A case of juvenile polyposis of the stomach with multiple early gastric cancers

Gastric Juvenile Polyposis with Intramucosal Cancer Diagnosed by Magnifying Endoscopy with Narrow-band Imaging

Although gastric juvenile polyposis (GJP) often coexists with gastric cancer, a preoperative accurate diagnosis is still difficult to obtain. A 70-year-old woman was referred for epigastralgia and anemia. Esophagogastroduodenoscopy with a conventional endoscope showed numerous gastric polyps with no cancerous findings. Magnifying endoscopy with narrow-band imaging (M-NBI) showed cancerous findings, and a target biopsy revealed adenocarcinoma. Histopathological findings after endoscopic resection confirmed a diagnosis of juvenile polyposis with intramucosal adenocarcinoma. Genetic analyses revealed a germline pathogenic variant of SMAD4. A target biopsy using M-NBI and endoscopic resection proved useful for confirming the preoperative diagnosis of coexisting cancerous lesions in GJP.

Massive juvenile polyposis of the stomach in a family with SMAD4 gene mutation

Relatively little is known on the genotype-phenotype correlations between SMAD4 gene mutations, juvenile polyposis of the intestine and Hereditary Hemorrhagic Teleangectasia. We describe a family in which the proband (a 46-year old woman) had massive polyposis of the stomach-leading to surgery-with high-grade dysplasia at histology. Molecular analysis was carried out using Next Generation sequencing techniques with Miseq Illumina Platforms and a minimal coverage of 40 reads. In the proband, the analysis showed the presence of a truncating mutation in the SMAD4 gene (c.1213dupC, a variant previously associated with juvenile polyposis and Hereditary Hemorrhagic Teleangectasia). The same mutation was detected in two other members of the family (father and brother of the proband), who showed massive polypoid involvement of the stomach at gastroscopy. By taking the family history, subtle evidence of Hereditary Teleangectasia was found (nasal bleeding and arterovenous malformations) in the three gene carriers. Colonoscopy showed polyp occurrence in all three affected members with SMAD4 mutation, with prevalence of adenomatous lesions in one (father), of hamartomas in the brother, and of a mix of histological types in the proband. The main features of the family can be summarized as follows: (A) In hereditary juvenile polyposis, lesions of different histology can be detected at colonoscopy; (B) In the gene carriers of SMAD4 mutations, lesions of the stomach require careful surveillance and, when necessary, surgical interventions; (C) Signs and symptoms of Hereditary Hemorrhagic Teleangectasia should be suspected (and searched) in individuals with SMAD4 constitutional mutations.

Malignant tumors associated with juvenile polyposis syndrome in Japan

PURPOSE

The risk of malignant tumors developing in association with juvenile polyposis syndrome (JPS) was evaluated to explore the optimal treatment for this rare disease.

METHODS

We reviewed the data on JPS cases reported in Japan between January, 1971 and March, 2016.

RESULTS

A total of 171 cases were evaluable. Of these 171 patients, 83 (48.5%) were female and the median age at diagnosis was 28 years (range 1-80 years). The polyps were located in the stomach alone (n = 62; 36.3%), in the stomach and intestine (n = 47; 27.4%), or in the colorectum alone (n = 62; 36.3%). The sites of malignant tumors were the stomach (n = 31), colorectum (n = 29), small intestine (n = 2), breast (n = 1), and thyroid (n = 1). The lifetime risk (at 70 years) of any malignant tumor was 86.2%. The lifetime risk of gastric cancer was 73.0% and that of colorectal cancer was 51.1%. The risk of these cancers developing was dependent on the type of polyp distribution.

CONCLUSIONS

Long-term surveillance of the stomach and colorectum based on the phenotype of JPS seems a reasonable approach to monitor these patients for the development of malignant tumors.