OBJECTIVE-Ménétrier's disease (MD) is a rare hypertrophic gastropathy characterised by giant rugal folds, hypochlorhydria, protein loss and a classic constellation of symptoms -nausea, vomiting, abdominal pain and peripheral oedema. It is considered a clinical diagnosis that, at times, may be difficult to establish. We propose firm diagnostic criteria for MD by delineating the clinicopathological features that best differentiate MD from its mimics. DESIGN-Forty-eight patients referred to Vanderbilt University Medical Center for consideration of enrolment in a clinical trial to treat MD patients with cetuximab were evaluated for a definitive diagnosis by assessment of clinical presentation, pertinent laboratory values and histopathological features.RESULTS-MD was confirmed in 25/48 (52%) of the patients. We designated the remaining 23 patients as mimics of MD; the most common diagnoses among the MD mimics were gastric polyps or polyposis syndromes (13/23, 57%). Gastric slides were available from 40 of 48 cases for detailed histological analysis (22/25 MD cases and 18/23 non-MD cases). Foveolar hyperplasia, glandular tortuosity and dilatation, and a marked reduction in parietal cell number were present in all 22 MD cases; lamina propria smooth muscle hyperplasia and oedema characterised most cases (18/22 and 19/22, respectively); more than half had prominent eosinophils (11/22) and/or plasma cells (12/22) in the lamina propria. The clinical presentation of MD patients was characterised by significantly younger age at onset, male predominance and increased vomiting compared to non-MD, and lower prevalence of anaemia compared to non-MD with polyps; there was trend towards increased frequency of peripheral oedema in MD versus non-MD.CONCLUSIONS-MD is most accurately diagnosed by clinicohistopathological analysis including esophagogastroduodenoscopy with gastric pH, appropriate laboratory tests (complete blood count, serum albumin, serum gastrin, H. pylori and cytomegalovirus serology) and full thickness mucosal biopsy of the involved gastric mucosa.Corresponding Author: Robert Coffey, robert.coffey@vanderbilt.edu, Tel: 615-343-6228, Fax: 615-343-1591 however, each has yielded inconsistent benefits, and none have been evaluated in a clinical trial. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] The only definitive treatment is total gastrectomy. A recently published clinical trial from our group reported that MD patients treated with cetuximab, a monoclonal antibody to the epidermal growth factor receptor (EGFR), showed significant clinical and biochemical improvement in all 7 patients that completed the one-month trial with subsequent histological reversion to normal or near normal in 4 of these patients. [27][28][29] The pathogenesis of MD is related to increased EGFR signalling in the stomach. In vitro, administration of transforming growth factor-α (TGF-α), one of seven mammalian EGFR ligands, stimulates gastric epithelial growth, inhibits acid production and increases mucin levels...