Clinical History

A child’s age, gender, and thorough clinical history help to identify the most likely disease category ( Tables 17.1 and 17.2 ). The duration and character of associated symptoms are important for narrowing the differential diagnosis (e.g., fatigue, fever, appetite changes, vomiting, stooling history, weight loss, night sweating, character and frequency of pain, hematuria, flushing, palpitations, lower extremity swelling, lymph nodal prominence, and jaundice). A history of abdominal trauma should be elicited, as solid organ injuries may result in hematoma, seroma, persistent pseudocyst, or arteriovenous malformation. Infectious disease may have sequelae of cyst, lymphadenopathy, or intraabdominal abscess. Some systemic diseases (e.g., glycogen storage, hereditary spherocytosis), genetic syndromes (e.g., Beckwith-Wiedemann, Peutz-Jeghers, familial adenomatous polyposis), and anomalies (aniridia with Wilms tumor, isolated hemihypertrophy with neuroblastoma and Wilms tumor) are associated with intraabdominal tumors. A family and sexual history are also pertinent, particularly in adolescent females. Modern prenatal imaging frequently identifies congenital malformations and neoplasms, requiring postnatal imaging and surgical assessment.

Physical Examination

A complete physical exam should be performed in children with abdominal masses. Attention should be paid to the general condition of the child and to signs of metastatic disease. Enlarged lymph nodes and their locations should be noted, the skin inspected, and the lungs and heart auscultated. Extremities should be evaluated for evidence of swelling, venous phlegmasia, or evidence of embolic disease. Genitourinary exam should make note of any inappropriate virilization, testicular changes, and hymenal patency in the case of a female with a low pelvic mass. In addition, a neurologic examination may reveal signs of nervous system involvement. The eyes should be carefully inspected for periorbital ecchymosis, proptosis, squint, opsoclonus-myoclonus syndrome, heterochromia of the iris, Horner syndrome, and scleral icterus. The patient’s blood pressure must be determined and may be elevated in patients with Wilms tumor, neuroblastoma, or pheochromocytoma.

To successfully perform abdominal palpation in a child, the physician must approach the patient calmly and gently, as the most reliable exams are completed in cooperative and relaxed children. Enlarged organs may be missed in a struggling child who does not lie quietly. When cooperation proves difficult in an infant, the examining hand should be placed and remain static on the abdomen and the exam completed between cries or as the child calms in the parent’s arms. Creative play is sometimes necessary, with the use of pacifiers or bottles to distract the child from the exam. Re-examination after voiding or defecating elucidates contributions of constipation and urinary retention in the child’s presentation.

The abdominal quadrants should be examined systematically ( Table 17.3 ; Figs. 17.1 and 17.2 ). With the patient in the supine position, the symmetry of the abdomen should be inspected, and any visible masses or the presence of ascites should be noted. A very enlarged spleen is frequently visible, with fullness of the left side of the abdomen. The presence of tense fluid-filled hernias or prominent periumbilical veins as sequelae of portal hypertension should be noted. The mass should be localized, and its size, shape, texture, mobility, tenderness, and relation to midline noted. The umbilical position is a useful marker of abdominal asymmetry.

Signs of peritoneal inflammation must be sought (see Chapter 10 ). Dull visceral pain conducted by slow C nerve fibers may be reported for inflammatory processes in the vascular distributions of the celiac, superior mesenteric, and inferior mesenteric arteries and referred to the epigastrium, umbilical region, or hypogastrium, respectively. When the inflamed process contacts the peritoneum, peritoneal fast A nerve fibers allow discrete localization of sharp pain to the abdominal wall. Ultrasound is often a very useful adjunct in the evaluation of an abdominal mass and is often available at the bedside.

Approximately half of abdominal masses in older children are caused by enlargement of the liver or spleen, or both. The liver is normally palpated in the right upper quadrant and epigastrium extending 1-2 cm below the costal margin. The inferior hepatic margin may be palpated in a thin child, is usually nontender, and moves with respiration. Detection of liver edge by auscultation using skin scratches has been proven unreliable and has been supplanted by the use of readily available ultrasound. The spleen is located in the left upper quadrant and is nonpalpable in most healthy children. To locate an enlarged spleen, the examiner must begin palpation in the patient’s right iliac fossa (to avoid missing a grossly enlarged spleen or liver with extension of the left hepatic lobe into the splenic area in the left upper quadrant); the examiner’s right hand should move toward the patient’s left upper quadrant to find the spleen’s lower pole or medial border. The examiner’s left hand is placed in the patient’s left flank, and gentle displacement of the thoracic cage toward the examiner’s right hand often displaces the spleen forward enough to make it appreciable. The spleen has a rounded tip and should move downward with inspiration and is more superficial than a renal mass. It is equally important for the examiner to palpate the spleen as it is for the spleen to “touch” the examiner during its descent with inspiration. Overaggressive palpation may push the spleen away, whereas gentle or light palpation permits the examiner to feel the spleen’s edge passively. The characteristic notch in the medial or inferior border may not be palpable when the spleen is enlarged only a few centimeters, but the notch’s presence usually clearly distinguishes an enlarged spleen from other abdominal masses on the examination alone. Because the extent to which the spleen extends below the costal margin depends heavily on the patient’s position, the extent of the spleen below the costal margin should be measured with the patient in the supine position. Measurement from the left costal margin to the lower pole of the spleen defines the splenic axis. Ordinarily, the long axis of the spleen is along the length of the 10th rib. As it enlarges, it extends medially and downward. Masses in the left upper quadrant, especially left renal masses, may be difficult to distinguish from an enlarged spleen. In general, the presence of the splenic notch helps identify the mass as a spleen, but nodular masses, such as Wilms tumors of the kidney, neuroblastomas, and retroperitoneal teratomas may masquerade as splenomegaly. Many enlarged spleens are not palpable on physical examination because of their relationship to other organs and the thoracic cage. Hyperinflation of lungs (as occurs in asthma, bronchiolitis, ipsilateral pneumothorax) may make a normal-sized liver or spleen palpable.

Flank masses are the next most frequent, particularly in newborn to toddler-aged children. Renal masses extend caudally, are fixed with respiration, and cause abdominal asymmetry. Lower abdominal masses are most commonly caused by constipation or urinary retention. These may be functional or secondary to neurogenic dysfunction. A perforated appendix with resulting abscess formation may create a tender right lower quadrant mass. Ovarian or uterine tumors often grow undetected in the pelvis until large enough to exit the pelvis as a large palpable abdominal mass.

Laboratory and Imaging Studies

Screening laboratory data, including complete blood count with differential and cell morphology, measurements of serum electrolytes, urinalysis, urine pregnancy test when appropriate, and inflammatory markers, are broadly applicable. Liver function tests, serum amylase, tumor marker levels ( Table 17.4 ), and renal function tests are often important initial objective data points.

Plain abdominal radiographs may reveal tumor calcifications, organomegaly, excess fecal load, and mass effect upon intestines. Views in at least 2 different positions should be obtained to appreciate ascites or intestinal obstruction. As a screening modality, ultrasonography is a highly efficient, low-cost, and widely available test. It is noninvasive, nonirradiating, and can give detailed information on the location, vascularity, and nature of the mass and adjacent structures ( Fig. 17.3 ). The most widely used axial imaging technique is computed tomography (CT) ( Fig. 17.4 ), followed by magnetic resonance imaging (MRI). These modalities often provide radiologic diagnosis, are invaluable for surgical planning, and are unhampered by bowel gas, a common limitation of ultrasound. MRI pulse sequences have evolved to discriminate between primary malignant, metastatic, and hamartomatous liver lesions.

An ultrasonic longitudinal view of the pelvis reveals hydrometrocolpos. The uterus and cervix are readily seen superior to the large collection of fluid in the vagina located at the right of the image.

Computed tomogram revealing a large Wilms tumor replacing the right kidney. Notice that the renal cortex, enhanced by contrast medium, is splayed out around the mass. This characteristic helps differentiate Wilms tumor from neuroblastoma, which would displace a normal-appearing kidney.