Abdominal Masses

Clinical History

A child’s age, gender, and thorough clinical history help to identify the most likely disease category ( Tables 20.1 and 20.2 ). 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, von Hippel-Lindau, familial adenomatous polyposis, hereditary pheochromocytoma, PTEN hamartoma tumor), and anomalies (aniridia with Wilms tumor, isolated hemihypertrophy with neuroblastoma and Wilms tumor, Hirschsprung with neuroblastoma) are associated with intraabdominal tumors. A family history is pertinent as is a menstrual and sexual history, particularly in adolescent females. 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 (fever, pallor, petechiae, cachexia) 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 to bone, muscle, or skin. 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 central or peripheral 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 clinician 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 20.3 ; see Figs. 20.1 and 20.2 ). 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 13 ). 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. Hepatomegaly is discussed in detail in Chapter 17 . 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 left 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. 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, a splenic notch, if present, 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 the lungs (as occurs in asthma, bronchiolitis, and 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 CBC 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 20.4 ), 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 two 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, is nonirradiating, and can give detailed information on the location, vascularity, and nature of the mass and adjacent structures ( Fig. 20.3 ). The most widely used defining imaging technique is CT ( Fig. 20.4 ), followed by MRI. These modalities often provide radiologic diagnosis, are invaluable for surgical planning, and are unhampered by bowel gas, a common limitation of ultrasound. MRI or CT when combined with functional PET scanning can define primary, metastatic, and recurrent disease ( Figs. 20.5 and 20.6 ).

History

Birth and medical history, including transplacentally acquired infections, especially congenital syphilis, are often associated with splenic enlargement. History of a neonatal umbilical venous catheter, perhaps accompanied by occult portal venous injury or thrombosis, may progressively obstruct the extrahepatic portal vein, leading to congestive splenomegaly. Recurrent infections suggest immunodeficiency. Liver disease may lead to portal hypertension, which may in turn lead to splenomegaly. Congestive heart failure and associated congenital cardiac malformations have an increased risk of abdominal heterotaxia with splenic malformation and splenomegaly. Abdominal trauma may acutely produce a splenic hematoma ( Fig. 20.7 ) or may be followed by development of a chronic splenic pseudocyst.

A family history of anemia, transfusions, early biliary stones, cholecystectomy, and splenectomy may indicate hemolytic anemia. Identification of Mediterranean (thalassemia, glucose-6-phosphate dehydrogenase [G6PD] deficiency), African (sickle cell disease, G6PD deficiency), southern Asian (thalassemia, G6PD deficiency), or Ashkenazi Jewish (storage disease) ancestry in patients with splenomegaly is helpful in identifying an inherited process.

Social and behavioral issues of parents, children, and adolescents heavily affect certain risks and exposures. Sexual encounters and intravenous and illicit drug exposure may expose patients to hepatitis, cytomegalovirus, and HIV. Sexual abuse may place even young children at risk; it may be difficult to elicit an accurate history.

A review of systems in a patient with splenomegaly should elucidate related conditions. Systemic symptoms, such as fever or weight loss, are seen in many disorders that manifest splenomegaly, particularly infections, malignancies, and inflammatory or granulomatous processes, such as hemophagocytic lymphohistiocytosis (HLH) and sarcoidosis. When fever is acute in onset, infection is most likely. Chronic fever, often gradual in onset and not associated with chills, is more likely to be caused by inflammatory processes (systemic lupus erythematosus [SLE], juvenile idiopathic arthritis [JIA], sarcoidosis, Langerhans cell histiocytosis) or tumors (lymphomas, especially Hodgkin disease, or leukemia). Exposure to infectious agents or a travel history that might result in exposure to infectious agents unusual for the patient’s community (malaria, leishmaniasis, schistosomiasis, trypanosomiasis for U.S. citizens with a travel history to an endemic country) should be determined. Pallor suggests anemia (hemolysis, bone marrow infiltration, hypersplenism); purpura and petechiae suggest thrombocytopenia (bone marrow failure, autoimmune disorder, hypersplenism, bone marrow infiltration); and jaundice and conjunctival icterus suggest hemolytic anemia, liver dysfunction, or both. Rashes caused by a variety of acute and chronic infections and inflammatory diseases (SLE, JIA, infective endocarditis, HLH) and hemangiomata that are part of a systemic process involving the spleen may provide clues to splenic disease. Dyspnea, cough, orthopnea, and fatigue suggest respiratory disease (Langerhans cell histiocytosis or sarcoidosis), anemia, congestive heart failure, or malignancy (Hodgkin disease). Diarrhea caused by Salmonella infection or inflammatory bowel disease may be accompanied by splenic enlargement. Abdominal pain accompanied by splenomegaly may be attributable to acute splenic capsule distention or caused by coincident gallstones, hepatitis, or trauma. Joint pain resulting from SLE, JIA, and other autoimmune inflammatory diseases may be associated with splenomegaly. Bone pain is a feature of bone marrow infiltrative processes, particularly leukemia or neuroblastoma or storage disease (Gaucher disease). Poor vision in an infant with splenomegaly suggests osteopetrosis (with deafness) or uveitis-iritis (sarcoidosis, JIA). Loss of developmental milestones occurs with storage diseases. Splenomegaly may accompany neurologic paraneoplastic syndromes (such as myasthenia gravis) secondary to lymphoma or lymphoproliferative syndromes.

Physical Examination

Nutritional status and growth parameters provide clues to disorders that affect the patient’s metabolic state and tissue oxygenation. Malnutrition (as evidenced by such problems as weight loss and failure to thrive) in a child with splenomegaly suggests malignancy, chronic hemolysis, immunodeficiency or chronic infection, a metabolic disorder, or liver disease. Pallor, petechiae, purpura, jaundice, hemangiomata, septic emboli to the skin, infiltrative lesions (leukemia cutis, solid tumors), seborrhea, or eczema (as occurs in Langerhans cell histiocytosis and immunodeficiency) should be noted. Cherry-red retinal spots or cloudy corneas suggest storage diseases. Conjunctival pallor, scleral icterus, fundal hemorrhages, evidence of sinus infection or otitis media, condition of gingivae, and evidence of salivary gland enlargement should be noted. The clinician should look for signs of heart failure or new or changing murmurs, which suggest valvular or other structural heart disease or endocarditis. Any respiratory distress, rales, rhonchi, or suggestion of pneumonia or asthma should be noted. Abdominal distention, prominent veins on the abdomen, hepatomegaly, fluid wave, tenderness, or rebound should be noted, as should specific characteristics and size of the spleen itself. A hard or nodular spleen suggests malignancy or chronic hemolysis. A tender spleen suggests either acute enlargement or infection, or both. A spleen that is more than 5 cm below the left costal margin is usually not transient and represents significant disease. Arthritis, splinter hemorrhages, and poor bone growth (as occurs in storage diseases and osteopetrosis) should be noted. Size, texture, mobility, tenderness, and distribution of lymph nodes should be noted. Enlarged (>1 cm), firm, fixed lymph nodes are suggestive of lymphoma or leukemia. Tender enlarged lymph nodes are suggestive of more common infections. Developmental delay suggests chronic infection, immunodeficiency, or storage diseases.

Approach to the Child with Splenomegaly

The most common cause of splenomegaly in childhood is viral infection, which should induce only moderate splenomegaly (<5 cm below the left costal margin) that is transient, lasting <4–6 weeks. Other common causes include autoimmune disorders and destruction of abnormal blood cells (such as brisk hemolysis). The approach to the child with splenomegaly is affected by several key factors, each of which indicates the probability of significant disease necessitating diagnosis and intervention ( Fig. 20.8 A and B ).

Laboratory Investigation

Table 20.6 summarizes key diagnostic laboratory investigations.