Concepción actual de la Marca

is largely dependent on resectability, thus, the primary goal of therapy is resection.

a. Primary resection is the optimal form of therapy. Next is by high-dose doxorubicin and cisplatin.

b. For initially unresectable tumors, preoperative chemotherapy may allow for later resection of an otherwise unresectable tumor.

9. Survival

is related to histology and resectability of the tumor.

a. Pure fetal histology tumors

that are completely excised have a nearly 90% long-term survival rate.

b. Mixed tumors

completely resected, have a long-term survival rate of approximately 60%.

Review Test

Directions: Each of the numbered items or incomplete statements in this section is followed by answers or by completions of the statement. Select the ONE lettered answer or completion that is BEST in each case.

1. A newborn boy is noted to experience a choking episode during the first feeding attempt. The child is noted to have excessive drooling. There is no respiratory distress when the child is not feeding. An orogastric tube does not pass the estimated distance into the stomach, meeting obstruction just past the oropharynx. A chest/abdomen radiograph reveals the orogastric tube to be coiled at the level of the third thoracic vertebra. Lung fields are normal, and the abdomen appears to have a normal distribution of air. Which of the following is the most likely diagnosis?

(A) Acquired esophageal stenosis (B) Esophageal atresia

(C) Esophageal atresia with proximal fistula

(D) Proximal esophageal atresia with distal tracheoesophageal fistula (E) Isolated tracheoesophageal fistula

1-D. Esophageal atresia usually presents with excessive drooling in a child who experiences choking with feedings. The orogastric tube typically coils at the level of atresia. The presence of air in the distal gastrointestinal tract demonstrates a distal tracheoesophageal fistula. In the absence of distal fistula, there is no gas on the abdominal radiograph. Isolated fistula occurs without atresia, but is differentiated by the passage of the orogastric tube. Acquired esophageal stenosis does not frequently present in newborns.

2. A 3-week-old boy is being evaluated for persistent vomiting for the past 4 days. The emesis has been nonbilious and forceful with every feeding. The child is hungry after each episode of emesis. Examination reveals mildly decreased skin turgor, dry mucous

membranes, and a nondistended abdomen. There is a palpable pyloric tumor in the midepigastrium. Which of the following is the most likely diagnosis?

(A) M alrotation with midgut volvulus (B) Duodenal atresia

(C) Annular pancreas (D) Pyloric stenosis (E) Jejunal atresia

2-D. Hypertrophic pyloric stenosis typically occurs at 3 weeks of age and is associated with persistent nonbilious vomiting. Children may become dehydrated as the disease progresses. The palpation of a pyloric tumor is diagnostic of pyloric stenosis. M alrotation, annular pancreas, and jejunal atresia typically present with bilious emesis. Despite the proximal nature of the obstruction, duodenal atresia also typically presents with bilious emesis because the atretic segments are frequently beyond the ampulla of Vater.

3. A 2-week-old child is being evaluated in a local emergency room for green-stained vomiting. The mother reports that the child had been well until today, when he began vomiting and developed abdominal distension. The child is awake and crying inconsolably with a distended abdomen. There are no palpable abdominal masses. Intravenous access is established. A plain abdominal radiograph reveals a nonobstructive gas pattern. Among the possible diagnoses listed, which of the following is the most life-threatening condition in the acute period?

(A) Viral gastroenteritis (B) Lactose intolerance

(C) M alrotation with midgut volvulus (D) Hirschsprung disease

(E) Pyloric stenosis

3-C. The patient's clinical description is the typical presentation of malrotation with midgut volvulus. Viral gastroenteritis may present with emesis but frequently presents with diarrhea as well. The suspicion of pyloric stenosis is based on history and is not likely in the patient presented because these children usually do not have bilious emesis or abdominal distension. Hirschsprung disease is usually suspected on the basis of delayed passage of meconium in the newborn period. Formula- or lactose-intolerance is not usually associated with bilious emesis.

4. A newborn child is noted to have a small umbilical defect to the right of a normal-appearing umbilical cord. The bowel is encased in a matted mass of inflammatory tissue. Which of the following is most consistent with these findings?

(A) Gastroschisis (B) Omphalocele (C) Umbilical hernia (D) Diaphragmatic hernia (E) Prune-belly syndrome

4-A. Gastroschisis is usually a small umbilical defect through which the bowel herniates. There is no covering sac, and the bowel therefore becomes encased in an inflammatory process. Unless ruptured, an omphalocele is generally covered by mesenchyma (Wharton's jelly). An umbilical hernia is covered by skin. A diaphragmatic hernia does not present as an umbilical defect. Prune belly syndrome is a congenital absence of abdominal wall musculature and is not associated with exposed bowel.

5. A 1-day-old child is referred for evaluation of abdominal distension and feeding intolerance. The child has previously passed meconium. On examination, the child is in no distress, the abdomen is mildly distended, and bowel sounds are normal. An abdominal radiograph shows several air fluid levels in the upper abdomen. There is no air in the distal bowel. Which of the following is the most likely diagnosis?

(A) Duodenal atresia (B) Jejunal atresia (C) Hirschsprung disease (D) Imperforate anus

(E) Esophageal atresia with tracheoesophageal fistula

5-B. Jejunal atresia presents in the newborn period with feeding intolerance and abdominal distension related to the level of atresia.

These children are not usually in distress, although massive abdominal distension may lead to respiratory distress. Duodenal atresia is not associated with dilated loops of small bowel or with distal air fluid levels. Hirschsprung disease is associated with delayed passage of meconium and massive abdominal distension. Imperforate anus is diagnosed by the physical finding of absent or abnormally located anus. In esophageal atresia, there is an absence of stomach air.

6. A 2-day-old infant presents in the nursery with persistent bilious emesis since birth. Physical examination reveals a distended abdomen. An upper gastrointestinal series reveals obstruction at the level of the ileum with a stricture approximately 4 cm long. Which of the following is the most likely cause of this anomaly?

(A) Failure of recanalization following a period of mucosal overgrowth (B) Failure of craniocaudal migration of the myenteric plexus of nerves

(C) Intrauterine vascular compromise resulting in involution of the associated segment of bowel (D) Intrauterine midgut volvulus

(E) Failure of the midgut to return to the abdominal cavity following the elongation phase of intestinal development

6-C. This patient's findings are consistent with ileal atresia. Small bowel atresias are the result of an intrauterine vascular event leading to ischemic involution of the associated portion of bowel. The other descriptions given are not causes of primary congenital intestinal atresia.

7. A 1-day-old infant with trisomy 21 develops bilious emesis after the first feeding. Which of the following characteristic findings would most likely suggest the diagnosis of duodenal atresia?

(A) String sign on contrast upper gastrointestinal film (B) Abdominal distension and bilious emesis

(C) Double bubble sign on plain abdominal film (D) Palpable epigastric mass

(E) Persistent jaundice with a right upper quadrant mass

7-C. Duodenal atresia is classically diagnosed by the finding of a double bubble sign on plain abdominal radiograph, usually with little or no distal gas. Upper gastrointestinal film may confirm the double bubble, but string sign is more indicative of pyloric stenosis than duodenal atresia. These children do not have abdominal distension, because the level of obstruction does not permit gas to pass into the distal bowel. A palpable epigastric or right upper quadrant mass is not associated with duodenal atresia.

8. A 1-week-old male infant presents to the emergency room with a 12-hour history of bilious emesis. The parents state that the baby has been crying since the onset of the emesis and that the symptoms developed acutely. Among the choices below, which of the following is the next step in the management of this child?

(A) Resuscitation and stool cultures (B) Contrast upper gastrointestinal series (C) Abdominal ultrasound

(D) Resuscitation and rectal biopsy

(E) Obtain blood sample for serum electrolytes

8-B. All children presenting with bilious emesis should be suspected of having a surgical problem until proven otherwise. The upper gastrointestinal series is the most reliable diagnostic study to rule out malrotation. The diagnostic upper gastrointestinal series in the child suspected of having midgut volvulus should be obtained immediately, because the delayed diagnosis is nearly uniformly fatal.