Figure 1. Anteroposterior abdominal radiograph of the patient in the supine position demonstrates a normal bowel-gas pattern including a normal-appearing stomach.
Figure 2. Oblique spot film from an upper gastrointestinal series shows a rounded filling defect in the gastric body.
Figure 3. In a radiograph of the patient in the supine position, the gastric mass has moved dependently into the gastric fundus and appears irregular and partially obscured by barium. These characteristics are typical of a lactobezoar. The pylorus was normal. In the results of fluoroscopy, the barium progressed through the normal small bowel.
Bezoars are defined as "a calculus or concretion found in the stomach or intestine of certain animals."1 Infants and children were believed to acquire bezoars as a result of habitually swallowing hair from dolls, wool from blankets, or proteinaceous material, such as persimmon seeds or various tar products, which form a shellaclike substance after mixing with gastric acids.2 Hairballs (trichobezoars) and vegetable matter concretions (phytobezoars) are more common in developmentally disabled or emotionally disturbed children, who may habitually ingest these indigestible materials.2 Since 1980, reports in the literature3 have suggested the presence of other types of bezoars, such as undigested milk curds (lactobezoars) or bezoars from specific medicines, including antacids.
In infants, lactobezoars are the most commonly encountered type of bezoar. Although the underlying mechanism that causes lactobezoars remains unclear, many studies have shown associated factors that contribute to their formation. The majority of these infants were born preterm (<33 weeks estimated gestational age), had a low birth weight (<1.5 kg), and received formulas containing 3.3 J/mL (24 cal/oz).3- 6 All these formulas had high casein-whey ratios, high calcium-phosphate ratios, and a fat source of medium- and long-chain triglycerides. More recent studies show that lactobezoars occur in full-term infants,7 infants receiving human milk (2.9 J/mL [20 cal/oz]),6,8 and infants receiving soy formula with a low casein-whey ratio.5 Some researchers postulate that physiologic mechanisms, including insufficient gastric secretions or abnormal gastric emptying, cause bezoar formation.9
Patients with a lactobezoar may have abdominal distension, a palpable mass in the left upper quadrant of the abdomen, or nonbilious emesis, which was a symptom of the patient described herein.3 Other patients may not have symptoms, but a masslike foreign body may be seen on a radiograph. Abdominal radiographs may show a normal stomach, bowel, and gas pattern or an intraluminal, mottled gastric mass that is outlined by air. In our patient, the results of an upper gastrointestinal tract examination showed that the mass was intraluminal and separate from the gastric wall. Using abdominal ultrasonography, Naik et al10 showed a hyperechoic intraluminal gastric mass with a heterogeneous echo texture.
Significant morbidity, including gastric obstruction with consequent perforation and metabolic or hemodynamic changes secondary to persistent emesis, has been associated with lactobezoars.5 Appropriate treatment should include early recognition, bowel rest, and formula change to a predigested elemental diet. Medical treatment alone often results in a favorable outcome. Surgery should be reserved for lactobezoars in which complications, such as gastric perforation, have occurred.
Radiological Case of the Month. Arch Pediatr Adolesc Med. 1999;153(5):542. doi: