Solitary Peutz-Jeghers type polyps are characterized by a hamartomatous polyp of the gastrointestinal (GI) tract in a patient without mucocutaneous pigmentation, family history of Peutz-Jeghers syndrome, or STK11/LKB1 mutations. Histologically identical to the polyps in Peutz-Jeghers syndrome, these sporadic polyps can arise anywhere along the GI tract, with typical arborizing smooth muscles extending from the muscularis mucosa. While the lining mucosa is generally the same as the organ in which it arises, gastric pyloric and osseous metaplasia have been reported in intestinal polyps in Peutz-Jeghers syndrome. Herein, the authors report the first case of a small intestinal solitary Peutz-Jeghers type polyp with gastric antral and fundic gland lining mucosa. A 43-year-old male was admitted for small bowel obstruction. Diagnostic laparoscopy revealed jejuno-jejunal intussusception with an associated polyp measuring 7.2 cm. Histological examination showed a hamartomatous polyp with arborizing smooth muscle bundles extending from the muscularis mucosae. The polyp was lined by non-dysplastic gastric antral and fundic gland mucosa, and was sharply demarcated from the adjacent non-polypoid intestinal mucosa. Colonoscopy, esophagogastroduodenoscopy and small bowel enteroscopy revealed no additional polyps or masses. Thorough investigation of the patient's family history was negative for Peutz-Jeghers syndrome or mucocutaneous pigmentation. Molecular analysis of the lesion was negative for STK11/LKB1 mutations. A diagnosis of solitary Peutz-Jeghers type polyp of the small bowel with gastric antral and fundic gland mucosal lining was rendered.
Keywords: Peutz-Jeghers syndrome; STK11/LKB1; dysplasia; metaplasia; solitary Peutz-Jeghers type polyp.