Bezoar is a mass lesion formed by accumulation of indigestible material in the gastric lumen. It is classified as phytobezoar (vegetable fibers — most common type), trichobezoar (hair — Rapunzel syndrome), pharmacobezoar (medication tablets), and lactobezoar (milk proteins — neonates). It generally develops in the setting of gastric motility disorders, prior gastric surgery (especially partial gastrectomy, vagotomy-pyloroplasty), diabetic gastroparesis, or psychiatric disorders (trichotillomania). On CT, it appears as a mottled, heterogeneous, air-containing intraluminal mass within the gastric lumen, and the lack of contrast enhancement is the most critical feature distinguishing it from solid tumors. Large bezoars can cause obstruction, ulceration, and rarely perforation.
Age Range
20-75
Peak Age
50
Gender
Female predominant
Prevalence
Uncommon
Bezoar formation occurs through accumulation of indigestible material in the gastric lumen that compacts over time into an organized mass. In phytobezoar, vegetable fibers (especially dates, persimmon — high tannin content polymerizes with gastric acid creating an insoluble network) harden with mucus and food debris; this polymerization process is reflected on CT as heterogeneous density and trapped air bubbles. In trichobezoar, swallowed hair becomes trapped between gastric rugae and indigestible keratin accumulates; the hydrophobic nature of keratin retains fat and mucus, forming a foul-smelling, black-green mass over time. In 'Rapunzel syndrome,' the hair mass can extend to the duodenum and even jejunum, and linear intraluminal hypodense structures may be seen in the small bowel on CT. Gastric stasis (post-vagotomy pyloric denervation, diabetic gastroparesis, scleroderma) is the most important predisposing factor; normal gastric peristalsis prevents bezoar formation. The mottled appearance on CT reflects air bubbles trapped within the porous bezoar material — unlike solid tumors, this demonstrates the porosity of bezoar material and is a pathognomonic finding in differential diagnosis. Contrast agent is not retained by bezoar material as it contains no vascular structures; therefore, no enhancement is observed in any phase.
On CT, a heterogeneous density intraluminal mass mixed with air bubbles showing no contrast enhancement within the gastric lumen — pathognomonic finding for bezoar. The mass conforms to the gastric lumen shape and is separated from the gastric wall by a thin air line (crescent sign).
On non-contrast CT, a heterogeneous density, air bubble-containing, mottled intraluminal mass is seen within the gastric lumen. The mass conforms to the shape of the gastric lumen and can be assessed as separate from the gastric wall. Phytobezoars are generally of low density and dense calcification is rare; trichobezoars appear more heterogeneous due to hair density. A thin air line (crescent sign) between the bezoar periphery and gastric wall may be seen, confirming intraluminal location.
Report Sentence
An intraluminal mass measuring [X] cm with heterogeneous density containing air bubbles (mottled pattern) is noted within the gastric lumen, consistent with bezoar.
In the arterial phase, the bezoar mass shows no enhancement. While the gastric wall maintains normal enhancement, the intraluminal bezoar remains at the same density as on non-contrast CT. This avascular characteristic is the definitive distinguishing finding from solid tumors (GIST, adenocarcinoma). If oral contrast has been administered, 'meniscus sign' — contrast filling the space between the bezoar and gastric wall — may be seen.
Report Sentence
No enhancement is observed in the intraluminal mass in the arterial phase; this avascular feature supports the diagnosis of bezoar.
In the portal venous phase, gastric wall assessment is critical for detecting bezoar complications. If normal gastric wall thickness (<5 mm) is maintained, the bezoar is considered uncomplicated. Focal wall thickening, mucosal edema, or submucosal stratification indicates pressure ulceration. Asymmetric thickening and mucosal defect in the gastric wall beneath the bezoar are seen in the pre-perforation period. Perigastric free fluid or air suggests perforation complication.
Report Sentence
The gastric wall thickness adjacent to the bezoar is assessed as [normal/increased at X mm], [no complication findings are seen / focal thickening consistent with pressure ulceration is present].
Migration of trichobezoar (especially Rapunzel syndrome) or phytobezoar fragments after fragmentation to the small bowel should be assessed. Small intraluminal, low-density, air-containing masses (bezoar fragments) may be seen in small bowel loops. Small bowel bezoar can cause obstruction; proximal dilatation (>3 cm jejunum, >4 cm ileum) and transition point should be identified. In trichobezoar, a linear hypodense 'tail' structure showing continuity from the gastric mass toward the duodenum and jejunum is the pathognomonic CT finding of Rapunzel syndrome.
Report Sentence
In addition to the gastric bezoar, intraluminal bezoar fragments are seen in the small bowel loops at [location], [with/without signs of obstruction].
On ultrasound, bezoar appears as an intraluminal structure with a hyperechoic surface and prominent posterior acoustic shadowing within the gastric lumen. It is described as 'tumbleweed sign' or 'hyperechoic arc with clean posterior shadowing.' The bezoar surface is irregular and the shadow behind it may also be a 'dirty shadow' — caused by trapped air bubbles producing reverberation artifact. Unlike gallstones, it does not move or moves minimally (as it conforms to the gastric lumen). The gastric wall should be assessed for normal thickness around the bezoar.
Report Sentence
An intraluminal structure measuring [X] cm with hyperechoic surface and posterior acoustic shadowing is seen within the gastric lumen, consistent with bezoar.
On MRI, bezoar shows heterogeneous signal intensity on T2-weighted sequences. Organic material generally exhibits intermediate-low T2 signal, while trapped air bubbles cause susceptibility artifact creating areas of signal loss. Fluid component (mucus, gastric fluid) shows high T2 signal. On T1-weighted sequences, bezoar is generally of low-intermediate signal intensity. On post-contrast series, no enhancement is seen — confirming avascular nature consistent with CT findings.
Report Sentence
On MRI, a heterogeneous T2 signal intensity intraluminal mass with susceptibility artifacts and no enhancement is seen in the gastric lumen, consistent with bezoar.
In the delayed phase, the bezoar mass continues to show no enhancement — enhancement is absent in all phases. This is an important distinguishing feature from some benign lesions with delayed enhancement (fibroma, desmoid) and late-enhancing malignant tumors. In cases with oral contrast, penetration of contrast between bezoar material may be assessed in the delayed phase; however, no enhancement with IV contrast is definitively observed. In complicated cases, inflammatory changes in the gastric wall may become more apparent in the delayed phase.
Report Sentence
No enhancement is observed in the intraluminal mass in the delayed phase, confirming avascular structure (bezoar).
Criteria
Composed of vegetable fibers, most common bezoar type (40-55%). Generally develops in elderly, edentulous patients with gastroparesis or prior gastric surgery history. Fiber-rich foods like persimmon, dates, pineapple, celery are most common causes.
Distinct Features
On CT, intermediate-low density, granular structure, prominent air bubbles. Usually treated with enzyme therapy (Coca-Cola, cellulase) or endoscopic fragmentation. Calcification rare.
Criteria
Bezoar composed of hair, generally seen in young women with trichotillomania + trichophagia (hair eating). Rapunzel syndrome: hair tail extending from gastric mass to small bowel. Requires psychiatric evaluation.
Distinct Features
On CT, more heterogeneous and dense structure (keratin density). Can completely fill the gastric lumen ('gastric cast'). Surgical removal usually required — endoscopic fragmentation difficult. On MRI, very low signal on T1 and T2 (keratin).
Criteria
Bezoar formed by accumulation of medication tablets. Especially antacids (aluminum hydroxide), iron preparations, sucralfate, bismuth, kaolin and sustained-release preparations responsible. Can also form after drug overdose.
Distinct Features
On CT, tablet shapes may be discernible, can show high density (especially iron, bismuth tablets — metallic density). High-density foci resembling calcification characteristic of pharmacobezoar. Treatment includes gastric lavage or endoscopic removal.
Criteria
Bezoar composed of milk proteins (casein), seen in neonates and infants. Prematurity, high-calorie formula formulations, and dehydration are predisposing factors. Generally presents with abdominal distension and feeding intolerance.
Distinct Features
On abdominal radiograph, gastric distension and intraluminal opaque material. On US, irregular echogenic mass in the stomach. CT rarely needed (radiation concerns). Conservative treatment (feeding cessation, gastric lavage) usually sufficient.
Distinguishing Feature
Adenocarcinoma originates from the gastric wall and shows enhancement; bezoar is intraluminal, avascular, and non-enhancing. Adenocarcinoma causes wall thickening and luminal narrowing while bezoar forms a free mass within the lumen.
Distinguishing Feature
GIST is a submucosal mass with intense arterial enhancement; bezoar is intraluminal and non-enhancing. GIST connects to the gastric wall (bridging vessel), bezoar is separate from the gastric wall (crescent sign).
Distinguishing Feature
Lipoma is a submucosal mass with homogeneous fat density (-70 to -120 HU); bezoar is heterogeneous density containing air. Lipoma is submucosal in location and non-enhancing but its density is homogeneous and characteristically low.
Distinguishing Feature
Leiomyoma is a well-defined, homogeneous, moderately enhancing submucosal mass; bezoar is intraluminal, non-enhancing, and contains air bubbles. Leiomyoma shows continuity with the gastric wall, bezoar is free within the lumen.
Distinguishing Feature
Polyp is mucosal in origin with contrast-enhancing pedicle or broad-based structure; bezoar is a free intraluminal mass that does not enhance and is not attached to the gastric wall.
Urgency
routineManagement
conservativeBiopsy
Not NeededFollow-up
specialist-referralBezoar treatment depends on type and size. For phytobezoar, Coca-Cola lavage (acidic pH dissolves tannin polymerization), enzyme therapy (cellulase, papain), or endoscopic fragmentation is first-line. Trichobezoar usually requires surgery (laparotomy or laparoscopy) — endoscopic fragmentation is difficult due to tight keratin structure. Gastric lavage is applied for pharmacobezoar. Complicated cases (obstruction, perforation, bleeding) require emergency surgical intervention. Treatment of the underlying cause (gastroparesis management, psychiatric evaluation) is essential in long-term management. Recurrence rate is high (14-20%) if the underlying cause is not treated.
Bezoars can cause obstruction, ulceration, and rarely perforation. Phytobezoars can be dissolved with enzymatic (Coca-Cola) or endoscopic treatment. Trichobezoars usually require surgery. Underlying psychological condition should be evaluated.