Introduction: Stomach may be affected by number of malignant pathologies like carcinoma, lymphoma, gastrointestinal stromal tumor (GIST) and metastasis. With non-specific clinical presentation and prognosis depending on histological diagnosis and stage at diagnosis necessitates the need for early imaging diagnosis

Aim: To evaluate the imaging appearance in malignant gastric lesions and deduce narrowest differential diagnosis.

Imaging Findings: Of the various imaging modalities available Barium studies allows good mucosal details, however it provides no extragastric assessment which is necessary for disease staging. Multidetector computed tomography (MDCT) is the most commonly used technique for disease assessment allows disease diagnosis, staging and differentiation between various pathologies. Gastric adenocarcinoma and lymphoma account for majority of malignant lesions. Gastric carcinoma may presents as either polypoidal, ulcerative or as diffusely infiltrating lesion mimicking lymphoma, GIST and metastasis. Gastric lymphomatous involvement is usually secondary   present as bulky non-obstructing gastric thickening with lymphadenopathy extending below renal hila. GIST is the most common mesenchymal tumor may present as submucosal, intramural or extraluminal mass. Imaging features are exophytic mass with variable enhancement, may show cystic change, hemorrhage or fistulous communication with gut. Metastasis to stomach may be either by direct extension or hematogenous dissemination.

Conclusions: Similar pattern of gastric involvement in seen multitude of malignant etiologies, hence careful evaluation of gastric and ancillary findings is necessary to reach definitive diagnosis.

Keywords: Gastric Carcinoma, Lymphoma, Gastrointestinal stromal tumor(GIST), Metastasis, Multidetector computed tomography.

1. Karimi P, Islami F, Anandasabapathy S, Freedman ND, Kamangar F. Gastric Cancer: Descriptive Epidemiology, Risk Factors, Screening, and Prevention. Cancer Epidemiol Biomarkers Prev. 2014; 23: 700–713.
2. Lavelle MI, Venables CW, Douglas AP, Thompson MH, Owen JP, Hacking PM.A Comparative study of double and single contrast Brium meals with endoscopic arbitration in the diagnosis of peptic ulcer. Clin Radiol 1977;28: 625-27.
3. Rubesin SE, Levine MS, Laufer I. Double-Contrast Upper Gastrointestinal Radiography: A Pattern Approach for Diseases of the Stomach. Radiology 2008; 246 :33-48.
4. Ssalamah AB, Prokop M, Pokieser P,Teleky B,Lechner G .Dedicated Multidetector CT of the stomach: Spectrum of disease.2003;23:625-44.
5. Hallinan JT, Venkatesh SK, Gastric carcinoma: imaging diagnosis, staging and assessment of treatment response Cancer Imaging 2013; 13: 212-227.
6. Chen CY, Hsu JS, Wu DC, Kang WY, Hsieh JS, Jaw TS et al. Gastric cancer: preoperative local staging with 3D multi-detector row CT correlation with surgical and histopathologic results. Radiology 2007; 242: 472-482.
7. Wakelin SJ, Deans C, Crofts TJ, Allan PL, Plevris JN, Paterson- Brown S. A comparison of computerised tomography, laparoscopic ultrasound and endoscopic ultrasound in the preoperative staging of oesophago-gastric carcinoma. Eur J Radiol 2002; 41:161-167.
8. Sohn KM, Lee JM,Lee SY, Ahn BY,Park SM, Kim KM. Comparing MR imaging and CT in the staging of Gastric carcinoma.AJR 2000;174:1551-57.
9. Lim JS, Yun MJ, Kim MJ, Hyung WJ, Park MS, Cho JY et al. CT and PET in Stomach Cancer: Preoperative Staging and Monitoring of Response to Therapy. RadioGraphics 2006; 26:143-156 .
10. Stahl A, Ott K, Weber WA, et al. FDG PET imaging of locally advanced gastric carcinomas: correlation with endoscopic and histopathological findings. Eur J Nucl Med Mol Imaging 2003;30:288–295.
11. Yoshioka T, Yamaguchi K, Kubota K, et al. Evaluation of 18F-FDG PET in patients with advanced, metastatic, or recurrent gastric cancer.J Nucl Med 2003;44:690–699.
12. Jemal A, Center MM, DeSantis C, Ward EM. Global patterns of cancer incidence and mortality rates and trends. Cancer Epidemiol Biomarkers Prev. 2010; 19:1893–907
13. Forman D, Burley VJ. Gastric cancer: global pattern of the disease and an overview of environmental risk factors. Best Pract Res Clin Gastroenterol. 2006; 20:633–49.
14. Devesa SS, Blot WJ, Fraumeni JF Jr. Changing patterns in the incidence of esophageal and gastric carcinoma in the United States. Cancer. 1998; 83:2049–53.
15. Powell J, McConkey C. Increasing incidence of adenocarcinoma of the gastric cardia and adjacent sites. Br J Cancer. 1990; 62:440–443.
16. Cavaleiro-Pinto M, Peleteiro B, Lunet N, Barros H. Helicobacter pylori infection and gastric cardia cancer: systematic review and meta-analysis. Cancer Causes Control. 2011; 22:375–87.
17. Kim JH, Eun HW, Goo DE, Shim CS, Auh YH. Imaging of various gastric lesions with 2D MPR and CT gastrography performed with multidetector CT. Radiographics 2006; 26:1101- 16.
18. Edge SB, Compton CC. The American Joint Committee on Cancer: the 7th edition of the AJCC cancer staging manual and the future of TNM. Ann Surg Oncol 2010; 17: 1471-4
19. Kwee RM, Kwee TC. Imaging in local staging of gastric cancer: a systematic review. J Clin Oncol 2007; 25: 2107 -2116.
20. Gore RM. Gastric cancer: clinical and pathologic features. Radiol Clin North Am 1997;35:295–310.
21. Kim JP. Surgical results in gastric cancer. Semin Surg Oncol 1999;17:132–8.
22. Gordon R, Laufer I, Kressel HY. Gastric polyps found on routine double-contrast examination of the stomach. Radiology 1980;134:27–30.
23. Tan CH, Peungjesada S, Charnsangavej C, Bhosale P. Gastric Cancer: Patterns of Disease Spread via the Perigastric Ligaments Shown by CT AJR 2010; 195:398–404.
24. Yu T, Wang X, Zhao Z, Liu F, Liu X, Zhao Yet al. Prediction of T stage in gastric carcinoma by enhanced CT and oral contrast enhanced ultrasonography. World J Surg Onc 2005;184
25. Kim YN, Choi D, Kim SH, Kim MJ, Lee SJ ,Lee WJ et al. Gastric cancer staging at isotropic MDCT including coronal and saggital MPR images: endoscopically diagnosed early vs advanced gastric cancer. Abdom Imaging 2009;34:26-34.
26. Kim HJ,Kim AY,Oh ST, Kim JS, Kim KW, Kim PN et al. Gastric cancer staging at multidetector row CT gastrography: Comparison of transverse and volumetric CT scanning. Radiology 2005;236:879-885.
27. Kwee RM, Kwee TC.Imaging in assessing lymph node status in gastric cancer. Gastric Cancer 2009;12:6-12.
28. Choi J,Joo I,Lee JM. State of the art preoperative staging of gastric cancer by MDCT and magnetic resonance imaging. World J Gastroenterol 2014;20:4546-4557.
29. Pan Z, Zhang H, Yan C,Du L ,Ding B, Song Q et al. Determining gastric cancer respectability by dynamic MDCT.Eur Radiol2010;20:613-620.
30. Kim SJ, Kim HH, Kim YH, Hwang SH, Lee HS, Park DJ et al.Peritoneal metastasis: detection with 16-or 64-detector row CT in patients undergoing surgery for gastric cancer. Radiology 2009;253:407-15.
31. Ghai S, Pattison J, Ghai S, O’Malley ME, Khalili K, Stephens M .Primary Gastrointestinal Lymphoma: Spectrum of Imaging Findings with Pathologic Correlation RadioGraphics 2007; 27:1371–1388 .
32. Dawson IM, Cornes JS, Morson BC.Primary malignant tumors of the intestinal tract.Br J Surg 1961;49:80-89.
33. Smith, R. A. Kubicka, and C. R.Thomas Jr., “Non-Hodgkin lymphoma of the gastrointestinal tract,” RadioGraphics, 1992 ; 12: 887–899, 1992.
34. Herrmann R,Panahon AM,Barcos MP, Walsh D, Stutzman L. Gastrointestinal involvement in non-hodgkin’s lymphoma. Cancer 1980;46:215-222.
35. Engels EA.Infectious agents as causes of non-hodgkin lymphoma. Cancer Epidemiol Biomarkers Prev 2007;16:401-404.
36. Muller AM,Ihorst G, Mertelsmann R, Engelhardt M. Epidemiology of non-Hodgkin’s lymphoma(NHL):trends, geographic distribution and etiology.Ann Hematol 2005;84:1-12.
37. An SK, Han JK, Kim YH, et al. Gastric mucosa associated lymphoid tissue lymphoma: spectrum of findings at double-contrast gastrointestinal examination with pathologic correlation. Radio Graphics 2001;21:1491–1504.
38. Lewis RB, Mehrotra AK, Rodr´ıguez P, Manning MA, Levine MS, “From the radiologic pathology archives: gastrointestinal lymphoma: radiologic and pathologic findings,” RadioGraphics, 2014; 34:1934–1953.
39. Ghimire, G.-Y. Wu, and L. Zhu, “Primary gastrointestinal lymphoma,” World Journal of Gastroenterology, 2011; 17:697–707.
40. Ciftci AO, Tanyel FC, Kotiloglu E, Hicsonmez A. Gastric lymphoma causing gastric outlet obstruction. J Pediatr Surg 1996;31:1424-26.
41. Miller FH, Kochman ML,Talamonti MS,Ghahremani GG, Gore RM. Gastric cancer : radiologic staging.RadiolClin North Am 1997;35:331-349.
42. Cho KC, Baker SR, Altemann DD, Fuscoo JM, Cho S. Transpyloric spread of gastric tumors: comparison of adenocarcinoma and lymphomas.AJR Am J Roentgenol 1996;167:467–469.
43. Buy JN, Moss AA. Computed tomography of gastric lymphoma. Am J Roentgenol 1982;138:859-65.
44. Demetri GD, Benjamin R, Blanke CD .NCCN task force report:Optimal management of patients with gastrointestinal stromal tumor (gist)-expansion and update of NCCN Clinical practice guidelines.J natl Comp Cancer Netw 2004;2:S1-S26.
45. Nishida T, Clark HB.Gastric stromal tumors: reappraisal of histogenesis. Am J Surg Pathol 1983;7:507-519.
46. Burkill GJ, Badran M, Al-Muderis O, Meirion Thomas J, Judson IR, Fisher C, et al. Malignant gastrointestinal stromal tumor: Distribution, imaging features, and pattern of metastatic spread. 2003;226:527–32.
47. Miettinen M, Lasota J. Gastrointestinal stromal tumors: Definition, clinical, histological, immunohistochemical, and molecular genetic features and differential diagnosis. Virchows Arch. 2001;438:1–12.
48. Ludwig DJ, Traverso LW. Gut stromal tumors and their clinical behavior. Am J Surg. 1997;173:390–4.
49. Sripathi S, Rajagopal KV, Srivastava RK, Ayachit A. CT features, mimics and atypical presentations of gastrointestinal stromal tumor (GIST) Indian J Radiol Imaging 2011;21:176-81.
50. Miettinen M, Monihan JM, Sarlomo-Rikala M, Kovatich AJ, Carr NJ, Emory TS, et al. Gastrointestinal stromal tumors/smooth muscle tumors (GISTs) primary to the omentum and mesentery. Am J Surg Pathol 1999;23:1109–18. 
51. King M. The radiology of gastrointestinal stromal tumours (GIST)Cancer Imaging. 2005;5:150–6.
52. Tateishi U,Hasegawa T,Satake M, Moriyama N. Gastrointestinal stromal tumor .Correlation of computed tomography findings with tumor grade and mortality.J Comput Assist Tomogr.2003;27:792-8.
53. Suster S. Gastrointestinal stromal tumors. Semin Diagn Pathol 1996;13:297–313. Miettinen M, Lasota J. Gastrointestinal stromal tumors: Review on morphology, molecular pathology, prognosis, and differential diagnosis. Arch Pathol Lab Med 2006;130:1466-78.

54. Fong Y, Coit DG, Woodruff JM, Brennan MF. Lymph node Miettinen M, Lasota J. Gastrointestinal stromal tumors: Review on morphology, molecular pathology, prognosis, and differentialdiagnosis. Arch Pathol Lab Med 2006;130:1466-78.
55. Ulusan S, Koc Z, Kayaselcuk F. Gastrointestinal stromal tumours: CT findings. Br J Radiol 2008;81:618-23.
56. Haaga JR, Dogra VS, Forsting M, Gilkeson RC, Ha HK, Sundaram M. CT and MRI of the whole body.5^th Ohio.Elsevier 2009.
57. Choi H, Charnsangavej C,Faria SC,Macapinlac HA,Burgess MA,Patel SR.Correlation of computed tomography and positron emission tomography in patients with metastatic gastrointestinal stromal tumor treated aat a single institution with imatinib mesylate : Proposal of New Computed tomography Response Criteria.J  Clin Oncol 2007;25:1753-59.
58. Chen LL,Trent JC,Wu EF Fuller GN,Ramdas L,Zhang W et al.A missense mutation in KITkinase domain 1 correlates with imatinib resistance in gastrointestinal stromal tumors.Cancer Res 2004;64:5913-9.
59. Carney JA. Gastric stromal sarcoma, pulmonary chondroma,and extra-adrenal paraganglioma (Carney triad): Natural history, adrenocortical component and possible familial occurrence. Mayo Clin Proc 1999;74:543-52.
60. Kim SY, Kim KW, Kim AY, Ha HK, Kim JS,Park SH et al. Bloodborne metastatic tumors to the gastrointestinal tract: CT findings with clinicopathologic Correlation.AJR 2006;186:1618-26.

Dr Renu Yadav  MD, DNB, EDiR

Department of Radiodiagnosis, VMMC & SJH, New Delhi