A Rare Case of Juvenile Polyposis Syndrome Mimicking Ménétrier's Disease.

There is a wide differential diagnosis within polyposis syndromes. Our case represents an interesting and diagnostically challenging diagnosis involving a 41-year-old male who presented with an incidental gastric mass on imaging and a colonic mass seen on colonoscopy. Following multiple endoscopic evaluations, histological analysis, and genetic testing, the patient was ultimately diagnosed with juvenile polyposis syndrome (JPS)/hereditary hemorrhagic telangiectasia (HHT) despite the initial suspicion for Ménétrier's disease. His disease course was complicated by an acute upper extremity thrombus and diagnosis of colorectal carcinoma. This case highlights the importance of a thorough evaluation when polyposis syndromes are suspected. Prompt and accurate diagnosis can aid in the treatment, surveillance, and prevention of colorectal carcinoma.