Systematic review of giant gastric lipomas reported since 1980 and report of two new cases in a review of 117110 esophagogastroduodenoscopies

Table 1 Comprehensive review of the 32 giant gastric lipomas reported since 1980

Ref.	Age, sex, clinical presentation, PMH, signs and lab abnormalities	Diagnostic work-up	Treatment, pathology	Outcome and follow-up
Upper GI bleeding
Current case report 1	63 y. o. M with previous medical history of hypertension and hyperlipidemia presented with melena and dyspnea on exertion for 3 d and epigastric pain, early satiety and 10-kg weight loss during the last 6 mo. BP = 144/77 mm/Hg, pulse = 87/min. Hgb = 6.2 g/dL	EGD: 13-cm-wide, submucosal, yellowish, gastric mass in antrum covered by smooth mucosa except for focal ulcerationAbdominal CT: well-circumscribed, uniform 13.4 cm × 8.4 cm × 8.2 cm mass, with attenuation characteristic for fat	Laparotomy: Resected by subtotal gastrectomy extended by partial bulbar duodenectomy with Billroth II reconstructionPathology: Homogeneous, submucosal, soft, 14.5 cm × 8.7 cm × 7.5 cm mass. Lipoma with spindle cell variant by CD34 positivity by immunohistochemistry	Did well postoperatively with no complications. Asymptomatic at 8 wk of follow-up
Current case report 2	78 y. o. F presented with melena for 3 d, associated with weakness and orthostatic dizziness. BP = 124/67 mmHg, pulse = 68/min. Rectal exam-melena. Hgb = 7.1 g/dL	Abdominal CT: submucosal, 9.5 cm × 6.0 cm × 4.5 cm, antral mass. EGD: large, focally ulcerated, antral gastric mass, exhibiting a positive cushion sign	Laparotomy: large, 9.0 cm × 6.0 cm × 4.5 cm, submucosal mass excised by distal gastrectomy. Pathology: lipoma	Patient discharged 5 d postoperatively with no further bleeding
Ramdass et al[1], 2013	37 y. o. F with epigastric pain, melena, vomiting and weakness for 4 d. Pallor and epigastric tenderness. Hgb = 5.9 g/dL. Transfused 6 units packed erythrocytes	EGD: submucosal mass with 1 cm central ulcer in gastric body	Gastric body. Laparotomy: 4 cm × 3.5 cm × 3.2 cm mass at junction of body and antrum removed surgicallyPathology: lipoma	Did well postoperatively with uneventful recovery
Almohsin et al[2], 2015	61 y. o. M presented with hematemesis, melena, epigastric pain, and fatigue	EGD: Gastric mass with an ulcer. Endoscopic biopsies: benign tissue. EUS: large, hyperechoic, antral, submucosal lesion. Abdominal CT: 8.5 cm × 5 cm submucosal, well-encapsulated antral lesion with density of fat with ulcerated overlying mucosa	Laparotomy: enucleation of lesion and overlying mucosa. Pathology: lipoma	Remained well at 9 mo follow-up
Beck et al[3] ,1997	13 y, o. M with hematemesis, melena and abdominal pain for 2 d. Occasional nausea and vomiting for several years. Benign abdomenHgb = 10.5 g/dL	Abdominal radiograph: polypoid mass. EGD: 8 cm × 3 cm × 4 cm soft and compressible, polypoid mass with basal ulceration on anterolateral wall of antrum. Endoscopic mucosal biopsy: normal antral tissue. Abdominal CT: smooth, uniform intraluminal mass with low attenuation in submucosal layer	Endoscopic polypectomy: Unsuccessful due to thick polyp stalk and patient pain during attempted polypectomySurgery: Excision of polypPathology: lipoma	Uneventful postoperative course. Patient asymptomatic
Bijlani et al[4], 1993	70 y. o. M presented with acute hematemesis. Physical examination revealed pallor. Hgb = 7.0 g/dL	EGD: Protruding mass in antrum. Could not traverse endoscope beyond mass. Endoscopic biopsies: normalUGI series: space-occupying lesion in antrumAbdominal USD: normal	Laparotomy: soft, yellowish mass in antrum stretching the serosa. Mass enucleated via serosal approachPathology: lipoma	Uneventful post-operative recovery. Asymptomatic at 6 mo of follow-up
Bloch et al[5], 1974	55 y, o. F with 1 episode of melenaNausea, epigastric fullness, and belching for 7 mo. Physical exam reveals grapefruit-sized epigastric massN.A	Supine abdominal radiograph: Well-demarcated, large epigastric massUGI series: huge, sharply demarcated, mass in distal two-thirds of stomach with 2 cm × 3 cm ulcer at apex of mass	Distal two-thirds of stomach on anterior wall. Laparotomy: huge, grapefruit size submucosal lipoma arising from anterior wall with shallow central ulcerSurgical resection: not documented	N.A
Chu et al[6], 1983	61 y. o. F with previous medical history of gastric ulcer and hiatal hernia diagnosed 2 yr earlier presented with melena and weakness for several days. Rectal exam: fecal occult blood. Hgb = 6.0 g/dL. Transfused 3 units of packed erythrocytes	UGI series: sliding hiatal hernia, and golf-ball-sized mass protruding from lesser curve in antrum. Mass moved in and out of pylorusEGD: well-circumscribed, submucosal, 5 cm × 3 cm-mass protruding along lesser curve in antrum. Positive cushion sign	Laparotomy: 5 cm × 4 cm × 3 cm mass in pre-pylorus. Underwent resection of mass with adjacent lesser curvature, and pyloroplastyPathology: lipoma	Uneventful postoperative course and asymptomatic at 1 yr
Kibria et al[7], 2009	44 y. o. F with hematemesis and melena for 1 d. Hgb = 8.6 g/dL	EGD: Soft, broad-based, 5 cm × 3 cm mass on greater curvature of stomach. Two ulcers on mass. Positive cushion sign. Abdominal CT: 4.5 cm × 3.0 cm gastric mass with attenuation of fat projecting into lumen. Doppler-assisted EUS: submucosal mass of mixed echogenicity	Greater curvature of stomachSurgical resection, 4.8 cm × 3.2 cm, mature adipocytes with ulceration and necrosis of overlying mucosa	Uneventful recovery. Unremarkable EGD at 6 mo of follow-up
Kumar et al[8], 2015	72 y. o. previously healthy M presented with presyncope associated with diaphoresis and pallor. Rectal exam revealed melena. Hgb = 9.9 g/dL	Abdominal CT: 4.3-cm-wide polypoid mass in antrum consistent with gastric lipoma. EGD: large, submucosal mass in gastric antrum with central ulcer with overlying clot. Ulcer injected with dilute epinephrine	Laparotomy: Gastrostomy with wide excision of antral lesion along anterior wall. Pathology: lipoma	Good postoperative recovery and discharged 3 d after surgery
López Cano et al[9], 1991	76 y. o. M with recent NSAID use, and hypertension presented with acute melena. Hgb = 6.8 g/dL	EGD: posterior wall of antrum 3.5-cm-wide lesion with overlying smooth mucosa. Central ulceration. Endoscopic biopsy: gastritis. Abdominal ultrasound with water-filled stomach: 4-cm-wide, echogenic submucosal mass	Partial gastrectomyPathology: lipoma	No postoperative complications
Myint et al[10], 1996	54 y. o. F presented with hematemesis and melena for 1 wk. BP = 70/50 mmHg. Benign abdominal exam. Hgb = 4.0 g/dL.	EGD: 4 cm × 3 cm ulcerated submucosal mass in antrumEndoscopic biopsies: nondiagnostic. Abdominal CT: gastric mass with attenuation value of lipoma	Laparotomy: 6 cm × 6 cm mass in posterior wall of gastric antrum with central ulceration. Pathology: lipoma	Patient alive with no evident disease 6 mo after surgery
Ortiz de Solórzapo Aurusa et al[11], 1997	60 y. o. F. PMH: vitiligo, acute pancreatitis, duodenal ulcer presented with melena, postprandial pain, nausea, vomiting and early satiety. Pallor. Rectal exam: melena. Hgb = 12.8 g/dL	EGD: antral deformity. No active bleeding. Gastric volvulus? Abdominal USD: 5.8 cm × 3.4 cm pedunculated antral mass intussuscepting into duodenum. Abdominal CT: 4 cm × 3 cm × 3-cm-wide, well-defined, submucosal mass	Surgery; Underwent partial gastrectomy for antral mass intussuscepting into duodenum. Pathology: lipoma	Did well for 6 mo of follow-up
Paksoy et al[12], 2003	71 y. o. M with acute hematemesis and melena. BP = 110/70 mmHg, Pulse = 100/minHematocrit = 27%	EGD: 4 cm-wide mass with superficial ulcer on posterior gastric wall. Endoscopic biopsies: “benign” lesionAbdominal CT: 4 cm lesion of lipid density in inferioposterior wall of stomach	Inferioposterior wall of stomachSurgery: laparoscopic transgastric resection of 4 cm intramural lipomaPathology: intramural lipoma	Discharged 6 d postoperatively without complications
Pérez Cabañas et al[13], 1990	73 y. o. M presented with melena and hematemesis for 2 d. Recent NSAID use. PMH: hypertension. Physical exam: pallor, rectal exam-melena. Hgb = 8.6 g/dL. Transfused 5 units of packed erythrocytes	EGD: gastric mass on posterior wall and greater curve with superficial overlying ulcer, small hiatal hernia. Abdominal ultrasound: normal stomach. UGI series: large filling defect, from submucosal lesion	Surgery: Wedge resection for 5 cm × 4 cm submucosal massPathology: ulcerated lipoma	Did well after surgery
Priyadarshi et al[14], 2015	46 y. o. M with melena for 1 yr. Palpable, soft epigastric lump. Mild epigastric tendernessHgb = 5 mg/dL; coagulation parameters and chemistry WNL	EGD: large mass arising from posterior wall antrum with superficial ulceration. Unable to traverse pylorus due to obstruction. Abdominal CT: huge mass with lobulated surface projecting into gastric lumen with density consistent with fat. Tumor extended into pylorus and caused gastric outlet obstruction	Posterior wall of gastric antrumLaparotomy: Billroth I partial gastrectomy; 14 cm × 11 cm × 5 cm sessile broad based submucosal lipoma; path = mature adipocytes	No reported complications
Rao et al[15], 2013	60 y. o. M presented with melena, fatigue and pallor. Hgb = 7.2 g/dL	EGD: large, smooth, submucosal bulge along lesser curvature of stomach. Contrast enhanced abdominal CT: Well-defined, encapsulated, submucosal mass with attenuation of fat along lesser curvature of stomach	Laparotomy: large submucosal tumor excised via anterior gastrotomyPathology: 15 cm × 12 cm submucosal tumor with a focal ulcer. Microscopy demonstrates submucosal lipoma	Presently asymptomatic
Regge et al[16], 1999	52 y. o. M presented with hematemesis and melena. Hgb = 5.5 g/dL	EGD: 3.5-cm-wide, round, pale-pink formation on anterior gastric antrum with oozing superficial ulcer. Hemostasis achieved with dilute epinephrine injection. Abdominal USD: 4-cm-wide hyperechoic antral lesion with distinct margins. Abdominal CT with IV contrast: 4-cm-wide, well-circumscribed, antral lesion with density of fat. Abdominal MRI: Confirmed fat-tissue signal in mass by hyperintensity on T1-weighted images and marked signal reduction on sequences performed with fat suppression	Laparotomy: Antrectomy and gastrojejunal anastomosis via a Roux-en-Y loop. Pathology: lipoma	N.A
Sadio et al[17], 2010	44 y. o. M with medical history of hypertension, obesity, and sleep-apnea, presented with fatigue and intermittent melena for 1 mo. Physical exam revealed pallor. Hgb = 7.8 g/dL	EGD: 4-cm-wide, yellowish, submucosal mass in gastric fundus with central overlying ulceration. EUS: hyperechoic submucosal mass. Abdominal CT: homogeneous, well-circumscribed mass in fundus with density of fat	Surgery: partial gastric resectionPathology: submucosal lipoma	Did well and discharged 10 d postoperatively
Singh et al[18], 1987	40 y. o. M with melena, pyrexia, chills, and weakness. BP = 100/70 mmHg, pulse = 106/min, temp = 39 °C, abdomen-soft, nontender, no palpable mass. Hgb = 4.0 g/dL	EGD: huge polypoid tumor in gastric body along greater curve. Multiple small superficial ulcers in antrumEGD biopsies: Mildly inflamed, mature adipose tissueUGI series: large gastric tumor	Gastric body along greater curveLaparotomy: smooth mass in gastric body and antrum. Multiple small ulcerations. Underwent subtotal gastrectomy and gastrojejunostomy. Pathology: 18 cm × 10 cm × 10 cm encapsulated lipoma	Discharged 2 wk postoperatively. Asymptomatic for 1 yr.
Youssef et al[19], 1999	54 y. o. nonalcoholic F presented with melena and dizzinessPhysical exam: stable vital signs, abdominal tenderness without peritoneal signs. Hgb = 9.2 g/dL	EGD: submucosal protrusion with mucosal erosion along greater curvature in body and antrumAbdominal USD: homogeneous, hyperechoic mass in submucosa of posterior gastric wall. Abdominal CT: homogeneous, 5.1 cm × 3.7 cm lesion with density of fat in posterior gastric wall	Laparotomy: with full-thickness resection of lesionPathology: 5.2 cm × 3.8 cm × 3.2 cm submucosal lipoma	Uneventful recovery
Abdominal pain
Alberti et al[20], 1999	11 y. o. F with periumbilical and RLQ abdominal pain for 3 yr. Outpatient UGI series revealed multiple filling defects in gastric antrum and body. Normal physical examination. Abdomen was soft with no palpable mass. No fecal occult bloodNormal routine blood studies. Normal iron studies	EGD: multiple, large, soft, masses protruding into gastric body and antrum with normal overlying mucosa. Gastric biopsies: normal mucosa. Abdominal USD: multiple, homogeneous, well-encapsulated, submucosal masses with attenuation characteristic of fat. Abdominal MRI: solid, hyperintense formations with signal characteristic of fat in gastric body and antrum. Percutaneous transgastric ultrasound guided biopsy: features of lipoma with mild inflammatory infiltrate	Gastric body and antrum. No treatment because became asymptomatic	“Pain progressively relieved”Follow-up MRI of abdomen: no change
Hamdane et al[21], 2012	51 y. o. M with epigastric painN.A	EGD: soft, large, ulcerated, submucosal mass in antrumEndoscopic biopsies: nonspecific inflammation of gastric mucosa. Abdominal CT: Round, well-circumscribed, low-attenuation, 9-cm-wide, gastric mass	Surgery: total gastrectomy. Pathology: 9 cm × 7.5 cm × 5 cm., mature adipocyte proliferation with variation of cell size in a fibro-myxoid background. Immunohistochemistry: positive to anti-HGMA2, but not S-100, or CD34, No MDM2 or CDK4 amplification, consistent with lipoma	Uneventful recovery. No symptoms at 1 yr follow-up
Neto et al[22], 2012	63 y. o. M history of dyslipidemia, and hypertension with upper abdominal pain. Physical exam reveals a palpable, moveable upper abdominal massNormal routine laboratory tests	Abdominal USD: large echoic mass compatible with an expansive lesion in gastric antrum. EGD: large bulging mass in posterior gastric wall with three ulcerated areasEndoscopic biopsies: necrotic mucosaAbdominal CT: well-defined, homogeneous, oval mass located within the posterior gastric wall that compressed descending duodenum and had the density of fat	Posterior gastric wall. Laparotomy with a subtotal gastrectomy and D1 lymphade-nectomy with Roux-en-Y reconstruction: 12 cm × 8 cm × 6 cm, lipoma with mature, well differentiated adipocytes surrounded by a fibrous capsule with 3 ulcerative lesions of 0.5 cm, 1 cm, and 1.4 cm	Uneventful recovery with discharge 7 d postoperatively
Ramaraj et al[23], 2012	52 y. o. M with dyspepsia, anorexia, and early satiety for 6 mo. Gastric ulcer 5 yr earlier. Iron deficiency anemia: Hg = 11.5 g/dL, ferritin = 5 ng/mL	Colonoscopy: within normal limits. EGD: Extrinsic indentation in distal stomach with smooth overlying mucosa. Endoscopic biopsy: normal mucosaCT abdomen: 15 cm × 14 cm fatty tumor in distal stomach	AntrumSubtotal gastrectomy: Submucosal antral lipoma with central ulceration	No postoperative complications. Asymptomatic at 4 wk of follow-up
Zak et al[24], 2006	58 y. o. M with intermittent upper abdominal discomfort, early satiety, smoking, hyperlipidemia, obesity, PTSD, and depression. Has iron deficiency anemia	EGD: 10 cm × 6 cm smoothly lobulated, submucosal mass in gastric antrum along greater curvature. Chronic inflammation and intestinal metaplasia of gastric mucosa. EUS: hypoechoic submucosal mass surrounded by a hyperechoic layer in posterior wall of stomach, consistent with encapsulated lipoma. Abdominal CT: homogeneous, round, sharply-defined, encapsulated, submucosal lesion with characteristic density of fat	Gastric antrum along the greater curvatureLaparotomy: resection only of the encapsulated massPathology: 10 cm × 6 cm lipoma	Uneventful recovery with discharge on day 7. Follow-up abdominal CT 2 mo later revealed no abnormalities
Predominantly nausea and vomiting or obstructive symptoms
Aslan et al[25], 2015	77 y. o. M with nausea and vomiting,and dyspepsia. Complete blood count and comprehensive metabolic panel: WNL	EGD: submucosal mass with normal overlying mucosa extending into antrum along lesser curve	Endoscopic submucosal resection of 9-cm-long lipoma with an intact capsule	Discharged after 3 d. Resolution of symptoms at 6 mo of follow-up. Repeat endoscopy did not reveal a mass
Lin et al[26], 1992	77 y. o. F with nausea, vomiting, abdominal pain for 3 wk and 7-kg-weight-loss. Dehydrated and generalized mild abdominal tenderness. Rectal exam: fecal occult blood	UGI series: large polypoid gastric mass intussuscepting into duodenum. Abdominal USD: suspected intussusception. EGD: inadequate examination. Differential of gastric torsion vs intussusception	Laparotomy: large necrotic polypoid intussuscepting mass arising in stomach. Polyp resected at its base. Pathology: large polypoid lipoma	Ultimately recovered and was discharged
Mouës et al[27], 2002	72 y. o. M with anorexia, early satiety, nausea, and involuntary weight loss. No overt GI bleeding. Left lung lobectomy for bronchial lung cancer 10 yr earlier. Hemoglobin = 4.7 g/dL	EGD: gastric mucosal hypertrophy extending into duodenum. Abdominal USD: hyperechoic mass in small intestine, consistent with lipoma, with likely intussusception. CT abdomen: low attenuation intraluminal tumor compatible with small intestinal lipoma	Laparotomy: large pedunculated tumor intussuscepting into jejunum. Mass reduced back into stomach. Gastrostomy revealed 10 cm × 5 cm superficially ulcerated gastric lipoma. Mass excised. Pathology: mature adipose tissue	Uneventful recovery
Nasa et al[28], 2016	56 y. o. F with dyspepsia and occasional vomiting for 1 yr. Mild epigastric tenderness	EGD: smooth 5-cm-wide antral bulge with overlying normal mucosa. Positive cushion sign. Endoscopic biopsy: chronic active gastritis from Helicobacter pylori. EUS: homogeneous, hyperechoic, mass arising from layer 3 of gastric wall, compatible with lipoma. Abdominal CT: homogeneous, 6-cm-wide, oval mass in antropyloric region, with density of fat	Antrum and pylorus along lesser curveLaparotomy: Excision of 6 cm wide, encapsulated tumor along lesser curve of stomach	Did well and discharged. Asymptomatic at 6 mo
Treska et al[29], 1998	61 y. o. M with intermittent vomiting for several days. History of gastric ulcer N.A	UGI series: spherical, smooth, 4.0 cm × 4.5 cm defect in gastric antrum. EGD: protruding, yellowish tumor in prepylorus. Two ulcers above tumor. Abdominal ultrasound: 7 cm × 6 cm × 5 cm echogenic defect in wall of gastric antrum. Abdominal CT: prepyloric intramural lipoma	Gastric antrum. Laparotomy: 7.0 cm × 6.0 cm tumor in prepylorus. Tumor resection of lipoma with performance of Billroth II	Discharge 12 d postoperatively. No GI symptoms 8 mo after surgery
Lipoma discovered incidentally in work-up for other condition
Al Shammari et al[30], 2016	41 y. o. M presented for morbid obesity with a BMI of 43.9 kg/m2 and history of obstructive sleep apnea. Normal routine blood tests	Abdominal ultrasound: liver span of 18.8 cm.EGD: rounded 3 cm × 3 cm mass in antrum with normal overlying mucosa. Positive cushion sign. Abdominal CT: 3.5 cm × 3.0 cm lesion in stomach suspicious for lipoma	Antrum. Laparoscopy: Intragastric submucosal mass excised from inside stomach after gastrostomy. Sleeve gastrectomy then performed for morbid obesity. Pathology: 4 cm × 3 cm × 2 cm lipoma	Discharged 4 d postoperatively. Asymptomatic at 2 wk of follow-up
Hyun et al[31], 2002	22 y. o. M who underwent abdominal CT as preoperative evaluation of retroperitoneum before orchiectomy for testicular cancer. N.A	Abdominal CT: large gastric mass with attenuation of fat projecting into gastric lumen. EGD: large, soft, sessile mass on greater curve of stomach with overlying pink mucosa. Positive cushion sign. Endoscopic biopsies: normal mucosa. EUS: Submucosal mass with less echogenicity than expected for lipoma	Surgical resection: 12 cm × 9 cm × 2.5 cm mobile mass resected. Pathology: Submucosal gastric lipoma	Doing well at 2 mo follow-up
López - Zamudio et al[32], 2015	59 y. o. M who underwent abdominal CT performed during episode of acute alcoholic pancreatitis revealed probable pyloroduodenal intussusception of a tumor with attenuation suggestive of fat. Hgb = 9.3 g/dL	EGD: 8 cm long polypoid mass impeding flow near pylorus. EGD biopsy: gastritis and incomplete intestinal metaplasia. Repeat EGD: greater curve posterior wall large pedunculated polyp with central ulcerationRepeat EGD biopsies: chronic gastritis, focal ulceration intestinal metaplasia and Helicobacter pylori infection. EUS: 5.6 cm × 4.9 cm mass in gastric antrum in muscular layer	Surgery: 5 cm × 5 cm tumor in anterior wall of gastric antrum. Underwent antroduodenectomy with gastroduodenal anastomosis and Roux-en-Y	No postoperative surgical complications. Asymptomatic at 18 mo of follow-up

PMH: Previous medical history; GI: Gastrointestinal; y.o.: Years old; M: Male; F: Female; Hgb: Hemoglobin; BP: Blood pressure; EGD: Esophagogastroduodenoscopy; CT: Computerized tomograph; EUS: Endoscopic ultrasound; UGI: Upper gastrointestinal; USD: Ultrasound; N.A: Not applicable; NSAID: Nonsteroidal anti-inflammatory drug; WNL: Within normal limits; IV: Intravenous; MRI: Magnetic resonance imaging; RLQ: Right lower quadrant; PTST: Post traumatic stress disorder; BMI: Body mass index.

Table 2 Risks factors for upper gastrointestinal bleeding among 32 patients with giant gastric lipomas

Parameter	mean ± SD of parameter in patients with bleeding	mean ± SD of parameter in patients without bleeding	Patients with bleeding: n with ulcer/total n (% with parameter)	Patients without bleeding: n with parameter/total n (% with parameter)	P value	OR	95%CI	Statistical test
Continuous variables
Patient age	54.9 ± 15.5 yr	53.8 ± 19.6 yr	-	-	0.87	NA	NA	Student’s t test
Lipoma size	7.1 cm ± 4.4 cm	9.3 cm ± 3.1 cm	-	-	0.16	NA	NA	Student’s t test
Dichotomous variables
Male sex	-	-	12/19 (63.2)	10/13 (76.9)	0.47	0.51	0.08-3.17	χ2 test
Ulcer overlying lipoma	-	-	16/19 (84.2)	4/13 (30.8)	0.004	12.0	1.72-101.9	Fisher’s exact test

UGI: Upper gastrointestinal; P: Probability; NA: Not available.

Table 3 Distinctive features of giant gastric lipomas

Test/technique/parameter	Distinctive characteristic	Pathophysiology	Ref.
Age	Average age = 54.5 ± 17.0 years old		Current Report
Gender ratio	Male-to-Female ratio approximately 2:1	Unknown (sexual hormones?)	Current Report
Lipoma size	Average maximal dimension = 7.9 cm × 4.1 cm		Current Report
Most common clinical presentation	19 of 32 presented with acute UGI bleeding	Postulated from ulcer at tip of lipoma caused by rubbing/trauma of tip against gastric wall contralateral to base of lipoma	Current Report
EGD	Smooth bulge covered by normal mucosa	Submucosal (or occasionally subserosal) location. No tumor invading mucosa due to benignity	Neto et al[22], 2012, Thompson et al[36], 2003
	Most commonly located in gastric antrum		Thompson et al[36], 2003, Menon et al[40], 2014
	Yellowish hue	Yellow color of adipose tissue in submucosa transmitted to mucosal surface	Menon et al[40], 2014, Chen et al[41], 2014
	Broad base	Rarely pedunculated	Singh et al[18], 1987
	Cushion or pillow sign: easily deforms like a cushion with mild pressure applied against it by an endoscopic probe (closed biopsy forceps).	Lipoma consists of soft, compressible tissue.	De Beer et al[37], 1975, Hwang et al[38], 2005
	Tenting sign: Mucosa easily retracts after it is grasped and gently pulled with a forceps	Mucosa separates from submucosa when gently pulled via forceps because lipoma has fibrous capsule and does not infiltrate into adjacent tissue	Priyadarshi et al[14], 2015
	Naked fat sign: repeated biopsies at same site reveals yellow fatty tissue	Multiple biopsies at same site (using well technique) exposes submucosal lipomatous tissue	Chen et al[41], 2014, Patrick et al[42], 2007
	Moderately frequent focal central ulceration of mucosa	Likely secondary to giant lipoma abutting and rubbing against contralateral gastric wall. Ischemia may also contribute to ulceration.	Kumar, et al[8], 2015, Thompson et al[36], 2003
Highly useful diagnostic test for lipomas	Typically strongly suggestive of diagnosis	Demonstrates anatomy of mass. Shows if ulcerated or intussuscepting mass. Characteristic findings: yellow hue, smooth overlying mucosa, relatively homogeneous, round margins. Exhibits pillow, tenting or naked fat signs.	Current Report
Endoscopic biopsies	Standard endoscopic biopsies usually reveal only normal mucosa and insensitive for pathologic diagnosis.	Standard endoscopic biopsies typically sample superficial mucosa and miss deeper submucosal lipoma.	Current Report, Neto et al[22], 2012
	Techniques to increase yield of endoscopic biopsies; use jumbo forceps for endoscopic biopsies; or well technique (repeated endoscopic biopsies at same mucosal site).	Repeated biopsies at same site permits sampling of deeper (submucosal) tissue	Wang et al[47], 2015
Abdominal CT	Submucosal mass	Typically submucosal, occasionally subserosal, and never mucosal.	Beck et al[3], 1997
	Well-circumscribed with well-defined edges	Characteristically has a firm fibrous capsule with no invasion through capsule due to benignity	Thompson et al[36], 2003
	Typically solitary	Multiple gastric lipomas are very rare	Park et al[48], 1999, Skinner, et al[49], 1983
	Homogeneous	Composed of homogeneous lipocytes	Park et al[48], 1999, Alkhatib et al[50], 2012
	Densitometry of -80 to -120 HU (Hounsfield units).	Characteristic of adipose tissue	Alberti et al[20], 1999
Highly useful as diagnostic test for gastric lipomas	Demonstrates characteristic findings in about 95% of cases.	Characteristic findings: well-circumscribed, submucosal, homogeneous mass with an attenuation characteristic of fat.	Current Report
EUS	In third layer of gastric wall	Typically submucosal (rarely subserosal)	Chen et al[43], 2011
	Hyperechoic (bright)		Alkhatib et al[50], 2012, Eckardt et al[51], 2012
EUS-guided needle biopsy or endoscopic mucosal resection	EUS guidance used to obtain diagnostic deep (submucosal) biopsies	Deep biopsies permit sampling of submucosal lipomas	Alkhatib et al[50], 2012, Karaca et al[52], 2010
Transcutaneous abdominal ultrasound	Not very useful for gastric lipomas.	Supplaned by abdominal CT or EUS for evaluating suspected gastric lipomas	Current Report
Upper gastrointestinal series	Mostly obsolete test	CT is a superior alternative	Current Report
Histopathology	Diagnostic features	Rounded, plump cells with abundant clear, homogeneous cytoplasm containing fat, eccentric nuclei, mature adipocytes with no lipoblasts, scant stroma, rare inflammatory cells.	Current Report
Imunohistochemistry	Reveals no MDM2 or CDK4 gene amplification.	Distinguishes lipoma from liposarcoma.	Shimada et al[45], 2006, Boltze et al[46], 2001
Immunohistochemistry	Lipoma stains positively for CD4	Indicates spindle-cell lipoma variant	Lau et al[39], 2015

UGI: Upper gastrointestinal; EGD: Esophagogastroduodenoscopy; CT: Computerized tomography; EUS: Endoscopic ultrasound.