A 15-year-old adolescent is brought to the physician by her parents. She is concerned that she has not started menstruating yet. She is also self-conscious because her chest has not yet developed and all of her friends are taller and much more developed. Past medical history is noncontributory. Her mother started menstruating around the age of 13 and her older sister at the age of 12. The patient is more concerned about her poor performance in sports. She says that she can not participate in sports like before and gets tired very early. Today, her heart rate is 90/min, respiratory rate is 17/min, blood pressure is 110/65 mm Hg, and temperature of 37.0°C (98.6°F). On physical exam, her heart has a regular rate and rhythm and lungs are clear to auscultation bilaterally. On physical exam, her brachial pulses appear bounding (4+) and her femoral pulses are diminished (2+). Her legs also appear mildly atrophic with poor muscle development bilaterally. Her neck appears short with excessive skin in the lateral neck area. This patient’s symptoms are most likely associated with which of the following conditions?
Q122
A newborn girl is rushed to the neonatal ICU after an emergency cesarean section due to unstable vital signs after delivery. The pregnancy was complicated due to oligohydramnios and pulmonary hypoplasia. Gestation was at 38 weeks. APGAR scores were 6 and 8 at 1 and 5 minutes respectively. The newborn’s temperature is 37.0°C (98.6°F), the blood pressure is 60/40 mm Hg, the respiratory rate is 45/min, and the pulse is 140/min. Physical examination reveals irregularly contoured bilateral abdominal masses. Abdominal ultrasound reveals markedly enlarged echogenic kidneys (5 cm in the vertical dimension) with multiple cysts in the cortex and medulla. This patient is at highest risk of which of the following complications?
Q123
A 6-month-old boy is brought to the physician because of a right-sided scrotal swelling for the past 2 months. The swelling is intermittent and appears usually after the patient has been taken outdoors in a baby carrier, and disappears the next morning. The patient was born at term without complications and has been healthy. Examination shows a 3-cm, soft, nontender, and fluctuant right scrotal mass that is reducible and does not extend into the inguinal area. A light held behind the scrotum shines through. There are no bowel sounds in the mass. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in the management of this patient?
Q124
A 5-day-old boy is brought to see his pediatrician after his newborn blood screening showed elevated levels of immunoreactive trypsinogen, a marker for cystic fibrosis. The boy was born at 39 weeks gestation after regular prenatal care. He has 2 siblings that tested negative on screening. On physical exam, his vitals are normal and he appears healthy. Which of the following tests should be performed next to evaluate the newborn for cystic fibrosis?
Q125
A 4-month-old boy is brought by his mother to the pediatrician for a routine check-up. He was born at 39 weeks' gestation with a birth weight of 2.1 kg. Apgar scores were 6 and 8 at 1 and 5 minutes, respectively. The child has had feeding difficulties requiring supplemental feeding and frequent awakening at night. He has delayed developmental milestones and does not yet smile spontaneously. He is behind on his vaccination schedule due to frequent illnesses. His temperature is 98.6°F (37°C), blood pressure is 95/60 mmHg, pulse is 140/min, and respirations are 35/min. On physical examination, he has microcephaly, a prominent forehead, hypertelorism, a broad nasal bridge, and micrognathia. He also has hypotonia and is unable to hold his head steady when unsupported. This patient's condition is associated with a mutation in which of the following chromosomes?
Q126
A 1-month-old infant is brought to the physician for a well-child examination. His mother reports that she had previously breastfed her son every 2 hours for 15 minutes but is now feeding him every 4 hours for 40 minutes. She says that the infant sweats a lot and is uncomfortable during feeds. He has 6 wet diapers and 2 stools daily. He was born at 36 weeks' gestation. He currently weighs 3500 g (7.7 lb) and is 52 cm (20.4 in) in length. He is awake and alert. His temperature is 37.1°C (98.8°F), pulse is 170/min, respirations are 55/min, and blood pressure is 80/60 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 99%. Cardiopulmonary examination shows a 4/6 continuous murmur along the upper left sternal border. After confirming the diagnosis via echocardiography, which of the following is the most appropriate next step in the management of this patient?
Q127
A 14-month-old boy has iron-deficiency anemia refractory to iron therapy. His stool is repeatedly positive for occult blood. The parents bring the child to the emergency room after they notice some blood in his stool. Which of the following is the diagnostic gold standard for this patient's most likely condition?
Q128
A 31-year-old woman delivers a healthy boy at 38 weeks gestation. The delivery is vaginal and uncomplicated. The pregnancy was unremarkable. On examination of the newborn, it is noted that his head is tilted to the left and his chin is rotated to the right. Palpation reveals no masses or infiltration in the neck. The baby also shows signs of left hip dysplasia. Nevertheless, the baby is active and exhibits no signs of other pathology. What is the most probable cause of this patient's condition?
Q129
Over the course of a year, 5 children with identical congenital heart defects were referred to a pediatric cardiac surgeon for evaluation. All 5 children had stable vital signs and were on appropriate medication. Upon review of medical records, all of them had a loud holosystolic murmur over the third intercostal space at the left sternal border. The surgeon ordered echocardiograms for all 5 children and recommended surgical closure of the defect in one of them. Which of the following patients required surgical repair of their defect?
Q130
A 7-year-old girl presents with a lump in her neck which she noticed a few days ago. The patient's mother states that her daughter's left eyelid seems to be drooping, making her left eye look small. There is no significant past medical history. On neurological examination, the patient has normal bilateral pupillary reflexes but a miotic left pupil. A lateral radiograph of the chest reveals a mass in the posterior mediastinum with no evidence of bone erosion. An MRI is performed and the results are shown in the image. An imaging-guided biopsy of the mass reveals spindle-shaped cells arranged chaotically, with moderate cytoplasm and small nuclei. Scattered mature ganglion cells with abundant cytoplasm and round to oval nuclei are also present. The biopsy tissue is analyzed with immunohistochemistry and found to be positive for S-100, synaptophysin, and chromogranin. Which of the following factors is associated with poor prognosis for this patient's most likely diagnosis?
Congenital defects US Medical PG Practice Questions and MCQs
Question 121: A 15-year-old adolescent is brought to the physician by her parents. She is concerned that she has not started menstruating yet. She is also self-conscious because her chest has not yet developed and all of her friends are taller and much more developed. Past medical history is noncontributory. Her mother started menstruating around the age of 13 and her older sister at the age of 12. The patient is more concerned about her poor performance in sports. She says that she can not participate in sports like before and gets tired very early. Today, her heart rate is 90/min, respiratory rate is 17/min, blood pressure is 110/65 mm Hg, and temperature of 37.0°C (98.6°F). On physical exam, her heart has a regular rate and rhythm and lungs are clear to auscultation bilaterally. On physical exam, her brachial pulses appear bounding (4+) and her femoral pulses are diminished (2+). Her legs also appear mildly atrophic with poor muscle development bilaterally. Her neck appears short with excessive skin in the lateral neck area. This patient’s symptoms are most likely associated with which of the following conditions?
A. Friedreich ataxia
B. Marfan syndrome
C. Turner syndrome (Correct Answer)
D. Kartagener's syndrome
E. Down syndrome
Explanation: ***Turner syndrome***
- The patient's presentation with **primary amenorrhea**, **lack of breast development**, **short stature**, **bounding brachial pulses** with **diminished femoral pulses** (suggesting coarctation of the aorta), and a **short neck with excessive skin** (webbed neck) are classic features of **Turner syndrome (45,XO)**.
- **Poor athletic performance** and **fatigue** can be attributed to the cardiovascular defect (coarctation), which reduces blood flow to the lower body and can lead to claudication or muscle weakness.
*Friedreich ataxia*
- This is a **neurodegenerative disorder** characterized by **progressive ataxia**, dysarthria, and scoliosis, often presenting in childhood or adolescence.
- While it can cause **cardiomyopathy** and fatigue, it does not typically present with the specific physical stigmata like webbed neck, short stature, or primary amenorrhea.
*Marfan syndrome*
- Characterized by tall stature, **arachnodactyly (long, slender fingers)**, **pectus excavatum**, **joint laxity**, and cardiovascular abnormalities like **aortic root dilation** and dissection.
- It does not cause short stature, webbed neck, primary amenorrhea, or coarctation of the aorta.
*Kartagener's syndrome*
- A subset of **primary ciliary dyskinesia**, characterized by the triad of **situs inversus**, **chronic sinusitis**, and **bronchiectasis**.
- This condition affects ciliary function and is not associated with the **gonadal dysgenesis**, **short stature**, or specific cardiovascular and physical anomalies seen in the patient.
*Down syndrome*
- Caused by **trisomy 21**, typically presenting with **intellectual disability**, **distinctive facial features** (e.g., epicanthic folds, upslanting palpebral fissures), single palmar crease, and often **congenital heart defects** (e.g., AV septal defects).
- While it can be associated with short stature and heart defects, it does not cause primary amenorrhea due to gonadal dysgenesis, webbed neck as a primary feature, or coarctation in the pattern described.
Question 122: A newborn girl is rushed to the neonatal ICU after an emergency cesarean section due to unstable vital signs after delivery. The pregnancy was complicated due to oligohydramnios and pulmonary hypoplasia. Gestation was at 38 weeks. APGAR scores were 6 and 8 at 1 and 5 minutes respectively. The newborn’s temperature is 37.0°C (98.6°F), the blood pressure is 60/40 mm Hg, the respiratory rate is 45/min, and the pulse is 140/min. Physical examination reveals irregularly contoured bilateral abdominal masses. Abdominal ultrasound reveals markedly enlarged echogenic kidneys (5 cm in the vertical dimension) with multiple cysts in the cortex and medulla. This patient is at highest risk of which of the following complications?
A. Portal hypertension (Correct Answer)
B. Subarachnoid hemorrhage
C. Acute renal failure
D. Recurrent UTI
E. Emphysema
Explanation: ***Portal hypertension***
* The presentation of **oligohydramnios**, **pulmonary hypoplasia**, and **enlarged, echogenic kidneys with multiple cysts** in a newborn is consistent with **autosomal recessive polycystic kidney disease (ARPKD)**.
* ARPKD is invariably associated with **congenital hepatic fibrosis**, which leads to **portal hypertension** due to periportal fibrosis and obstruction of intrahepatic portal blood flow. This is the hallmark extra-renal complication of ARPKD.
*Subarachnoid hemorrhage*
* Subarachnoid hemorrhage from berry aneurysm rupture is associated with **autosomal dominant polycystic kidney disease (ADPKD)**, not ARPKD.
* There are no specific clinical features or imaging findings in this case that would suggest intracranial hemorrhage as the highest risk complication.
*Acute renal failure*
* While neonates with ARPKD can develop renal insufficiency and progressive chronic kidney disease, the question asks for the "highest risk **complication**" rather than the primary disease manifestation.
* **Portal hypertension from congenital hepatic fibrosis** is the most significant distinct complication that develops as a consequence of ARPKD, often manifesting in childhood with hepatosplenomegaly, esophageal varices, and hypersplenism.
*Recurrent UTI*
* Recurrent UTIs require structural abnormalities like vesicoureteral reflux or urinary stasis, which are not primary features of ARPKD.
* While children with kidney disease may have increased infection risk, recurrent UTIs are not a direct or characteristic complication of the cystic kidney disease in ARPKD.
*Emphysema*
* **Pulmonary hypoplasia** (underdeveloped lungs from oligohydramnios/Potter sequence) is present in this case, but this is not the same as emphysema.
* Emphysema involves destruction of alveolar walls and is typically seen in adults with chronic obstructive pulmonary disease or alpha-1 antitrypsin deficiency, not in neonates with pulmonary hypoplasia.
Question 123: A 6-month-old boy is brought to the physician because of a right-sided scrotal swelling for the past 2 months. The swelling is intermittent and appears usually after the patient has been taken outdoors in a baby carrier, and disappears the next morning. The patient was born at term without complications and has been healthy. Examination shows a 3-cm, soft, nontender, and fluctuant right scrotal mass that is reducible and does not extend into the inguinal area. A light held behind the scrotum shines through. There are no bowel sounds in the mass. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in the management of this patient?
A. Reassurance and follow-up (Correct Answer)
B. Percutaneous drainage
C. Ligation of the patent processus vaginalis
D. Bilateral orchidopexy
E. Surgical excision of the mass
Explanation: ***Reassurance and follow-up***
- The presentation of an **intermittent, reducible, transilluminating scrotal swelling** in an infant, particularly one that resolves with rest, is characteristic of a **communicating hydrocele**.
- Most communicating hydroceles in infants resolve spontaneously by **12-18 months of age** as the **processus vaginalis** closes, so watchful waiting is the most appropriate initial management.
*Percutaneous drainage*
- This procedure is generally not recommended for communicating hydroceles due to the **risk of infection**, recurrence, and injury to scrotal structures.
- It does not address the underlying issue of the patent processus vaginalis, making it an ineffective long-term solution.
*Ligation of the patent processus vaginalis*
- This is the surgical treatment for a communicating hydrocele, but it is typically reserved for cases that **persist beyond 12-18 months of age** or those that cause complications.
- Given the patient's age (6 months) and the benign nature of the swelling, immediate surgical intervention is not indicated.
*Bilateral orchidopexy*
- **Orchidopexy** (surgical repositioning of a testis) is performed for **undescended testes**, which is not indicated by the patient's presentation.
- This patient has a scrotal swelling, and the testes are presumed to be in their normal position.
*Surgical excision of the mass*
- This is an overly aggressive and inappropriate intervention for a suspected communicating hydrocele.
- The mass is fluid-filled and caused by a patent processus vaginalis, not a solid tumor requiring excision.
Question 124: A 5-day-old boy is brought to see his pediatrician after his newborn blood screening showed elevated levels of immunoreactive trypsinogen, a marker for cystic fibrosis. The boy was born at 39 weeks gestation after regular prenatal care. He has 2 siblings that tested negative on screening. On physical exam, his vitals are normal and he appears healthy. Which of the following tests should be performed next to evaluate the newborn for cystic fibrosis?
A. Nasal potential difference
B. Intestinal current measurement
C. Measurement of fecal elastase levels
D. Mutation analysis
E. Sweat test (Correct Answer)
Explanation: ***Sweat test***
- A **sweat test** is the gold standard for diagnosing cystic fibrosis, measuring **chloride concentration** in sweat which is elevated in CF.
- Given the elevated **immunoreactive trypsinogen (IRT)** on newborn screening, a confirmatory diagnostic test like the sweat test is the appropriate next step.
*Nasal potential difference*
- **Nasal potential difference (NPD)** measures the electrical potential across the nasal epithelium, reflecting **CFTR channel function**.
- While used for CF diagnosis, it is typically employed in cases with **borderline sweat test results** or atypical presentations, not as a primary confirmatory test after positive newborn screening.
*Intestinal current measurement*
- **Intestinal current measurement (ICM)** assesses **chloride secretion** across the intestinal epithelium in response to secretagogues.
- This is a highly specialized research tool, generally not used in routine clinical diagnosis for confirming cystic fibrosis.
*Measurement of fecal elastase levels*
- **Fecal elastase levels** are used to assess **pancreatic exocrine function**, which is often impaired in cystic fibrosis.
- While relevant to CF, it primarily evaluates pancreatic involvement and is not the primary diagnostic test for CF itself following a positive newborn screen, but rather for assessing disease severity.
*Mutation analysis*
- **Mutation analysis** (genetic testing for **CFTR gene mutations**) can identify CF, especially if a sweat test is inconclusive or for screening purposes.
- Although useful, it's often done *after* a positive sweat test or when the sweat test is equivocal, as the **sweat test** remains the initial confirmatory diagnostic test after elevated IRT.
Question 125: A 4-month-old boy is brought by his mother to the pediatrician for a routine check-up. He was born at 39 weeks' gestation with a birth weight of 2.1 kg. Apgar scores were 6 and 8 at 1 and 5 minutes, respectively. The child has had feeding difficulties requiring supplemental feeding and frequent awakening at night. He has delayed developmental milestones and does not yet smile spontaneously. He is behind on his vaccination schedule due to frequent illnesses. His temperature is 98.6°F (37°C), blood pressure is 95/60 mmHg, pulse is 140/min, and respirations are 35/min. On physical examination, he has microcephaly, a prominent forehead, hypertelorism, a broad nasal bridge, and micrognathia. He also has hypotonia and is unable to hold his head steady when unsupported. This patient's condition is associated with a mutation in which of the following chromosomes?
A. 6
B. 4
C. 5
D. 7
E. 16 (Correct Answer)
Explanation: **Correct: 16**
- The patient's features, including **microcephaly**, prominent forehead, **hypertelorism**, broad nasal bridge, **micrognathia**, hypotonia, and developmental delay, are characteristic of **Rubinstein-Taybi syndrome**.
- Rubinstein-Taybi syndrome is caused by a mutation in the **CREBBP gene** located on chromosome **16p13.3**.
*Incorrect: 6*
- Abnormalities on chromosome 6 are associated with conditions like **hereditary hemochromatosis** or some forms of **epilepsy**, which do not match the presented clinical picture.
- The distinctive facial dysmorphisms and developmental delays seen in this patient are not characteristic features of chromosomal aberrations on chromosome 6.
*Incorrect: 4*
- Chromosome 4 abnormalities are associated with conditions such as **Huntington's disease** or **Wolf-Hirschhorn syndrome**.
- **Wolf-Hirschhorn syndrome** (4p-deletion) presents with a "Greek helmet" facies; however, the constellation of symptoms (e.g., prominent forehead, broad nasal bridge, micrognathia) doesn't fully align with the typical presentation of Wolf-Hirschhorn, and Rubinstein-Taybi is a more precise fit for these specific dysmorphic features.
*Incorrect: 5*
- Chromosome 5 abnormalities are linked to conditions like **Cri du Chat syndrome** (5p deletion) which is characterized by a high-pitched cry, microcephaly, and distinct facial features.
- While there is microcephaly in this case, the other specific facial features and absence of a characteristic cry make Cri du Chat less likely than Rubinstein-Taybi syndrome.
*Incorrect: 7*
- Chromosome 7 abnormalities are associated with conditions such as **Williams syndrome** (deletion on 7q11.23) or conditions involving **cystic fibrosis** (7q31.2).
- Williams syndrome involves an "elfin" facial appearance, outgoing personality, and cardiovascular anomalies, none of which are consistent with the patient's presentation.
Question 126: A 1-month-old infant is brought to the physician for a well-child examination. His mother reports that she had previously breastfed her son every 2 hours for 15 minutes but is now feeding him every 4 hours for 40 minutes. She says that the infant sweats a lot and is uncomfortable during feeds. He has 6 wet diapers and 2 stools daily. He was born at 36 weeks' gestation. He currently weighs 3500 g (7.7 lb) and is 52 cm (20.4 in) in length. He is awake and alert. His temperature is 37.1°C (98.8°F), pulse is 170/min, respirations are 55/min, and blood pressure is 80/60 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 99%. Cardiopulmonary examination shows a 4/6 continuous murmur along the upper left sternal border. After confirming the diagnosis via echocardiography, which of the following is the most appropriate next step in the management of this patient?
A. Digoxin and furosemide (Correct Answer)
B. Percutaneous surgery
C. X-ray of the chest
D. Prostaglandin E1 infusion
E. Indomethacin infusion
Explanation: ***Digoxin and furosemide***
- This 1-month-old infant presents with classic signs of **heart failure** from a symptomatic **patent ductus arteriosus (PDA)**: tachycardia (170/min), tachypnea (55/min), poor feeding with prolonged feeding times, diaphoresis during feeds, and a continuous murmur at the left upper sternal border.
- At **1 month of age**, the initial management focuses on **medical treatment of heart failure** with **furosemide** (loop diuretic to reduce volume overload) and **digoxin** (inotropic support to improve cardiac contractility).
- This stabilizes the infant before definitive closure is considered if medical management fails.
*Indomethacin infusion*
- **Indomethacin** (NSAID/prostaglandin inhibitor) is effective for **PDA closure only in premature infants within the first 7-14 days of life**.
- At **1 month of age** (approximately 40 weeks corrected gestational age), the ductus arteriosus is no longer responsive to prostaglandin inhibition, making indomethacin ineffective.
- This would have been appropriate if the infant was still in the early neonatal period.
*Percutaneous surgery*
- **Percutaneous transcatheter closure** or surgical ligation may be required if medical management of heart failure fails or the PDA remains hemodynamically significant.
- However, this is **not the initial step**—medical stabilization with heart failure management should be attempted first.
- Procedural closure is typically considered after 6 months of age if spontaneous closure has not occurred.
*X-ray of the chest*
- A chest X-ray would show **cardiomegaly** and **increased pulmonary vascular markings** consistent with the left-to-right shunt from PDA.
- However, the diagnosis has already been **confirmed by echocardiography**, and imaging does not constitute therapeutic management for this symptomatic infant.
*Prostaglandin E1 infusion*
- **Prostaglandin E1** is used to **maintain** ductal patency in **ductal-dependent congenital heart lesions** (e.g., critical coarctation, hypoplastic left heart syndrome, pulmonary atresia).
- In this case with symptomatic PDA, the goal is to manage heart failure and potentially achieve ductal closure, making PGE1 **contraindicated**.
Question 127: A 14-month-old boy has iron-deficiency anemia refractory to iron therapy. His stool is repeatedly positive for occult blood. The parents bring the child to the emergency room after they notice some blood in his stool. Which of the following is the diagnostic gold standard for this patient's most likely condition?
A. Colonoscopy
B. Technetium-99m pertechnetate scan (Correct Answer)
C. Capsule endoscopy
D. Abdominal CT with contrast
E. Tagged red blood cell study
Explanation: ***Technetium-99m pertechnetate scan***
- The clinical picture of **iron-deficiency anemia refractory to iron therapy**, **occult blood in the stool**, and visible blood in a 14-month-old strongly suggests a **Meckel's diverticulum** that contains ectopic gastric mucosa.
- This scan specifically detects **ectopic gastric mucosa**, which is the most common cause of bleeding from a Meckel's diverticulum, making it the **diagnostic gold standard**.
*Colonoscopy*
- While useful for evaluating the colon and rectum, **colonoscopy** is unlikely to identify a Meckel's diverticulum, which is located in the **small intestine**.
- It's primarily used for conditions like colonic polyps, inflammatory bowel disease, or lower gastrointestinal bleeding from the large bowel.
*Capsule endoscopy*
- **Capsule endoscopy** can visualize the small bowel mucosa and detect bleeding, but it does not specifically identify **ectopic gastric mucosa** and may miss a Meckel's diverticulum, especially if it's not actively bleeding at the time of the study.
- It is also less commonly used in very young children due to issues with capsule passage and retention.
*Abdominal CT with contrast*
- An **abdominal CT with contrast** can identify some structural abnormalities and inflammation but is generally not the primary diagnostic tool for a Meckel's diverticulum.
- It has **limited sensitivity** for detecting ectopic gastric mucosa or the diverticulum itself, particularly if it's small or not inflamed.
*Tagged red blood cell study*
- A **tagged red blood cell study** can detect the site of active gastrointestinal bleeding, but it does not identify the **underlying cause** of the bleeding, such as a Meckel's diverticulum.
- It requires active bleeding at a rate of at least 0.1 mL/min to be positive, and may be less specific than a Meckel's scan for this particular pathology.
Question 128: A 31-year-old woman delivers a healthy boy at 38 weeks gestation. The delivery is vaginal and uncomplicated. The pregnancy was unremarkable. On examination of the newborn, it is noted that his head is tilted to the left and his chin is rotated to the right. Palpation reveals no masses or infiltration in the neck. The baby also shows signs of left hip dysplasia. Nevertheless, the baby is active and exhibits no signs of other pathology. What is the most probable cause of this patient's condition?
A. Basal ganglia abnormalities
B. Antenatal trauma
C. Congenital infection
D. Accessory nerve palsy
E. Intrauterine malposition (Correct Answer)
Explanation: ***Intrauterine malposition***
- The combination of **congenital muscular torticollis** (head tilted left, chin rotated right) and **hip dysplasia** in a newborn strongly suggests **intrauterine confinement**.
- **Malposition** *in utero* can restrict fetal movement and lead to musculoskeletal abnormalities due to prolonged pressure on developing structures.
*Basal ganglia abnormalities*
- **Basal ganglia abnormalities** typically present with movement disorders such as dyskinesias, dystonia, or rigidity, often without the specific musculoskeletal findings described.
- While they can cause abnormal posturing, the concurrent **hip dysplasia** points away from a primary neurological cause.
*Antenatal trauma*
- **Antenatal trauma** (trauma occurring during pregnancy before labor) severe enough to cause these musculoskeletal findings would typically require significant force and would likely present with other signs of injury or complications during pregnancy.
- The **unremarkable pregnancy** and **uncomplicated delivery** make trauma an unlikely cause.
- These findings are better explained by chronic positional constraint rather than acute traumatic injury.
*Congenital infection*
- **Congenital infections** such as TORCH infections usually present with a broader range of symptoms including systemic illness, neurological impairments (e.g., microcephaly, seizures), or specific organ damage.
- The isolated musculoskeletal findings of torticollis and hip dysplasia, without other signs, are not characteristic of a congenital infection.
*Accessory nerve palsy*
- **Accessory nerve palsy** would primarily affect the **sternocleidomastoid** and **trapezius muscles**, leading to weakness and potentially torticollis.
- However, it would not explain the associated **hip dysplasia**, making it an incomplete diagnosis for the overall presentation.
Question 129: Over the course of a year, 5 children with identical congenital heart defects were referred to a pediatric cardiac surgeon for evaluation. All 5 children had stable vital signs and were on appropriate medication. Upon review of medical records, all of them had a loud holosystolic murmur over the third intercostal space at the left sternal border. The surgeon ordered echocardiograms for all 5 children and recommended surgical closure of the defect in one of them. Which of the following patients required surgical repair of their defect?
A. A 7-year-old boy with an 11-mm muscular defect and severe pulmonary vascular disease non-responsive to pulmonary vasodilators
B. An 11-month-old female infant with a 6-mm membranous defect, without heart failure, pulmonary hypertension, or growth failure
C. A 4-month-old male infant with a 12-mm muscular defect, without heart failure, pulmonary hypertension or growth failure
D. A 5-year-old girl with a 2-mm membranous defect, no heart failure, a Qp:Qs ratio less than 2:1, and no growth failure
E. A 2-year-old boy with a 2-mm supracristal defect, without heart failure, pulmonary hypertension, or growth failure (Correct Answer)
Explanation: ***A 2-year-old boy with a 2-mm supracristal defect, without heart failure, pulmonary hypertension, or growth failure***
- This patient description most closely matches the criteria for requiring surgical repair. **Supracristal VSDs** are more prone to **aortic valve prolapse** and **aortic regurgitation**, even with small defects and absent or mild symptoms, thus warranting early surgical consideration.
- While other symptomatic VSDs might require surgery, this specific type of VSD carries a unique risk to the aortic valve, making surgical intervention often necessary to prevent future complications.
*A 7-year-old boy with an 11-mm muscular defect and severe pulmonary vascular disease non-responsive to pulmonary vasodilators*
- This patient likely has **Eisenmenger syndrome**, characterized by **irreversible pulmonary vascular disease** and right-to-left shunting.
- Surgical repair of the VSD is **contraindicated** in such cases and would likely worsen the patient's condition.
*An 11-month-old female infant with a 6-mm membranous defect, without heart failure, pulmonary hypertension, or growth failure*
- Small to moderate membranous VSDs in asymptomatic infants often **close spontaneously**, especially in the first year of life.
- Without signs of **heart failure**, **pulmonary hypertension**, or **growth failure**, a watch-and-wait approach is typically preferred over immediate surgery.
*A 4-month-old male infant with a 12-mm muscular defect, without heart failure, pulmonary hypertension or growth failure*
- Although this is a **large muscular VSD**, the infant is currently **asymptomatic** without heart failure, pulmonary hypertension, or growth failure.
- In the **absence of symptoms or hemodynamic compromise**, initial management includes close observation with medical therapy as needed. Surgery would be indicated if symptoms develop or significant shunting occurs.
- Note: While small muscular VSDs (<5mm) often close spontaneously, large defects like this require vigilant monitoring as they may eventually require intervention.
*A 5-year-old girl with a 2-mm membranous defect, no heart failure, a Qp:Qs ratio less than 2:1, and no growth failure*
- A 2-mm membranous defect is considered a **small VSD**, and a Qp:Qs ratio less than 2:1 indicates an **insignificant shunt**.
- Small VSDs, particularly in older children who are asymptomatic, very often close spontaneously or remain hemodynamically insignificant, and typically do not require surgical intervention.
Question 130: A 7-year-old girl presents with a lump in her neck which she noticed a few days ago. The patient's mother states that her daughter's left eyelid seems to be drooping, making her left eye look small. There is no significant past medical history. On neurological examination, the patient has normal bilateral pupillary reflexes but a miotic left pupil. A lateral radiograph of the chest reveals a mass in the posterior mediastinum with no evidence of bone erosion. An MRI is performed and the results are shown in the image. An imaging-guided biopsy of the mass reveals spindle-shaped cells arranged chaotically, with moderate cytoplasm and small nuclei. Scattered mature ganglion cells with abundant cytoplasm and round to oval nuclei are also present. The biopsy tissue is analyzed with immunohistochemistry and found to be positive for S-100, synaptophysin, and chromogranin. Which of the following factors is associated with poor prognosis for this patient's most likely diagnosis?
A. Absence of nodular pattern
B. Absence of MYCN gene amplification
C. Detectable levels of homovanillic acid (HVA) and/or vanillylmandelic acid (VMA) in urine
D. Age younger than 18 months
E. Deletion of short arm of chromosome 1 (Correct Answer)
Explanation: ***Deletion of short arm of chromosome 1***
- **Deletion of the short arm of chromosome 1 (1p deletion)** is a common genetic abnormality found in neuroblastoma and is consistently associated with a **poor prognosis**, indicating aggressive disease.
- This genetic alteration is often correlated with other high-risk features, such as **MYCN amplification**, and is a critical factor in risk stratification for treatment planning.
*Absence of nodular pattern*
- The **absence of a nodular pattern** in ganglioneuroblastoma or ganglioneuroma indicates more favorable, mature differentiation. Nodularity, especially in younger patients with immature components, can suggest more aggressive neuroblastoma with poorer outcomes.
- The biopsy here describes mature ganglion cells and spindle cells, consistent with a more differentiated tumor.
*Absence of MYCN gene amplification*
- The **absence of MYCN gene amplification** is a favorable prognostic indicator in neuroblastoma, *not* a poor one. MYCN amplification is strongly associated with aggressive tumor behavior, rapid progression, and poor clinical outcomes.
*Detectable levels of homovanillic acid (HVA) and/or vanillylmandelic acid (VMA) in urine*
- **Detectable levels of HVA and/or VMA** in urine are metabolic markers of catecholamine production, elevated in most neuroblastomas due to the tumor's origin from neural crest cells.
- While their presence aids in diagnosis, detectability alone is not a poor prognostic factor. Very high levels or failure to normalize after treatment can indicate worse prognosis, but simple detectability is expected in these tumors.
*Age younger than 18 months*
- **Age younger than 18 months** at diagnosis is generally considered a **favorable prognostic factor** for neuroblastoma, especially in localized disease.
- Younger patients often have better outcomes, even with advanced-stage disease, possibly due to a higher likelihood of spontaneous regression or maturation of the tumor. This patient's age of 7 years is actually an unfavorable prognostic factor.
