Index of Suspicion

Abstract

A 12-year-old girl has had abdominal pain for 3 hours. The pain developed suddenly and is severe, sharp, constant, and located in the epigastrium and lower quadrants, with no radiation. She has had five episodes of bilious, nonbloody emesis. The pain worsens with movement and vomiting, and she has found no way to relieve it. Her last bowel movement was yesterday and was normal. She has had no fever, diarrhea, bloody stools, or back pain. Past medical history reveals intermittent constipation.On physical examination, her temperature is 96.3°F (35.7°C), heart rate is 106 beats/min, respiratory rate is 14 breaths/min, and blood pressure is 103/60 mm Hg. Her abdomen is soft and slightly distended, with hypoactive bowel sounds and both right and left lower quadrant tenderness. Slight voluntary guarding is noted. The rest of the physical findings are normal.Her WBC is 9.6×103/mcL (9.6×109/L), Hgb is 11.4 g/dL (114 g/L), Hct is 33.3% (0.333), and platelet count is 406×103/mcL (406×109/L). Values for electrolytes, BUN, creatinine, liver enzymes, amylase, and lipase are within normal limits; a pregnancy test is negative.Abdominal/pelvic CT scan with intravenous contrast reveals a moderate amount of free fluid around the cecum; the appendix is not visible. Pelvic and abdominal ultrasonography is read as normal, but the appendix is not visible.Following intravenous hydration, she experiences persistent bilious vomiting and abdominal pain and undergoes a diagnostic laparoscopy, which is converted to an exploratory laparotomy when no colon is located on the right side of her abdomen. The cause of her pain and vomiting is revealed at surgery.A 14-year-old girl is seen in the ED because of 2 days of lower abdominal and back pain. The pain is a constant, dull, bandlike ache of 9/10 in intensity. She denies fever, nausea, vomiting, diarrhea, melena, hematochezia, dysuria, hematuria, vaginal discharge, or constitutional symptoms. She is premenarchal and denies sexual activity.She had an appendectomy at age 5 years complicated by the development of necrotic bowel, requiring a small bowel resection. After recovering from surgery, she developed chronic intermittent abdominal pain, ultimately diagnosed as being functional. She describes her current pain as different from her chronic abdominal pain.On physical examination, the girl is uncomfortable but in no apparent distress and looks healthy. All vital signs are normal. Her breast development is at Sexual Maturity Rating 5. She is thin and easy to examine. Her back is straight, with no tenderness to palpation over the spine, paraspinal muscles, or costovertebral angles. Her abdominal examination reveals a 10-cm linear, well-healed vertical scar down the midline and a slightly protuberant lower abdomen. Palpation reveals a large, well-defined, firm mass extending from the pelvis halfway to the umbilicus in the mid-line. Mild pain is elicited on deep palpation of the left lower quadrant, with no guarding or rebound tenderness. Additional examination reveals the diagnosis.A 6-month-old boy is readmitted because of respiratory distress and hypoxia 1 day after a 2-week hospitalization for bronchiolitis with hypoxia. Despite resolution of signs of a respiratory tract infection, he was difficult to wean from supplemental oxygen, having percutaneous oxygen saturations of 88% to 92% in room air. He was discharged after his percutaneous oxygen saturations remained at 90% to 96% for 24 hours in room air. He was a small-for-gestational age neonate, born via caesarean section at 36 weeks’ gestation for maternal double uterus, and remained in the neonatal intensive care unit for 2 weeks for feeding and weight gain. He did not receive any mechanical ventilation, and his growth and development have been normal.On physical examination, the patient's weight is in the 10th percentile, height is in the 5th percentile, and head circumference is below the 3rd percentile. His blood pressure, heart rate, and respiratory rate are normal. Percutaneous oxygen saturations in room air are 91%. He is receiving 2 L of supplemental oxygen by nasal cannula and has no respiratory distress. Wheezing is audible bilaterally, and there is no heart murmur. He has a left facial nerve palsy present since birth. Adequate perfusion and palpable pulses are noted in all extremities. The remaining physical findings are normal.A chest radiograph reveals multifocal atelectasis, a left-sided aortic arch, and a cardiac silhouette that measures at the upper limit of normal. Additional evaluation reveals the diagnosis.At laparotomy, intestinal malrotation with small bowel obstruction at the level of the distal ileum was found.Intestinal malrotation is an anatomic anomaly caused by arrest of normal rotation and mesenteric fixation of the embryonic gut, a failure of normal embryologic gut formation that occurs between the 5th and 10th weeks of gestation. The result of a nonrotated gut is location of the colon on the left side and a narrow-based mesentery in the upper mid-abdomen that is fixed to the right abdominal wall by adhesions known as Ladd bands. Anomalies commonly associated with intestinal malrotation include duodenal atresia (50%) and jejunal atresia (33%). Disorders of intestinal rotation and mesenteric fixation to the posterior abdominal cavity are also common in infants and children who have congenital diaphragmatic hernia, gastroschisis, and omphalocele.Intestinal malrotation is believed to occur in 1 per 200 to 1 per 500 live births, with symptomatic malrotation occurring in 1 per 6,000 live births. Symptomatic malrotation is evident clinically in the first postnatal month in 64% of patients, and 82% are diagnosed in the first postnatal year; 18% to 25% of symptomatic patients are diagnosed at 1 year of age and older. Because malrotation is discovered incidentally in some patients, the true number of patients who have malrotation that is never detected can only be estimated.Malrotation can cause duodenal obstruction because of impingement on the bowel by the Ladd bands. The most serious consequence is a midgut volvulus, a life-threatening condition in which the intestine twists on the mesenteric stalk and compromises its blood supply, which can lead rapidly to infarction of the entire small bowel. Both duodenal obstruction from Ladd bands and volvulus may occur intermittently, characterized by chronic and sometimes vague complaints of abdominal pain with or without vomiting.Symptomatic malrotation with volvulus presents as duodenal obstruction. In infancy, the clinical picture includes bilious emesis, abdominal pain, diffuse tenderness, and bloody stool. Some clinicians warn that the cause of bilious vomiting in a neonate should be considered mechanical intestinal obstruction until proven otherwise. Older children and adults can present with acute or chronic symptoms. Acute symptoms include bilious vomiting, diffuse abdominal pain, and bloody stool.Among the chronic symptoms are intermittent vomiting and abdominal pain, constipation, malabsorption syndrome, chronic diarrhea due to protein-losing enteropathy, and failure to thrive. Older children and adults who have chronic symptoms may have received a previous diagnosis of irritable bowel syndrome or cyclic vomiting. Some individuals who are diagnosed later in childhood are believed to have been experiencing intermittent, self-resolving volvulus.The differential diagnosis for intestinal malrotation varies according to the age of presentation. In infancy and childhood, conditions to consider include necrotizing enterocolitis, pyloric stenosis, intussusception, ileus due to sepsis or meconium, Hirschsprung disease, appendicitis, and duodenal atresia. In older children and adults, similar symptoms can result from inflammatory bowel syndrome, pancreatitis, or acute abdominal conditions such as appendicitis.Diagnostic evaluation generally requires a degree of suspicion for volvulus and, in a stable patient, can include abdominal radiography, upper GI radiographic series, or abdominal CT scan. Adjunctive imaging techniques are abdominal ultrasonography and barium enema. Radiographs often reveal a gasless colon with a “double-bubble” sign due to duodenal obstruction. An abdominal radiograph was not performed in this patient because appendicitis was believed to be likely, and abdominal radiography would not have been an optimal study for appendicitis.An upper GI contrast study usually is considered the imaging study of choice in a stable patient suspected of having intestinal malrotation complicated by volvulus. An upper GI radiographic series reveals failure of the duodenal-jejunal junction to cross the midline and a corkscrew appearance of volvulus at the level of the duodenum. CT scan may reveal duodenal obstruction (in the case of mid-gut volvulus) or appear normal in the absence of volvulus. Ultrasonographic findings suggestive of volvulus include identification of the superior mesenteric vein on the left rather than the right.Intestinal malrotation requires surgical intervention. The Ladd procedure is recommended for intestinal malrotation regardless of age or symptoms. This operation includes lysis of adhesions, widening of the mesenteric base, and positioning of the bowel in a place of nonrotation as well as appendectomy and resection of any necrotic bowel. The urgency of the operation is dictated by the presence of intestinal ischemia caused by volvulus. In the setting of malrotation without volvulus, most surgeons advocate the Ladd procedure as a prophylactic maneuver to reduce the probability of volvulus.This patient underwent a Ladd procedure, and Doppler ultrasonography at the time of surgery showed normal blood flow to the distal ileum. Postoperatively, she developed pancreatitis, which resolved after approximately 1 week of bowel rest and fluid resuscitation. She was discharged with no additional complications.Most symptomatic cases of malrotation occur during infancy and usually present with bilious vomiting. Fewer cases present after infancy and have varied presentations related to intermittent volvulus, with symptoms that include abdominal pain, vomiting, and diarrhea. Volvulus can mimic an acute abdominal inflammatory process, and diagnosis requires a high degree of suspicion because progressive intestinal ischemia may become life-threatening. Patients who present after infancy usually have a history of chronic abdominal complaints. (Cherilyn Hall, MD, Allen Friedland, MD, Sumathi Sundar, MD, Christiana Care Health System, Newark, Del.)Examination of the patient's genitalia revealed a normal vulva and labia with Sexual Maturity Rating 5 distribution of pubic hair. A bulging, bluish membrane that was firm to palpation protruded from the introitus (FigureF1).Abdominal and pelvic ultrasonography performed to confirm the diagnosis of imperforate hymen revealed a grossly dilated vagina filled with homogeneous, echogenic material consistent with hematocolpos. No other urogenital abnormalities were present. The patient was admitted for a hymenectomy and evacuation of retained clotted blood. After an uncomplicated hymenectomy, the patient was discharged in good condition with relief of pain.Imperforate hymen is the most common obstructive genital tract anomaly occurring in females, having an incidence of 1 in 1,000 to 1 in 10,000 individuals. Most commonly, imperforate hymen is detected during adolescence either during an evaluation for asymptomatic primary amenorrhea or an investigation of abdominal, back, or pelvic pain in the premenarchal female. Other complaints include urinary retention and pain with defecation. The pain is due to the collection of menstrual blood in the vagina and uterus. An imperforate hymen also can be detected on prenatal ultrasonography as hydrocolpos if it is associated with urinary obstruction and a urogenital fistula, during a newborn examination as a mucocolpos from maternal estrogen-induced secretions, or during a health supervision visit as a membrane that bulges when the child performs a Valsalva maneuver. The term hydrometrocolpos is used when both vagina and uterus are dilated with fluid.Imperforate hymen is a sporadic congenital outflow obstruction anomaly resulting from the failure of canalization of the tissue joining the müllerian ducts and the urogenital sinus during development. Embryologically, the female genital tract involves the medial migration and midline (horizontal) fusion of the paired müllerian (paramesonephric) ducts to form the uterus, cervix, and upper vagina and the vertical fusion of the developing ductal system with the invaginating urogenital sinus to form the lower vagina and introitus. Horizontal fusion defects result in vaginal agenesis (also known as müllerian agenesis or Mayer-Rokitansky-Kuster-Hauser syndrome) and may have associated urinary system abnormalities. Failure of vertical fusion results in low obstruction abnormalities, such as imperforate hymen, transverse vaginal septum, and cervical atresia, which usually are not associated with urinary abnormalities. All of the previously noted conditions result in an accumulation of menstrual fluid above the level of obstruction.The ovarian structures are derived from a separate embryologic source, the genital ridge. Therefore, ovarian hormonal and endocrinologic function is normal in patients who have genital outflow tract abnormalities, which causes an apparent discrepancy between physical findings of advanced secondary sexual characteristics and lack of menses.An imperforate hymen is diagnosed by genital examination, which reveals a translucent thin membrane inferior to the urethral meatus that bulges when the patient performs the Valsalva maneuver. If hematocolpos is present, a bluish discoloration is apparent behind the membrane. The volume of blood that collects can be great enough to fill and distend the uterus (hematometra), which may present as an abdominal or pelvic mass. Prolonged menses in a girl who has an imperforate hymen may lead to hematosalpinges and retrograde menses into the abdomen, which may cause intra-abdominal endometriosis and adhesions.Although an imperforate hymen should be obvious on physical examination, several conditions may present with similar complaints and findings. A history of primary amenorrhea in the presence of a blind or absent vagina indicates a variety of developmental anomalies of the genital outflow tract, including imperforate hymen, low-lying transverse vaginal septum, cervical atresia, vaginal (müllerian) agenesis, and androgen insensitivity syndrome (AIH). Of these conditions, imperforate hymen, transverse septum, and cervical atresia commonly present at the expected time of menarche in a girl who has well-developed secondary sexual characteristics and the complaint of cyclical lower abdominal, back, or pelvic pain. On examination, imperforate hymen appears typically as a thin, bulging blue membrane; transverse septa and cervical atresia can be associated with a normal vaginal opening but shortened vaginal canal. Ultrasonography can help evaluate the level and volume of sequestered menses; MRI provides superior anatomic detail to define the nature of anomalies further, including those of the upper urinary tract. Only in rare instances is laparoscopy required to clarify an anatomic developmental anomaly.Vaginal (müllerian) agenesis and AIH usually are asymptomatic presentations of primary amenorrhea associated with a vaginal anomaly. Patients born with vaginal agenesis experience variable uterine development, with only 2% to 7% having a uterus that has a functioning endometrium. This group may present with cyclic or chronic abdominopelvic pain due to hematometra, but this clinical picture is the exception.Extragenital anomalies are common in vaginal agenesis and should be screened for, particularly urologic (30%) and skeletal (15%) abnormalities. AIH differs from the other mentioned anomalies in that it is a genetic disorder of a chromosomal male (XY) but phenotypic female due to an androgen receptor mutation causing androgen insensitivity in the tissues and resulting in a blind vagina, absent uterus, and testes in the inguinal canal. Imaging, along with evaluation of karyotype and hormone concentrations, further delineates this disorder.Hymenectomy is the definitive treatment for an imperforate hymen. Abdominal ultrasonography is recommended before surgery to demonstrate that the true diagnosis is not an obstructing transverse septum or other genital anomaly. If abnormalities are present, the condition may be more complex than a simple imperforate hymen, and surgery should be delayed until the appropriate evaluation is performed, including MRI of the abdomen and pelvis.Surgical treatment of an imperforate hymen is not an emergency procedure. If a preadolescent is found to have an imperforate hymen on examination but otherwise is asymptomatic, surgery often is delayed until puberty to allow the hymen to become estrogenized, optimizing the surgical outcome. A more urgent hymenectomy is needed if the patient also has urinary obstruction.In addition to hymenectomy, treatment for an imperforate hymen consists of evacuating copious amounts of retained blood products and suturing the vaginal epithelium to the hymeneal ring. The outcome of imperforate hymen treated with hymenectomy is excellent. Follow-up in patients who have had imperforate hymen treated has shown normal pregnancy rates and sexual function. Gynecologists have observed that if endometriosis develops from retrograde menses, it is more likely to resolve and have no significant effect on fertility compared with spontaneous endometriosis occurring in the general population.A teenage girl who has lower abdominal pain and back pain may bring to mind an extensive differential diagnosis, leading to extensive laboratory and radiologic testing. However, the history and physical examination remain the most useful tools at the physician's disposal to make the diagnosis. In this case, the patient's advanced breast development and lack of menses did not correlate and, in the presence of recurring abdominal and back pain, led to the suspicion of imperforate hymen. Imperforate hymen is the most common cause of vaginal outflow obstruction, and surgical repair can relieve the obstruction and ensure commencement of normal menses. (Kathryn S. Torok, MD, Mananda S. Bhende, MD, Children's Hospital of Pittsburgh, Pittsburgh, Pa.)The baby continued to require supplemental oxygen and demonstrated respiratory distress with feedings. A video swallow study showed no evidence of aspiration. CT scan of the chest performed to evaluate pulmonary anatomic abnormalities as a cause for prolonged hypoxia revealed a vascular structure to the left of the aorta consistent with a duplicated superior vena cava or anomalous pulmonary venous connection. An ECG showed right atrial enlargement and findings consistent with right ventricular hypertrophy. Echocardiography confirmed the diagnosis of unobstructed supracardiac total anomalous pulmonary venous connection (TAPVC), with the pulmonary veins draining into the innominate vein. A large secundum atrial septal defect (ASD) with right-to-left shunting also was present.TAPVC is a cyanotic heart defect that represents approximately 1% to 3% of all congenital heart defects. Males are affected more often than females (4:1). Some 33% of affected patients have additional cardiac malformations, and 33% have other noncardiac malformations.TAPVC results from a developmental error that prevents a direct communication of the pulmonary veins to the left atrium. The pulmonary veins drain into the systemic venous system or directly into the right atrium. In this malformation, an obligatory right-to-left shunt nearly always occurs at the atrial level. Formerly called total anomalous pulmonary venous return, the condition more appropriately is called TAPVC. The abnormality is the connection, not the return, because the veins can empty circuitously into the left atrium or blood can flow into the left atrium through an ASD.The four types of TAPVC are based on the location of the pulmonary vein connection: supracardiac (50%, commonly into the left innominate vein or right superior vena cava), cardiac (20%, commonly into the coronary sinus), infracardiac/subdiaphragmatic (20%, commonly into the portal vein, ductus venosus, hepatic vein, or inferior vena cava), and mixed (10%).The presence of an obstructed pulmonary venous connection affects the clinical presentation. Typically, tachypnea and cyanosis occur within the first few days after birth as pulmonary blood flow increases. The obstructed flow causes pulmonary edema and decreased lung compliance, which manifests as increased work of breathing and hypoxia. Feeding difficulties and other signs of heart failure often are present. In addition, there is a fixed and widely split second heart sound due to a delay in pulmonary valve closure caused by right ventricular volume overload. Some infants also develop pulmonary hypertension because of the obstruction.Without obstruction, there may be no symptoms at birth. However, symptoms usually appear within the first postnatal year. Signs may include dyspnea on exertion and visible cyanosis with crying. Examination usually reveals a pulmonary murmur caused by increased flow across the valve. The murmur may be difficult to hear if there is pulmonary vein obstruction. It can be distinguished from pulmonic valve stenosis by the absence of a pulmonary valve click. An ASD causes a similar pulmonary flow murmur and fixed splitting of the second heart sound.Rhonchi may be present in some patients. As with this child, percutaneous oxygen saturations may be decreased only slightly because initial pulmonary blood flow remains high and a large interatrial connection allows oxygenated blood to flow into the left atrium and systemic circulation. Progressive cyanosis results from increasing pulmonary edema that impairs oxygenation and decreasing right heart compliance that increases the interatrial right-to-left shunt. Both obstructed and unobstructed types can cause congestive heart failure, growth restriction, and multiple pulmonary infections.Chest radiography may show an enlarged heart with increased pulmonary flow, a “snowman” shape (in supracardiac TAPVC), or an enlarged upper right heart border. ECG shows right atrial and right ventricular enlargement. The diagnosis is confirmed by identifying a pulmonary venous connection to the systemic veins, coronary sinus, or right atrium on echocardiography.Most patients who have TAPVC do not survive beyond the first year without surgery. Emergent surgery may be necessary for neonates who are in cardiogenic shock due to TAPVC. Infants afflicted with infracardiac TAPVC die before 2 months after birth without surgery. Advancements in surgical correction have lowered mortality rates to near zero and increased long-term survival to 98% at 7 years.Many nurseries routinely check percutaneous oxygen saturations at birth. This screening is nearly 100% specific in detection of cyanotic heart defects. (1) Without screening and a high level of suspicion, a subset of patients born with congenital heart disease will be missed. Patients who manifest cyanotic heart disease outside of the neonatal period may present with growth restriction or failure to thrive, a history of recurrent respiratory infections, mild or episodic cyanosis, or irritability.As with this patient, persistent hypoxemia despite resolution of an infectious respiratory process is a major sign of cyanotic heart disease. Indeed, many patients who have cyanotic congenital heart defects are asymptomatic at birth because of the presence of intracardiac mixing of oxygenated and deoxygenated blood that increases the arterial oxygen saturation. Infants born with hypoplastic left heart syndrome or left heart obstruction or who experience increasing pulmonary blood flow as the pulmonary vascular resistance falls naturally (single ventricle without pulmonary stenosis, large ventricular septal defect) eventually show signs and symptoms of heart failure or pulmonary edema. Unfortunately, for those who have left heart obstruction, symptoms of heart failure may be subtle and the phase of decompensation rapid.Signs and symptoms of congestive heart failure include irritability, poor feeding, failure to thrive, tachypnea without respiratory distress (“happy tachypnea”) or tachypnea with respiratory distress due to pulmonary edema or pleural effusion, and hepatomegaly. Any patient suspected of having a cyanotic heart defect or congestive heart failure should be screened with a chest radiograph and ECG. Echocardiography provides the definitive diagnosis.Recognizing signs and symptoms of cyanotic heart defects and early symptoms of congestive heart failure is critical to the early recognition, management, and surgical correction of these lesions. (Grace Pecson, MD, Carolyn Leedy, MD, University of Texas Southwestern Medical Center, Children's Medical Center, Dallas, Tex.)