Neoplastic stomach lesions and their mimickers: spectrum of imaging manifestations

Abstract

This review illustrates a wide spectrum of gastric neoplasms with emphasis on imaging findings helpful in characterizing various gastric neoplasms. Both the malignant and benign neoplasms along with focal gastric masses mimicking tumour are illustrated. Moreover, imaging clues to reach an accurate diagnosis are emphasized.

Figure 1

A 58-year-old man with gastric carcinoma. Oblique coronal contrast-enhanced CT reveals diffuse thickening (arrows) and enhancement of the gastric wall in the distal stomach with obliteration of the gastric folds and decreased distension in the affected region. This is classic Linitis plastica and on pathology was a T3 signet-ring cell carcinoma. This subtype of gastric carcinomas frequently involves the distal half of the stomach, is often understaged and has a higher rate of peritoneal spread.

Figure 2

Contrast CT demonstrates a large polypoidal mass (arrows) along the lesser curvature of the stomach with a smooth outer gastric wall and the absence of perigastric stranding signifying T2 gastric carcinoma.

Figure 3

Coronal contrast CT shows focal markedly enhancing wall thickening in the antrum (circle) with resultant gastric outlet obstruction. There is an irregular border with a blurred fat plane along the medial margin (arrow) signifying T3 carcinoma.

Figure 4

Surgically proven infiltrative mucinous gastric carcinoma in a 45-year-old man. Coronal contrast CT reveals diffuse low attenuation thickening of the gastric wall with punctuate calcifications (arrows). The thin high-attenuating inner layer (arrowhead) is preserved while the middle and outer layers show low density thickening; this along with the punctate calcifications favours mucinous adenocarcinoma. Inset: image at the level of the pelvis reveals bilateral complex solid cystic masses (arrows) consistent with ovarian metastases or Krukenberg tumours. Mucinous gastric carcinoma is a rare subtype of gastric carcinoma and has a poorer prognosis than other subtypes.

Figure 5

Low-grade gastric lymphoma in a 45-year-old man presenting with loss of appetite and dyspepsia. Axial CT demonstrates segmental circumferential, poorly enhancing homogeneous thickening of the distal body of the stomach (arrowheads). The perigastric fat planes are maintained and there is no gastric outlet obstruction. There were no enlarged lymph nodes. Biopsy revealed MALT lymphoma, a relatively indolent form of lymphoma with a good prognosis.

Figure 6

A 45-year-old man with large B-cell gastric lymphoma and peritoneal lymphomatosis. Axial contrast-enhanced CT shows diffuse concentric, homogeneous thickening of the gastric wall (arrowheads) measuring 4–5 cm with maintained perigastric fat planes. Inset: image at the level of the lower pole of the kidneys reveals diffuse infiltration of the omentum (white arrows) and extensive mesenteric (arrowheads) and retroperitoneal lymphadenopathy (black arrows). The presence of lymph nodes below the renal hilum, as in this case, would be unusual in metastatic lymphadenopathy from gastric carcinoma and favours lymphoma.

Figure 7

Diffuse large B-cell gastric lymphoma infiltrating the spleen. (a) Axial contrast-enhanced CT reveals bulky a heterogeneous mass (arrows) infiltrating the spleen (arrowheads). (b) Follow-up coronal contrast-enhanced CT after four cycles of chemotherapy shows localized perforation of the stomach (arrows) with extensive adjacent infiltration by the mass. The patient was referred for surgery and underwent splenectomy and partial gastrectomy, which demonstrated gastric perforation and fistulization with the spleen.

Figure 8

Malignant gastric GIST in a 54-year-old man presenting with gastrointestinal bleeding and epigastric pain. Axial enhanced MRI demonstrates a large, well-defined mass with a predominant exogastric component (white arrow) arising from the greater curvature. There is an avidly enhancing peripheral component with central non-enhancing necrosis. Inset: image reveals the mass to be intermediate to high signal intensity (arrow) on T2-weighted MRI.

Figure 9

A 62-year-old man with malignant GIST. Coronal contrast-enhanced CT reveals a large, lobulated, heterogeneous mass with extensive contiguous peritoneal spread (arrowheads). It is compressing the stomach (arrow).

Figure 10

Surgically proven gastro-gastric intussusception with malignant gastric GIST as the lead point. Axial contrast-enhanced CT reveals opacified blood vessels and mesenteric fat (white arrow) within intussusceptum (black arrow), which represents the lesser curvature of the stomach. The thin outline of the intussuscipiens is barely perceived (arrowheads). Inset: caudal axial section reveals a homogeneously enhancing mass as the lead point (arrowheads). Pathology revealed it to be a malignant GIST. True gastro-gastric intussusception is extremely rare and has been reported in polyps or in a gastric remnant through gastrojejunal anastomosis.

Figure 11

Type III gastric carcinoid in a 39-year-old man with carcinoid syndrome. (a) Axial contrast-enhanced CT shows a solitary homogeneous exogastric mass (arrow) arising from the lesser curvature with multiple calcific foci within it (arrowhead). (b) Axial T1-weighted and (c) T2-weighted MRI shows the mass (arrow) to be hypointense on the T1-weighted image and mildly hyperintense on the T2-weighted image. (d) Contrast-enhanced arterial phase MRI reveals the mass (arrow) is intensely hypervascular.

Figure 12

Metastases to the stomach in a 45-year-old man with a history of treated superficial spreading melanoma of the back. Contrast-enhanced CT reveals multiple smooth submucosal masses (arrows) with hypodense centre (arrowhead) mimicking the bull’s eye appearance. Metastases were confirmed on histopathology.

Figure 13

A 58-year-old woman with gastric linitis plastica from metastatic lobular carcinoma of the breast. Contrast-enhanced CT shows a diffusely thickened and enhancing gastric wall (arrows). There were also multiple lung and hepatic metastases (not shown).

Figure 14

Kaposi sarcoma of the stomach in a 32-year-old HIV-positive man. Axial CT with oral contrast reveals multifocal variable sized submucosal nodules (arrows) in the stomach. Inset: image reveals well-defined nodules (arrows) in the antropyloric region and proximal duodenum. The skin and gastrointestinal tract are the most common organs involved in Kaposi sarcoma and within the gastrointestinal tract, the stomach and small bowel are most commonly affected.

Figure 15

Gastric neurogenic tumour in a 29-year-old man with epigastric pain. Inset: axial non-contrast CT shows a predominantly exophytic submucosal mass (arrow) arising from the fundus of the stomach with a speck of calcification within it (arrowhead). Axial contrast-enhanced CT at the same level demonstrates mild homogeneous enhancement within the mass (arrow). A large exogastric component and calcification are not typical features of gastric neural tumours. Enhancement is variable but usually less than that seen in GIST.

Figure 16

Gastric lipoma incidentally detected in a 36-year-old woman. Axial non-contrast CT demonstrates a well-defined submucosal endogastric fat density mass (arrow) in the fundus of the stomach. There is minimal adjacent gastric wall thickening (arrowhead).

Figure 17

Gastric and small bowel hamartomatous polyps in a 16-year-old boy with Peutz-Jeghers syndrome. Axial contrast-enhanced CT reveals multiple clustered, sessile, homogeneously enhancing polyps in the body of the stomach (arrowheads). Inset: caudal sections of the pelvis reveal small bowel intussusception (arrow) with a polyp as the lead point (arrowhead).

Figure 18

Adenomatous gastric polyps in a 28-year-old man with familial polyposis coli. Axial contrast-enhanced CT reveals innumerable sessile and pedunculated polyps (arrows) measuring 1–4 cm distributed diffusely in the stomach. Biopsy confirmed that many of these harboured malignant foci.

Figure 19

Myofibroblastic tumour in a 14-year-old girl with epigastric pain. Axial non-contrast CT shows a well-defined, hypodense mass (arrow) arising from the body of the stomach with a predominant exogastric component. A speck of calcification is seen at the periphery of the mass (arrowhead). Inset: contrast-enhanced CT demonstrates peripheral enhancement of the lesion (arrowheads). Intraoperatively the lesion was arising from the gastric serosa. Pathology revealed it to be a myofibroblastic tumour.

Figure 20

Ectopic pancreatic rest in a 35-year-old man presenting with gastrointestinal bleeding. Coronal T2-weighted MRI demonstrates a well-defined submucosal lesion along the prepyloric greater curvature of the stomach (arrow). The lesion parallels the signal intensity of the pancreas on the T2-weighted image. A few small cystic areas within the lesion were confirmed to be an anomalous dilated duct on pathology. Inset: coronal T1-weighted MRI reveals the lesion (arrow) to be mildly hyperintense on the T1-weighted image, again following the signal intensity of the pancreas.

Figure 21

Adult hypertrophic pyloric stenosis secondary to scarring of a gastric ulcer in a 54-year-old man presenting with abdominal pain and vomiting for 6 months. (a) Axial contrast CT reveals circumferential smooth wall thickening of the antropyloric region (arrowheads) with narrowing and elongation of the pylorus (arrow). (b) Coronal CT further confirms wall thickening and narrowing of the pylorus and the appearance resembles that of a cervix (cervix sign) (dotted). A preoperative diagnosis of carcinoma was made. The patient underwent distal gastrectomy and pathology, which showed it to be benign wall thickening from hypertrophic pyloric stenosis.

Figure 22

A 65-year-old patient with AIDS with intramural gastric and liver abscess. Axial contrast-enhanced CT revealed heterogeneously enhancing masses in the wall of the stomach (black arrow) and liver (white arrow). Biopsy revealed abscess in both the liver and stomach with gram-negative organisms.

Figure 23

Gastric duplication cyst in a 21-year-old woman presenting with epigastric pain. Contrast-enhanced CT revealed a cystic lesion (black arrow) along the medial wall of the fundus with an air speck (white arrow) within it suggesting communication with the stomach. There is no significant enhancement. Pathology confirmed gastric mucosa within the cystic lesion.