decreased muscle strength in the right upper extremity), administering antibiotics takes precedence due to the high suspicion of bacterial meningitis in an immunocompromised patient. *Lumbar puncture* - A **lumbar puncture** is essential for diagnosing meningitis by analyzing the **cerebrospinal fluid (CSF)** for cell count, glucose, protein, and culture. - However, performing an LP can be delayed if there are signs of increased intracranial pressure (which warrants a preceding CT scan) or if the patient's condition is unstable; importantly, **empiric antibiotics should be started immediately** in a suspected bacterial meningitis case, especially in an immunocompromised patient, and not delayed for imaging or LP.

Common pediatric cancers US Medical PG Question 7: An 18-month-old boy is brought to the doctor’s office for evaluation of abdominal pain. The boy looks emaciated and he is now significantly below his growth chart predicted weight. The family history is non-contributory. The vital signs are unremarkable. On physical examination, a non-tender mass is felt in the upper part of the abdomen. A magnetic resonance image (MRI) scan of his abdomen demonstrates a mass in his right adrenal gland. Biopsy of the mass demonstrates an abundance of small round blue cells. With this biopsy result, which 1 of the following findings would confirm the diagnosis?

• A. Elevation of vanillylmandelic acid in the urine (Correct Answer)
• B. MRI showing the intrarenal origin of the mass
• C. Increased lactic dehydrogenase
• D. Increased alpha-fetoprotein
• E. Radiograph of the bone showing the presence of lytic bone lesion with periosteal reaction

Common pediatric cancers Explanation: ***Elevation of vanillylmandelic acid in the urine*** - The clinical presentation (abdominal mass, emaciation, age) and biopsy finding of **small round blue cells** in the adrenal gland are highly suggestive of **neuroblastoma**. - **Neuroblastomas** arise from neural crest cells and characteristically produce **catecholamines**, leading to elevated urinary levels of their metabolites like **vanillylmandelic acid (VMA)** and **homovanillic acid (HVA)**. *MRI showing the intrarenal origin of the mass* - An **intrarenal origin** of the mass would suggest a **Wilms tumor** (nephroblastoma), which is another common pediatric abdominal malignancy. - However, the mass is described as being in the **adrenal gland**, and the biopsy shows small round blue cells, which are characteristic of neuroblastoma rather than Wilms tumor. *Increased lactic dehydrogenase* - Elevated **lactic dehydrogenase (LDH)** is a non-specific tumor marker often associated with a high tumor burden and rapid cell turnover in various malignancies, including neuroblastoma. - While it can be elevated in neuroblastoma, it is not a specific diagnostic marker and would not confirm the diagnosis over other pediatric cancers. *Increased alpha-fetoprotein* - Elevated **alpha-fetoprotein (AFP)** is primarily associated with **hepatoblastoma** and **germ cell tumors**. - It is not typically elevated in neuroblastoma and would therefore not confirm this diagnosis. *Radiograph of the bone showing the presence of lytic bone lesion with periosteal reaction* - While **neuroblastoma** can metastasize to bones, causing **lytic bone lesions** and a periosteal reaction, these findings indicate metastatic disease rather than confirming the primary diagnosis. - A bone radiograph showing such lesions points to advanced disease but doesn't specifically confirm neuroblastoma as the primary tumor type.

Common pediatric cancers US Medical PG Question 8: A 2-year-old boy is brought to the physician because of progressive difficulty breathing and a productive cough for the past 2 days. During the past 6 months, he has had recurrent episodes of pneumonia treated with antibiotics. He has not gained weight in this time period. His temperature is 38.5°C (101.3°F), pulse is 130/min, respirations are 18/min, and blood pressure is 100/60 mm Hg. Auscultation of the lungs shows decreased breath sounds over the right lung fields. Ocular examination shows periorbital subcutaneous bleeding and bulging of both eyes. His leukocyte count is 16,000/mm3. An x-ray of the chest shows a right-sided opacity and a collapsed right lung. An MRI of the chest shows a heterogeneous mass in the posterior mediastinum that compresses the heart and the great vessels to the left side. Further evaluation is most likely to show which of the following?

• A. Unregulated B-cell proliferation in the mediastinum
• B. Acid-fast bacteria on sputum microscopy
• C. Increased lymphoblast count in the bone marrow
• D. Overexpression of the N-myc oncogene (Correct Answer)
• E. Autoantibodies against nicotinic acetylcholine receptors

Common pediatric cancers Explanation: ***Overexpression of the N-myc oncogene*** - The combination of a posterior mediastinal mass, periorbital bruising (**raccoon eyes**), and proptosis in a 2-year-old child with recurrent infections and failure to thrive is highly suggestive of **neuroblastoma**. - **N-myc oncogene amplification** is a common genetic abnormality found in high-risk neuroblastoma and correlates with aggressive disease and poor prognosis. *Unregulated B-cell proliferation in the mediastinum* - This would suggest a **lymphoma**, which typically presents with anterior or superior mediastinal masses and often involves lymphadenopathy. - The specific ocular findings of periorbital ecchymoses and proptosis are not characteristic of lymphoma but are classic for metastatic neuroblastoma. *Acid-fast bacteria on sputum microscopy* - This finding is indicative of **tuberculosis**, which can cause mediastinal lymphadenopathy and pulmonary symptoms. - However, tuberculosis would not typically cause a large heterogeneous posterior mediastinal mass with associated periorbital ecchymoses and proptosis. *Increased lymphoblast count in the bone marrow* - This points to **acute lymphoblastic leukemia (ALL)**. While ALL can cause mediastinal masses (T-cell ALL often presents with an anterior mediastinal mass) and systemic symptoms, the **periorbital bruising and proptosis** are specific features that distinguish neuroblastoma. - Also, a significantly increased lymphoblast count in the bone marrow is the defining diagnostic criterion for leukemia, which is not directly suggested by the initial presentation beyond general systemic illness. *Autoantibodies against nicotinic acetylcholine receptors* - This finding is characteristic of **myasthenia gravis**, an autoimmune neuromuscular disorder. - Myasthenia gravis presents with **muscle weakness and fatigue**, not a posterior mediastinal mass, recurrent pneumonia, failure to thrive, or ocular bulging/bruising as described.

Common pediatric cancers US Medical PG Question 9: A 5-year-old boy is brought to the pediatric clinic for evaluation of fever, pain, swelling in the left leg, and limping. Review of systems and history is otherwise unremarkable. The vital signs include: pulse 110/min, temperature 38.1°C (100.6°F), and blood pressure 100/70 mm Hg. On examination, there is a tender swelling over the lower part of his left leg. Which 1 of the following X-ray findings is most suggestive of Ewing’s sarcoma?

• A. Mixed lytic and blastic appearance in the X-ray
• B. X-ray showing broad-based projections from the surface of the bone
• C. X-ray showing lytic bone lesion with periosteal reaction (Correct Answer)
• D. X-ray showing a sharply marginated radiolucent area within the apophysis
• E. X-ray showing deep muscle plane displacement from the metaphysis

Common pediatric cancers Explanation: ***X-ray showing lytic bone lesion with periosteal reaction*** - **Ewing's sarcoma** typically presents as a **lytic bone lesion** with an **aggressive periosteal reaction**, often described as an **"onion-skin" appearance** due to layers of new bone formation. - The combination of fever, localized pain, swelling, and limping in a child, along with a lytic lesion and periosteal reaction on X-ray, is highly suggestive of this diagnosis. *Mixed lytic and blastic appearance in the X-ray* - A mixed lytic and blastic appearance is more characteristic of metastatic disease or certain other bone tumors like osteosarcoma in later stages, but less specific for primary Ewing's sarcoma. - While some blastic components can occur, the primary hallmark of Ewing's is its lytic and destructive nature with typical periosteal reactions. *X-ray showing broad-based projections from the surface of the bone* - Broad-based projections from the bone surface are characteristic of **osteochondromas**, which are benign bone tumors. - These are typically painless unless they impinge on nerves or blood vessels, and do not usually present with systemic symptoms like fever. *X-ray showing a sharply marginated radiolucent area within the apophysis* - A sharply marginated radiolucent area within the apophysis could suggest a benign lesion like a **fibrous cortical defect** or a **non-ossifying fibroma**, particularly if it is well-defined and non-aggressive. - It does not indicate the aggressive, destructive nature seen with Ewing's sarcoma. *X-ray showing deep muscle plane displacement from the metaphysis* - Deep muscle plane displacement can indicate a significant soft tissue mass, but it is a **non-specific finding** and does not point directly to the bony destruction or characteristic periosteal reaction of Ewing's sarcoma. - This finding could be associated with various soft tissue tumors, hematomas, or infections.

Common pediatric cancers US Medical PG Question 10: A 7-year-old girl is brought to the physician by her mother because of a 2-week history of generalized fatigue, intermittent fever, and progressively worsening shortness of breath. Physical examination shows pallor, jugular venous distention, and nontender cervical and axillary lymphadenopathy. Inspiratory stridor is heard on auscultation of the chest. The liver is palpated 3 cm below the right costal margin. Her hemoglobin concentration is 9.5 g/dL, leukocyte count is 66,000/mm³, and platelet count is 102,000/mm³. An x-ray of the chest shows a mediastinal mass. A bone marrow aspirate predominantly shows leukocytes and presence of 35% lymphoblasts. Which of the following additional findings is most likely in this patient?

• A. t(8;14) translocation
• B. Positive myeloperoxidase staining
• C. Positive CD3/CD7 staining (Correct Answer)
• D. t(9;22) translocation
• E. Reed-Sternberg cells

Common pediatric cancers Explanation: ***Positive CD3/CD7 staining*** - The presence of a **mediastinal mass** with **T-cell lymphoblastic leukemia/lymphoma (T-ALL)** is highly associated with a **T-cell immunophenotype**. **CD3** and **CD7** are **T-cell surface markers**. - The constellation of findings, including **lymphadenopathy**, **hepatomegaly**, **bone marrow involvement** with 35% lymphoblasts, and a **mediastinal mass** causing **stridor**, is classic for T-ALL, which is typically of T-cell origin. *t(8;14) translocation* - This translocation is characteristic of **Burkitt lymphoma**, which typically presents as an **extranodal mass** (e.g., jaw, abdomen) rather than a primary mediastinal mass causing stridor. - While Burkitt lymphoma is also a B-cell non-Hodgkin lymphoma and can have bone marrow involvement, the clinical picture here is not typical for Burkitt lymphoma. *Positive myeloperoxidase staining* - **Myeloperoxidase** is an enzyme found in the granules of **myeloid cells**, and its staining is characteristic of **acute myeloid leukemia (AML)**. - While the patient has leukocytosis and anemia, the predominance of **lymphoblasts** in the bone marrow aspirate points away from AML. *t(9;22) translocation* - The **Philadelphia chromosome**, associated with **t(9;22) translocation**, is highly characteristic of **chronic myeloid leukemia (CML)** and can be seen in a subset of **B-cell acute lymphoblastic leukemia (B-ALL)**. - However, the clinical presentation with a large mediastinal mass causing stridor is more typical of T-ALL, which is not strongly associated with t(9;22). *Reed-Sternberg cells* - **Reed-Sternberg cells** are the hallmark of **Hodgkin lymphoma**. - While Hodgkin lymphoma can present with **mediastinal mass** and **lymphadenopathy**, it typically affects older children/adolescents or young adults, and the presence of **35% lymphoblasts** in the bone marrow indicates leukemia, not Hodgkin lymphoma.

Common pediatric cancers Flashcard 1 of 6

Question: What is the most common germ cell tumor in children (esp. male infants)? _____

Answer: Endodermal sinus (yolk sac) tumor

Common pediatric cancers Flashcard 2 of 6

Question: _____ syndrome often results in missed school or overuse of medical services

Answer: Vulnerable child

Common pediatric cancers Flashcard 3 of 6

Question: What demographic (age group) is most commonly associated with acute lymphoblastic leukemia (ALL)? _____

Answer: Children

Common pediatric cancers Flashcard 4 of 6

Question: What is the most common tumor of the adrenal medulla in children? _____

Answer: Neuroblastoma

Common pediatric cancers Flashcard 5 of 6

Question: Fanconi anemia is associated with an increased risk of developing _____

Answer: cancer (e.g. tumors, leukemia)

Common pediatric cancers Flashcard 6 of 6

Question: 14 yo pt w/ clean, minor wound and unknown immunization hx is managed with _____

Answer: active immunization with Tdap

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