Congenital abdominal wall defects US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Congenital abdominal wall defects. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Congenital abdominal wall defects US Medical PG Question 1: A 4-week-old infant is brought to the emergency department by his parents with violent vomiting. It started about 3 days ago and has slowly gotten worse. He vomits after most feedings but seems to keep some formula down. His mother notes that he is eager to feed between episodes and seems to be putting on weight. Other than an uncomplicated course of chlamydia conjunctivitis, the infant has been healthy. He was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. The physical exam is significant for a palpable mass in the right upper quadrant. What is the first-line confirmatory diagnostic test and associated finding?
- A. Abdominal ultrasound; elongated pyloric channel and muscle hypertrophy (Correct Answer)
- B. Barium upper GI series; GE junction and portion of the stomach in thorax
- C. Air enema; filling defect and coil spring sign
- D. Barium upper GI series; bird beak sign and corkscrewing
- E. Abdominal X-ray; ‘double bubble’ sign
Congenital abdominal wall defects Explanation: ***Abdominal ultrasound; elongated pyloric channel and muscle hypertrophy***
- The clinical picture of **projectile vomiting** in a 4-week-old infant, **eagerness to feed** ("hungry vomiter"), and **palpable olive-shaped mass** in the right upper quadrant is classic for **pyloric stenosis**.
- **Abdominal ultrasonography** is the gold standard for diagnosis, revealing an **elongated pyloric channel** (>16mm) and thickened pyloric muscle (>3-4mm).
- Pyloric stenosis typically presents between 3-6 weeks of age with progressive non-bilious vomiting.
*Barium upper GI series; GE junction and portion of the stomach in thorax*
- A **barium upper GI series** showing the **GE junction and stomach in the thorax** would indicate a **hiatal hernia**, which is not consistent with the palpable mass or "hungry vomiter" presentation.
- While hiatal hernias can cause vomiting and reflux, they typically don't present with this specific type of projectile vomiting or a palpable abdominal mass.
*Air enema; filling defect and coil spring sign*
- An **air enema** showing a **filling defect** and **coil spring sign** is characteristic of **intussusception**, which usually presents with sudden onset of **crampy abdominal pain**, **currant jelly stools**, and a palpable mass in the right lower quadrant.
- The clinical presentation does not fit intussusception, which typically occurs in older infants (6-36 months) and has a more acute presentation.
*Barium upper GI series; bird beak sign and corkscrewing*
- A **barium upper GI series** showing a **bird beak sign** and **corkscrewing** is pathognomonic for **midgut volvulus**, a surgical emergency.
- While volvulus can cause bilious vomiting and abdominal distension, the presentation of non-bilious vomiting with a palpable pyloric mass is more typical of pyloric stenosis.
*Abdominal X-ray; 'double bubble' sign*
- An **abdominal X-ray** revealing a **'double bubble' sign** is indicative of **duodenal atresia** or **annular pancreas**, leading to complete duodenal obstruction.
- This condition typically presents with **bilious vomiting** shortly after birth (within first day of life) and does not involve a palpable hypertrophied pylorus.
Congenital abdominal wall defects US Medical PG Question 2: A research team is studying certain congenital anomalies of the respiratory tract. The method consists of marking a certain germinal layer with an isotope, following its development stages in chicken embryos, and finally analyzing the specimen. A given specimen of tissue is presented in the exhibit. Which of the following germinal structures most likely gave rise to the epithelial lining of this specimen?
- A. Ectoderm
- B. Neural crest
- C. Mesoderm
- D. Endoderm (Correct Answer)
- E. Surface ectoderm
Congenital abdominal wall defects Explanation: ***Endoderm***
- The **epithelial lining** of the entire respiratory tract, including the larynx, trachea, bronchi, and lungs, is derived from the **endoderm**.
- The **laryngotracheal groove** develops from the ventral wall of the primitive foregut, which is endodermal in origin, further differentiating into the respiratory tree.
*Ectoderm*
- The **ectoderm** primarily forms the epidermis, hair, nails, and the nervous system (brain and spinal cord).
- It does not contribute to the internal epithelial lining of the respiratory tract.
*Neural crest*
- **Neural crest cells** contribute to a wide variety of structures, including components of the peripheral nervous system, head mesenchyme, and melanocytes.
- They are not involved in forming the epithelial lining of the respiratory system.
*Mesoderm*
- The **mesoderm** forms the connective tissue, cartilage, and muscle components of the respiratory tract, such as the smooth muscle and cartilage rings of the trachea and bronchi, and the visceral pleura.
- However, it does not form the epithelial lining itself.
*Surface ectoderm*
- **Surface ectoderm** specifically gives rise to the epidermis, hair, nails, and glands of the skin, as well as the oral cavity epithelium.
- It does not contribute to the internal epithelial structures of the respiratory tract.
Congenital abdominal wall defects US Medical PG Question 3: A 52-year-old man comes to the physician because of a 3-month history of upper abdominal pain and nausea that occurs about 3 hours after eating and at night. These symptoms improve with eating. After eating, he often has a feeling of fullness and bloating. He has had several episodes of dark stools over the past month. He has smoked one pack of cigarettes daily for 40 years and drinks 2 alcoholic beverages daily. He takes no medications. His temperature is 36.4°C (97.5°F), pulse is 80/min, and blood pressure is 110/70 mm Hg. Abdominal examination shows epigastric tenderness with no guarding or rebound. Bowel sounds are normal. Which of the following treatments is most appropriate to prevent further complications of the disease in this patient?
- A. Intravenous vitamin B12 supplementation
- B. Truncal vagotomy
- C. Amoxicillin, clarithromycin, and omeprazole (Correct Answer)
- D. Fundoplication, hiatoplasty, and gastropexy
- E. Distal gastrectomy with gastroduodenostomy
Congenital abdominal wall defects Explanation: ***Amoxicillin, clarithromycin, and omeprazole***
- This patient's symptoms (epigastric pain 3 hours after eating and at night, improvement with eating, dark stools) are highly suggestive of a **duodenal ulcer complicated by upper gastrointestinal bleeding**. The most common cause of duodenal ulcers is *H. pylori* infection.
- The recommended first-line treatment for *H. pylori* infection involves a triple therapy regimen, including two antibiotics (like **amoxicillin and clarithromycin**) to eradicate the bacteria and a **proton pump inhibitor (omeprazole)** to reduce acid production and promote ulcer healing.
*Intravenous vitamin B12 supplementation*
- This treatment is appropriate for **vitamin B12 deficiency**, which can occur in conditions like atrophic gastritis, pernicious anemia, or following gastric resections, but is not indicated for acute peptic ulcer disease and wouldn't address the primary pathology.
- There is no clinical indication in the patient's presentation (e.g., neurological symptoms, macrocytic anemia) to suggest a deficiency in vitamin B12.
*Truncal vagotomy*
- **Truncal vagotomy** is a surgical procedure that was historically performed to reduce gastric acid secretion by cutting the vagus nerve. It is rarely used now due to the effectiveness of medical therapies for peptic ulcer disease.
- This invasive surgical option is generally reserved for refractory cases of peptic ulcer disease not responsive to medical management, or when complications like uncontrolled bleeding or perforation necessitate surgical intervention.
*Fundoplication, hiatoplasty, and gastropexy*
- These surgical procedures are primarily used to treat **gastroesophageal reflux disease (GERD)** and **hiatal hernia**, not peptic ulcer disease.
- Fundoplication wraps the stomach fundus around the lower esophagus to reinforce the lower esophageal sphincter, addressing reflux symptoms which are not the primary complaint here.
*Distal gastrectomy with gastroduodenostomy*
- **Distal gastrectomy** is a major surgical procedure involving the removal of the distal part of the stomach. It is typically reserved for severe complications of peptic ulcer disease (e.g., perforation, obstruction, recurrent bleeding unresponsive to other treatments) or gastric cancer.
- While it might be considered in extreme cases of complicated peptic ulcer, it is not the initial or most appropriate treatment for preventing further complications in a patient who has yet to receive standard anti-*H. pylori* therapy.
Congenital abdominal wall defects US Medical PG Question 4: A 4700-g (10.3-lb) male newborn is delivered at 37 weeks' gestation to a 30-year-old woman, gravida 2, para 1. Apgar scores are 7 and 8 at 1 and 5 minutes, respectively. The newborn appears pale. Temperature is 37°C (98.6°F), pulse is 180/min, and blood pressure is 90/60 mm Hg. Examination in the delivery room shows midfacial hypoplasia, infraorbital creases, and a large tongue. The right side of the body is larger than the left. Abdominal examination shows that the abdominal viscera protrudes through the abdominal wall at the umbilicus; the viscera are covered by the amniotic membrane and the peritoneum. The liver is palpated 2–3 cm below the right costal margin. Fingerstick blood glucose concentration is 60 mg/dL. Ultrasonography of the abdomen shows enlarged kidneys bilaterally. In addition to surgical closure of the abdominal wall, which of the following is the most appropriate next step in management?
- A. Serum 17-hydroxyprogesterone measurement
- B. Serum TSH measurement
- C. Serum IGF-1 measurement
- D. Cranial MRI
- E. Serial abdominal ultrasonography (Correct Answer)
Congenital abdominal wall defects Explanation: ***Serial abdominal ultrasonography***
- The combination of **macrosomia**, **omphalocele**, **hemihyperplasia**, **visceromegaly** (large kidneys and liver), **macroglossia** (large tongue), and **facial anomalies** is highly suggestive of **Beckwith-Wiedemann Syndrome (BWS)**.
- Children with BWS have an increased risk of developing specific **embryonal tumors**, including **Wilms tumor** and **hepatoblastoma**, making regular abdominal ultrasonography crucial for early detection.
- **Current guidelines recommend abdominal ultrasound every 3 months until age 8** for tumor surveillance.
- Note: The mild hypoglycemia (60 mg/dL) should be monitored, as neonatal hypoglycemia is common in BWS, but tumor surveillance is the critical long-term management priority.
*Serum 17-hydroxyprogesterone measurement*
- This test is used to screen for **congenital adrenal hyperplasia (CAH)**.
- The clinical presentation does not suggest CAH, as there are no signs of **ambiguous genitalia** or **salt-wasting crisis**.
*Serum TSH measurement*
- **Thyroid-stimulating hormone (TSH)** is measured to screen for **congenital hypothyroidism**.
- While lethargy and feeding difficulties can occur in hypothyroidism, the described constellation of anomalies, especially macrosomia and omphalocele, is not characteristic of this condition.
*Serum IGF-1 measurement*
- **Insulin-like growth factor 1 (IGF-1)** levels are primarily evaluated in cases of suspected **growth hormone deficiency** or **excess (gigantism/acromegaly)**.
- While BWS involves overgrowth, the initial diagnostic and screening approach for associated tumor risk does not involve IGF-1 measurement.
*Cranial MRI*
- **Cranial MRI** is indicated for neurological symptoms or suspected brain anomalies.
- The patient's presentation does not include any neurological deficits or signs suggesting intracranial pathology as the primary concern.
Congenital abdominal wall defects US Medical PG Question 5: A 19-year-old woman, gravida 1, para 0, at 21 weeks’ gestation comes to the physician for a follow-up prenatal visit. At her previous appointment, her serum α-fetoprotein concentration was elevated. She had smoked 1 pack of cigarettes daily for 3 years but quit at 6 weeks' gestation. Examination shows a uterus consistent in size with a 21-week gestation. Ultrasonography shows fetal viscera suspended freely into the amniotic cavity. Which of the following is the most likely diagnosis?
- A. Omphalocele
- B. Vesicourachal diverticulum
- C. Umbilical hernia
- D. Gastroschisis (Correct Answer)
- E. Diaphragmatic hernia
Congenital abdominal wall defects Explanation: ***Gastroschisis***
- This condition is characterized by **fetal viscera suspended freely into the amniotic cavity**, indicating an abdominal wall defect where organs are exposed directly.
- **Elevated maternal serum α-fetoprotein (MSAFP)** is a classic finding in gastroschisis due to the direct exposure of fetal blood to the amniotic fluid.
*Omphalocele*
- In an omphalocele, the abdominal organs are covered by a **peritoneal sac**, which would not result in viscera "freely suspended" in the amniotic cavity.
- Omphaloceles are often associated with **chromosomal abnormalities** and other congenital anomalies, which are not suggested here.
*Vesicourachal diverticulum*
- This is a rare anomaly of the **urachus**, an embryonic remnant connecting the bladder to the umbilicus.
- It involves a diverticulum of the bladder and would **not cause exposed abdominal organs** or elevated MSAFP.
*Umbilical hernia*
- An umbilical hernia involves a protrusion of abdominal contents through the umbilical ring but is typically **covered by skin** and does not involve free exposure of viscera.
- It usually presents as a **reducible bulge** and is not associated with elevated MSAFP in utero.
*Diaphragmatic hernia*
- This involves a defect in the diaphragm leading to abdominal organs migrating into the **thoracic cavity**, affecting lung development.
- While it can cause some elevation of MSAFP, the ultrasound finding of **viscera freely suspended in the amniotic cavity** is not consistent with a diaphragmatic hernia.
Congenital abdominal wall defects US Medical PG Question 6: A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?
- A. "Does the diarrhea typically precede the constipation, or vice-versa?"
- B. "Is the diarrhea foul-smelling?"
- C. "Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life"
- D. "Are the symptoms worse in the morning or at night?"
- E. "Can you tell me more about the symptoms you have been experiencing?" (Correct Answer)
Congenital abdominal wall defects Explanation: ***Can you tell me more about the symptoms you have been experiencing?***
- This **open-ended question** encourages the patient to provide a **comprehensive narrative** of their symptoms, including details about onset, frequency, duration, alleviating/aggravating factors, and associated symptoms, which is crucial for diagnosis.
- In a patient presenting with vague, intermittent symptoms like alternating constipation and diarrhea, allowing them to elaborate freely can reveal important clues that might not be captured by more targeted questions.
*Does the diarrhea typically precede the constipation, or vice-versa?*
- While knowing the sequence of symptoms can be helpful in understanding the **pattern of bowel dysfunction**, it is a very specific question that might overlook other important aspects of the patient's experience.
- It prematurely narrows the focus without first obtaining a broad understanding of the patient's overall symptomatic picture.
*Is the diarrhea foul-smelling?*
- Foul-smelling diarrhea can indicate **malabsorption** or **bacterial overgrowth**, which are important to consider in some gastrointestinal conditions.
- However, this is a **specific symptom inquiry** that should follow a more general exploration of the patient's symptoms, as it may not be relevant if other crucial details are missed.
*Please rate your abdominal pain on a scale of 1-10, with 10 being the worst pain of your life*
- Quantifying pain intensity is useful for assessing the **severity of discomfort** and monitoring changes over time.
- However, for a patient with intermittent rather than acute, severe pain, understanding the **character, location, and triggers** of the pain is often more diagnostically valuable than just a numerical rating initially.
*Are the symptoms worse in the morning or at night?*
- Diurnal variation can be relevant in certain conditions, such as inflammatory bowel diseases where nocturnal symptoms might be more concerning, or functional disorders whose symptoms might be stress-related.
- This is another **specific question** that should come after gathering a more complete initial picture of the patient's symptoms to ensure no key information is overlooked.
Congenital abdominal wall defects US Medical PG Question 7: A 6-year-old baby is brought to the hospital by her parents complaining about right upper quadrant pain. On examination the baby is found to have jaundice and palpable abdominal mass. USG of the baby is shown below. What is the most likely cause?
- A. Pseudo pancreatic cyst
- B. Hydatid cyst
- C. Choledochal cyst (Correct Answer)
- D. Amoebic liver abscess
- E. Biliary atresia
Congenital abdominal wall defects Explanation: ***Choledochal cyst***
- The classic triad of **abdominal pain**, **jaundice**, and a **palpable right upper quadrant mass** in a child is highly suggestive of a choledochal cyst.
- The ultrasound image shows a **cystic dilatation of the common bile duct** (labeled X), which is the hallmark of a choledochal cyst.
*Pseudo pancreatic cyst*
- Pancreatic pseudocysts usually develop after **pancreatitis** or pancreatic trauma, and are typically located in the **epigastric region**.
- They are not directly associated with jaundice related to biliary obstruction, though large cysts can cause obstruction via compression.
*Hydatid cyst*
- Hydatid cysts are typically seen in the **liver** and are caused by *Echinococcus granulosus*, often presenting with a **multiloculated appearance** and daughter cysts.
- While they can cause hepatomegaly and pain, jaundice and a palpable mass, they do not typically manifest as a primary dilatation of the bile duct.
*Amoebic liver abscess*
- An amoebic liver abscess is caused by *Entamoeba histolytica* and typically presents with **fever**, **right upper quadrant pain**, and sometimes hepatomegaly.
- While it can cause biliary obstruction in rare cases, the ultrasound appearance is usually that of a **hypoechoic lesion** within the liver parenchyma, not a distinct cystic dilatation of the bile duct.
*Biliary atresia*
- Biliary atresia typically presents in **early infancy** (first 2-3 months of life) with progressive jaundice and acholic stools.
- While it causes biliary obstruction, the ultrasound findings show **absent or atretic bile ducts** rather than cystic dilatation, and the age of presentation (6 years) makes this diagnosis unlikely.
Congenital abdominal wall defects US Medical PG Question 8: A 12-year-old patient with esophageal varices is managed by the procedure shown in the image. All of the following statements regarding this condition are true except:
- A. Sengstaken-Blakemore tube
- B. Gastric balloon is inflated with 400 mL of air
- C. Esophageal balloon is inflated with 40 mm Hg pressure of air
- D. This is the definitive treatment (Correct Answer)
- E. Should be kept inflated for a maximum of 24-48 hours
Congenital abdominal wall defects Explanation: ***This is the definitive treatment***
- The image shows a **Sengstaken-Blakemore tube** being used, which is a temporary measure for controlling **bleeding esophageal varices**.
- It is an emergency treatment used for stabilization and does not address the underlying cause of varices or prevent future bleeding.
- **Definitive treatments** include endoscopic variceal ligation (EVL), sclerotherapy, or TIPS procedure.
*Sengstaken-Blakemore tube*
- The device shown in the image, with balloons and multiple lumens, is indeed a **Sengstaken-Blakemore tube**, used for **tamponade of actively bleeding esophageal varices**.
- This tube features a gastric balloon and an esophageal balloon, along with lumens for suction, designed to exert pressure on the bleeding varices.
*Gastric balloon is inflated with 400 mL of air*
- The **gastric balloon** of a Sengstaken-Blakemore tube is typically inflated with **200-500 mL of air** (often around 250-300 ml in adults, 150 ml in children) to anchor the tube and compress gastric varices.
- While 400 mL is within the general range, the exact volume can vary based on patient size and clinical protocol.
*Esophageal balloon is inflated with 40 mm Hg pressure of air*
- The **esophageal balloon** is indeed inflated to a pressure of **20-45 mmHg (typically 30-45 mmHg)** to compress esophageal varices.
- This pressure application is critical for achieving local hemostasis in acute bleeding episodes.
*Should be kept inflated for a maximum of 24-48 hours*
- The balloons should be deflated after **24-48 hours maximum** to prevent complications such as **esophageal necrosis, ulceration, or perforation**.
- Prolonged inflation can cause pressure necrosis of the esophageal or gastric mucosa.
Congenital abdominal wall defects US Medical PG Question 9: What does the intraoperative image shown below depict?
- A. Transverse colon volvulus
- B. Meckel's diverticulum
- C. Intussusception (Correct Answer)
- D. Intestinal duplication cyst
- E. Malrotation with midgut volvulus
Congenital abdominal wall defects Explanation: ***Intussusception***
- The image clearly shows a segment of bowel telescoping into an adjacent segment, characteristic of **intussusception**
- This condition involves the invagination of one part of the intestine into another, often presenting clinically with abdominal pain, vomiting, and **"red jelly" stools**
- The classic intraoperative finding is the appearance of bowel within bowel, creating a sausage-shaped mass
*Transverse colon volvulus*
- **Transverse colon volvulus** involves the twisting of the transverse colon around its mesentery, which would appear as a dilated, twisted loop of bowel
- The image does not show the characteristic twisting or significant dilation associated with a volvulus
*Meckel's diverticulum*
- A **Meckel's diverticulum** is a true diverticulum, a remnant of the vitelline duct, which appears as a small pouch or bulge on the wall of the small intestine
- The image depicts a larger-scale bowel obstruction caused by one segment of bowel entering another, not an abnormal outpouching
*Intestinal duplication cyst*
- **Intestinal duplication cysts** are spherical or tubular structures that share a common wall with the bowel and are lined with gastrointestinal mucosa
- These appear as separate cystic masses adjacent to the bowel, not as telescoping segments
*Malrotation with midgut volvulus*
- **Malrotation with midgut volvulus** presents with twisting of the small bowel around the superior mesenteric artery, creating a characteristic "whirlpool" or "corkscrew" appearance
- The image shows telescoping of bowel segments rather than the rotational twisting pattern seen in volvulus
Congenital abdominal wall defects US Medical PG Question 10: Which of the following is true regarding this condition?
- A. Most common site is anterior triangle neck
- B. It is due to vascular malformation
- C. Usually decreases on crying
- D. Needle aspiration yields fluid that does not coagulate (Correct Answer)
- E. Typically appears after 5 years of age
Congenital abdominal wall defects Explanation: ***Needle aspiration yields fluid that does not coagulate***
- The image depicts a large, translucent, fluid-filled cystic mass, characteristic of a **cystic hygroma** (lymphatic malformation).
- Aspiration of a cystic hygroma typically yields **clear to straw-colored fluid** that is rich in protein but **does not coagulate** because it is lymphatic fluid, not blood.
*Most common site is anterior triangle neck*
- While cystic hygromas most commonly occur in the **neck**, they are typically found in the **posterior triangle**, not the anterior triangle.
- The lesion in the image appears to be a large, diffuse cystic mass extending from the neck into the mediastinum or axilla.
*It is due to vascular malformation*
- This condition is a **lymphatic malformation**, specifically a cystic hygroma, not a vascular malformation.
- **Vascular malformations** involve blood vessels and would typically present with different characteristics, such as being compressible and potentially blanching.
*Usually decreases on crying*
- Crying or straining typically **increases the size** of a cystic hygroma due to increased intrathoracic pressure, which impedes lymphatic flow and causes distention of the lymphatic sacs.
- This characteristic helps differentiate it from conditions that might decrease in size with pressure.
*Typically appears after 5 years of age*
- Cystic hygromas are **congenital malformations** that are usually present at birth or become apparent within the **first 2 years of life** (approximately 90% by age 2).
- Late presentation after 5 years of age is uncommon and would be unusual for this condition.
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