Congenital Anomalies Overview — MCQs

10 questions

Which of the following statements about encephalocoele is false?

What is the most common site of congenital diaphragmatic hernia?

A newborn male is noted to have difficulty feeding and "turns blue and chokes when drinking formula." The prenatal records reveal that the amniotic fluid appeared normal on ultrasound. A pediatric feeding tube is passed orally to 20 cm without difficulty, with gastric secretions aspirated. Which of the following is the most likely diagnosis?

A woman presents with painless ulcers on the vulva, she gives a history of having multiple sexual partners and has had a stillbirth at 28 weeks in the past. What is the next best step of investigation?

Which one of the following life-threatening congenital anomalies in the newborn presents with polyhydramnios, aspiration pneumonia, excessive salivation and difficulty in passing a nasogastric tube?

Banana sign is seen in which of the following conditions?

Which of the following STDs causes fetal abnormality?

A 3-month-old infant presents with an abdominal palpable mass and non-bilious vomiting. What is the most likely diagnosis?

True about congenital diaphragmatic hernia (CDH) except:

Q10

In Congenital Diaphragmatic Hernia (CDH), the most commonly associated anomaly affects the

Congenital Anomalies Overview Indian Medical PG Practice Questions and MCQs

Question 1: Which of the following statements about encephalocoele is false?

A. It is a neural tube defect
B. Common in the parietal region (Correct Answer)
C. Can be associated with hydrocephalus
D. It is protrusion of neural tissue through a defect

Explanation: ***Common in the parietal region*** - This statement is **false** because encephaloceles are **rarely found in the parietal region** (only 10-15% of cases). - **Occipital encephaloceles** are most common in Western populations (75-80%), while **frontal/sincipital encephaloceles** are most common in Southeast Asia including India (40-60%). - **Parietal encephaloceles** represent only a small minority of cases globally, making this statement incorrect. *It is a neural tube defect* - **Encephalocele** is indeed a type of **neural tube defect (NTD)**, resulting from incomplete closure of the neural tube during embryonic development. - Specifically, it involves a defect in the skull that allows for protrusion of brain tissue and/or meninges. *Can be associated with hydrocephalus* - **Hydrocephalus**, or the accumulation of cerebrospinal fluid in the brain, is a known complication and associated condition with encephaloceles. - The abnormal brain development and structural defects can disrupt normal CSF flow and absorption, particularly with posterior encephaloceles. *It is protrusion of neural tissue through a defect* - This is the defining characteristic of an **encephalocele**: the **herniation of intracranial contents**, such as brain tissue, meninges, or both, through a congenital **bony defect** in the skull. - The contents of the sac can vary (meninges only = meningocele; brain tissue included = meningoencephalocele), influencing clinical presentation and prognosis.

Question 2: What is the most common site of congenital diaphragmatic hernia?

A. Central tendon
B. Posterolateral (Correct Answer)
C. Crural
D. Anterolateral
E. Esophageal hiatus

Explanation: ***Posterolateral*** - The **posterolateral** region, specifically the foramen of Bochdalek, is the most common site for congenital diaphragmatic hernia (CDH). - This type of hernia accounts for approximately 80-90% of all CDH cases and usually occurs on the **left side**. *Central tendon* - Hernias through the **central tendon** are extremely rare and are distinct from the more common forms of CDH. - Defects in the central tendon are often associated with **pericardial defects** rather than typical diaphragmatic hernias which allow abdominal contents into the thoracic cavity. *Crural* - Hernias involving the **crura** of the diaphragm are typically **hiatal hernias** (e.g., sliding or paraesophageal), which are different in origin and presentation from CDH. - These are usually acquired and involve the stomach moving into the mediastinum, rather than a congenital defect leading to abdominal viscera migrating into the chest. *Anterolateral* - While congenital diaphragmatic hernias can occur **anterolaterally** through the foramen of Morgagni, these are much less common than posterolateral hernias. - Morgagni hernias account for a small percentage of CDH cases (around 2-5%) and are typically located on the right side, often containing omentum or colon. *Esophageal hiatus* - The **esophageal hiatus** is the normal opening in the diaphragm through which the esophagus passes. - While hiatal hernias can occur at this site, these are typically **acquired hernias** in adults, not congenital diaphragmatic hernias. - Congenital CDH refers to developmental defects in the diaphragm itself, not enlargement of normal openings.

Question 3: A newborn male is noted to have difficulty feeding and "turns blue and chokes when drinking formula." The prenatal records reveal that the amniotic fluid appeared normal on ultrasound. A pediatric feeding tube is passed orally to 20 cm without difficulty, with gastric secretions aspirated. Which of the following is the most likely diagnosis?

A. Floppy epiglottis
B. Tracheoesophageal fistula (Correct Answer)
C. Zenker diverticulum
D. Congenital heart disease

Explanation: ***Tracheoesophageal fistula*** - The combination of **feeding difficulties**, **cyanosis** ("turns blue"), and **choking** in a newborn, along with the ability to pass a feeding tube to 20 cm, strongly suggests a tracheoesophageal fistula (TEF), specifically a type where the **proximal esophagus ends in a blind pouch and the distal esophagus connects to the trachea**. - The **normal amniotic fluid** on prenatal ultrasound suggests that the fetus was able to swallow amniotic fluid, ruling out esophageal atresia without a fistula as the primary cause of polyhydramnios. Passage of the feeding tube to 20 cm and aspiration of gastric secretions indicates that the stomach is connected to the esophagus, but the reflux of gastric contents during feeding leads to aspiration into the trachea via the fistula. *Floppy epiglottis* - **Laryngomalacia**, or "floppy epiglottis," typically causes **stridor** (a high-pitched inspiratory sound), especially when crying or feeding, which is not the primary symptom described here. - While it can cause some feeding difficulties, **severe cyanosis and recurrent choking** during feeding are more characteristic of aspiration due to a different anatomical defect like TEF. *Zenker diverticulum* - A **Zenker diverticulum is a pharyngoesophageal pouch** that typically causes dysphagia, regurgitation of undigested food, and halitosis, primarily in **older adults**. - It is an acquired condition and **extremely rare in newborns**, making it an unlikely diagnosis for these symptoms in an infant. *Congenital heart disease* - While congenital heart disease can cause **cyanosis and feeding difficulties** due to increased metabolic demand or heart failure, it would not typically present with the specific description of **choking during feeding and successful passing of a feeding tube to the stomach with aspirated gastric secretions**. - The symptoms in this case point more directly to a **problem with the swallowing mechanism or the connection between the esophagus and the trachea**.

Question 4: A woman presents with painless ulcers on the vulva, she gives a history of having multiple sexual partners and has had a stillbirth at 28 weeks in the past. What is the next best step of investigation?

A. PCR
B. VDRL (Correct Answer)
C. Vaginal swab and culture
D. NAT

Explanation: ***VDRL*** - The presentation of **painless vulvar ulcers**, a history of **multiple sexual partners**, and a past **stillbirth at 28 weeks** are highly suggestive of **syphilis**. - A **VDRL (Venereal Disease Research Laboratory) test** is a non-treponemal serologic test used for screening and monitoring the treatment of syphilis. *PCR* - While **PCR** can be used to detect the genetic material of *Treponema pallidum*, it is not the primary diagnostic test for syphilis, especially given the classic clinical picture. - It is more commonly used for detecting other sexually transmitted infections (STIs) or for specific situations where direct detection of the organism from a lesion is preferred. *Vaginal swab and culture* - A **vaginal swab and culture** would be appropriate for diagnosing bacterial vaginosis, candidiasis, or certain bacterial STIs, but it is not suitable for diagnosing syphilis. - Syphilis is caused by a spirochete (*Treponema pallidum*) that cannot be cultured on standard media. *NAT* - **Nucleic Acid Amplification Tests (NATs)** are a broad category of tests that include PCR. - Like PCR, while potentially applicable for *Treponema pallidum* detection, they are not the standard or first-line diagnostic investigation for syphilis given the strong clinical indicators.

Question 5: Which one of the following life-threatening congenital anomalies in the newborn presents with polyhydramnios, aspiration pneumonia, excessive salivation and difficulty in passing a nasogastric tube?

A. Choanal atresia
B. Gastroschisis
C. Diaphragmatic hernia
D. Tracheo-esophageal fistula (Correct Answer)

Explanation: ***Tracheo-esophageal fistula*** - This condition presents with **polyhydramnios** due to the fetus being unable to swallow amniotic fluid, **excessive salivation** from accumulated secretions in the blind-ending esophageal pouch, and difficulty passing a **nasogastric tube** because of the esophageal obstruction. - **Aspiration pneumonia** is a common complication as saliva and gastric contents can be aspirated into the lungs through the fistula. *Choanal atresia* - Characterized by **blocked nasal passages**, leading to **cyclical cyanosis** relieved by crying, but not typically associated with polyhydramnios or excessive salivation in this manner. - While it can cause respiratory distress, it does not involve esophageal obstruction or directly cause aspiration pneumonia from swallowed fluids. *Gastroschisis* - This is an **abdominal wall defect** where intestines protrude outside the body, unrelated to swallowing difficulties, polyhydramnios caused by inability to swallow, or excessive salivation. - It does not involve difficulty in passing a nasogastric tube or directly cause aspiration pneumonia. *Diaphragmatic hernia* - Involves **abdominal contents herniating into the chest cavity**, leading to **pulmonary hypoplasia** and respiratory distress. - It does not explain polyhydramnios due to impaired swallowing, excessive salivation, or the characteristic inability to pass a nasogastric tube.

Question 6: Banana sign is seen in which of the following conditions?

A. NCC
B. Spina bifida (Correct Answer)
C. Omphalocele
D. Anencephaly

Explanation: ***Spina bifida*** - The **"banana sign"** is a distinctive ultrasound finding associated with **Chiari II malformation**, which is frequently seen in cases of **spina bifida**. - It refers to the characteristic **flattening and anterior bowing of the cerebellar hemispheres**, compressing them against the skull and giving them a banana-like appearance. *NCC* - **Neurocysticercosis (NCC)** is caused by tapeworm larvae in the central nervous system and is characterized by **cysts** or calcifications on imaging, not a "banana sign." - Imaging findings in NCC typically include **cystic lesions**, **edema**, and calcifications, unrelated to cerebellar shape. *Omphalocele* - **Omphalocele** is an abdominal wall defect where abdominal organs protrude through the navel, covered by a membrane. - The ultrasound findings for omphalocele involve visualization of abdominal contents outside the abdominal cavity, which is distinct from intracranial findings like the "banana sign." *Anencephaly* - **Anencephaly** is a severe birth defect where a baby is born without parts of the brain and skull, typically presenting with an **absent cranial vault** and cerebral hemispheres. - While a severe neural tube defect, anencephaly features agenesis of the brain and skull, rather than the cerebellar distortion seen as a "banana sign."

Question 7: Which of the following STDs causes fetal abnormality?

A. Syphilis (Correct Answer)
B. Herpes
C. Gonorrhea
D. Hepatitis B

Explanation: ***Syphilis*** - **Congenital syphilis**, resulting from maternal infection, can lead to severe fetal abnormalities such as **bone deformities**, **saddle nose**, **Hutchinson's teeth**, and **neurological problems**. - It can also cause stillbirth, prematurity, or hydrops fetalis, emphasizing the importance of early detection and treatment during pregnancy. *Herpes* - While **neonatal herpes** can be life-threatening and cause neurological damage, it is typically acquired during passage through the birth canal and does not cause **fetal abnormalities** during gestation. - Herpes simplex virus primarily causes localized lesions and systemic infection in the neonate, not developmental defects. *Gonorrhea* - Gonorrhea primarily causes **ophthalmia neonatorum** (conjunctivitis) in newborns through exposure during birth, which can lead to blindness if untreated. - It does not typically cause **fetal abnormalities** or congenital defects through transplacental transmission. *Hepatitis B* - Hepatitis B can be transmitted to the fetus during birth, leading to **chronic hepatitis B infection** in the infant. - Although it causes a chronic disease, it does not typically result in **fetal abnormalities** or congenital malformations.

Question 8: A 3-month-old infant presents with an abdominal palpable mass and non-bilious vomiting. What is the most likely diagnosis?

A. Hypertrophic pyloric stenosis (Correct Answer)
B. Tracheoesophageal fistula
C. Duodenal atresia
D. Intussusception

Explanation: ***Hypertrophic pyloric stenosis*** - The classic presentation includes **projectile non-bilious vomiting** and a palpable **olive-shaped mass** in the epigastrium of an infant typically between 3 weeks and 6 months of age. - The vomiting is non-bilious because the obstruction is proximal to the ampulla of Vater. *Intussusception* - While it can present with an **abdominal mass** and vomiting, the vomiting is often **bilious** and the classic stool is **'currant jelly'**, which is not mentioned here. - It usually presents with sudden onset of severe, **colicky abdominal pain** and occurs more commonly in slightly older infants (6-12 months). *Tracheoesophageal fistula* - This condition presents at birth with symptoms such as **choking, coughing**, and **cyanosis** during feeding. - It usually causes respiratory distress and feeding difficulties from the first days of life, not a palpable abdominal mass and non-bilious vomiting at 3 months. *Duodenal atresia* - This is a congenital obstruction that typically presents with **bilious vomiting** (as the obstruction is distal to the ampulla of Vater) within the first 24-48 hours of life. - Imaging usually shows a **“double bubble” sign** on abdominal X-ray, and an abdominal mass is not typically palpable.

Question 9: True about congenital diaphragmatic hernia (CDH) except:

A. Causes pulmonary hypoplasia
B. Occurs mostly on the left side
C. Occurs anteriorly in the diaphragm (Correct Answer)
D. Leads to cyanosis at birth

Explanation: ***Occurs anteriorly in the diaphragm*** - Congenital diaphragmatic hernias (CDH) typically occur through the **foramen of Bochdalek**, which is a posterolateral defect in the diaphragm. - Herniations through the **foramen of Morgagni** are anterior, but these are far less common than Bochdalek hernias (only 2-3% of cases). *Causes pulmonary hypoplasia* - The presence of abdominal organs in the thoracic cavity during fetal development **compresses the developing lungs**, leading to underdevelopment. - This results in **reduced lung volume** and **abnormal pulmonary vasculature**. *Occurs mostly on the left side* - Approximately **80-85% of CDH cases are left-sided**, possibly due to the protective effect of the liver on the right side. - The left pleuroperitoneal canal typically closes later than the right side, making it more susceptible to defects. *Leads to cyanosis at birth* - **Pulmonary hypoplasia** and **persistent pulmonary hypertension** result in right-to-left shunting of blood, causing severe hypoxia and cyanosis. - Infants often present with acute respiratory distress, cyanosis, and scaphoid abdomen soon after birth.

Question 10: In Congenital Diaphragmatic Hernia (CDH), the most commonly associated anomaly affects the

A. Congenital heart defects (Correct Answer)
B. Anomalies of the urinary tract
C. Anomalies of the skull
D. Craniofacial anomalies

Explanation: ***Congenital heart defects*** - **Congenital diaphragmatic hernia (CDH)** is frequently associated with other congenital anomalies. - **Cardiac malformations** are the most common co-occurring defects, affecting a significant proportion of CDH patients. *Anomalies of the urinary tract* - While **urogenital anomalies** can occur with CDH, they are less prevalent than congenital heart defects. - These typically include conditions like **renal agenesis** or **hydronephrosis**. *Anomalies of the skull* - **Skull anomalies** are not a primary or common association with congenital diaphragmatic hernia. - Genetic syndromes associated with both CDH and skull anomalies are relatively rare. *Craniofacial anomalies* - **Craniofacial anomalies**, such as **cleft lip/palate**, can occur with CDH but are less common than cardiac anomalies. - These are often seen within the context of specific genetic syndromes.

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