Author

Year

Age

Sex

Presentation

Location

EGD/Gross findings

Histology

Stains

Treatment

Follow-up

Duran Álvarez [6]

2017

68

F

Nausea and intermittent vomiting for 2 years;

White hard thickening of anterior antral wall found during laparoscopic cholecystectomy

Antrum

Slight prominence of antral mucosa without mass, ulcer, polyps, or stenosis. Diffuse thickening of the antral wall that measured 4 x 3 cm was identified. Submucosa showed areas of fat replacement and the overlying mucosa presented a slight superficial prominence of gastric folds.

Cribriform area of 1 x 0.5 cm, composed of dilated ducts and islands of Brunner-type glands supported in scant loose connective tissue with sparse chronic inflammatory infiltrates. Ducts and islands were embedded in disordered bundles of smooth muscle. Adjacent submucosa showed patchy lipomatosis, loose fibrosis, and dilated vascular spaces. Overlying mucosa presented chronic gastritis with foci of incomplete pancreatic and intestinal metaplasia without dysplasia or malignancy. No HP was identified.

Ki67 < 1%;

(-) CD 117;

(-) CD34;

(-) S-100;

(+) smooth muscle actin;

(+) CK7 in epithelial lining of dilated ducts

Partial gastrectomy and Roux-en-Y reconstruction

-

Massey [12]

2018

30

F

Abdominal pain,

CT showed narrowing of distal stomach and antrum and cystic lesion

Antrum

-

Gastric antral type mucosa and an underlying mass forming lesion consisting of scattered gastric type glands with focal metaplastic changes admixed with bundles of smooth muscle; focally active duodenitis present overlying lesional tissue. No dysplasia or malignancy.

(-) CD117;

(+) CD10 in scattered inflammatory cells, (-) CD10 in stroma cells surrounding entrapped glands;

(-) PAX-8 in glands;

CD34 highlights scatter vascular channels

Gastroduodenectomy

-

Bedir [4]

2018

26

F

Incidental finding during sleeve gastrectomy

Prepyloric

Intramural gray-white coloured mass lesion observed in 1.6 x 1.5 cm dimensions with irregular borders causes a protrusion in the serosal surface in the antrum

Glandular structures under the gastric mucosa and pancreatic acinar glands in muscularis propria between hypertrophied muscle bundles lined with columnar and flattened mucinous epithelium, some of which were cystically enlarged; no atypia or mitotic activity

(+) smooth muscle actin;

(+) CK7;

Low Ki-67 (1%);

p53 < 1%

Subtotal gastrectomy (for bariatric purposes and mass removal)

Arslan [1]

2018

5

F

Abdominal pain for 2 years, poor oral intake, fever; CT showed cystic lesion 30x28 mm in antrum

Pylorus

3.5 x 3 cm mass

Cysts and glandular structures lined by cuboidal to columnar epithelium surrounded by hypertrophic smooth muscle bundles; foreign body giant cells and xanthogranulomatous inflammation detected on the serosal surface

Exploratory laparotomy, mass excision, double-layer transverse anastomosis

Normal gastric anatomy on CT 3 months following

Huang [9]

2019

59

F

Intermittent upper abdominal pain for 1 year

Antrum

2 cm submucosal mass

Arrangement of glands was irregular, smooth muscle bundles wrapped around the glands, and a small number of lymphocytes were infiltrated

-

Endoscopic submucosal dissection

Kamrani [10]

2019

15

F

Nausea and vomiting for 2 years, unable to tolerate solid foods; CT confirmed gastric outlet obstruction

Distal antrum and proximal pylorus

3.3 x 2.7 x 2.2 cm submucosal mass with central umbilication protruding into the lumen of distal stomach, overlying gastric mucosa intact and unremarkable, sectioning through mass showed markedly thickened gastric wall with the ill-defined, variegated, fibrotic cut surface

Lobules of benign dilated duct-like structures, gastric-type glands, and Brunner-type glands surrounded by bundles of hypertrophic smooth muscle that penetrated through the muscularis propria of the antrum and pylorus with extension into the duodenal bulb; foci of pancreatic acinar tissue also present; some dilated ducts showed evidence of rupture with adjacent abscess, exuberant foreign body giant cell reaction, chronic inflammation, mural fibrosis, and organizing serositis. No evidence of malignancy.

Distal gastrectomy with gastroduodenostomy

Uneventful recovery

Quiroga [13]

2019

5

M

Incidentally discovered during evaluation of periumbilical lipoma

Antrum

Umbilized submucosal tumor, dependent on the muscular layer with a diameter of 1.6 x 0.8 cm

Benign lesion formed by abundant smooth muscle tissue … in which the gastric mucosa of irregular appearance is found, as well as small pancreatic islets. No evidence of malignancy.

Pancreatic islets (+) for chromogranin

Partial laparoscopic gastrectomy

Good postoperative evolution

Bamidele [3]

2020

26

F

Recurrent dyspepsia that radiated to L hypochondrium, bloating, nausea for 6 months

Antrum

Small (1-2 cm), firm, circular, umbilicated subepithelial antral nodule; mucosa overlying lesion appeared inflamed

Columnar epithelium overlying a lamina propria within which nests of Brunner glands that were separated by smooth muscle bundles and mucous glands. No cytologic atypia.

PPIs for 4 weeks.

Chose to follow & monitor due to absence of dysplasia or malignant cells on histology, the small size of the antral nodule, and resolution of symptoms with medical therapy

Symptoms resolved after 2 weeks with PPIs

Repeat EGD and biopsy 6 months later showed no significant change in size and no malignant transformation on histology; has remained asymptomatic

Anand [2]

2020

12

M

Episodic, dull-aching pain in LUQ for 1 month, occasional nonbilious vomiting

Antrum

Circumferentially thickened and bulky pylorus

Expansion of the submucosa and muscularis by smooth muscle cells, presence of Brunner’s glands

(+) PAS

(+) CK7

(-) synaptophysin

Pylorus completely excised, gastroduodenostomy performed with trans anastomotic tube

Asymptomatic after a year of follow up; PET scan 3 months after resection showed no FDG uptake