PJ polyps have characteristic histological features, with a frond-like elongated epithelial component and cystic gland dilatation extending into the sub-mucosa or muscularis propria, and arborising smooth muscle extending into polyp fronds.
Areas do show larger cystic spaces which are a typical feature.
The epithelial component consists of the native epithelium -- in this case, as the polyp arises in the stomach and foveolar epithelium lines the glands.
A closer view of the hyperplastic foveolar epithelium that lines the glands is seen here.
The glandular cells contain abundant mucin and small nuclei lined up against the basement membrane.
In some areas, there are more elongated nuclei - perhaps some adenomatous transformation has occurred.
Arborizing smooth muscle is present between glands (arrows). Polyps in the stomach and colon often have less dramatic smooth muscle compared to their small intestinal counterparts.
Peutz-Jeghers Syndrome (PJS) is an autosomal dominant condition characterized by polyps throughout the gastrointestinal tract and mucocutaneous pigmentation. The majority of patients have a causative mutation in the serine threonine kinase STK11 gene, which is located at 19p13.3. JPS is the most common polyposis syndrome after familial adenomatous polypsis (FAP).
PJ polyps exhibit the following key features: (1) hyperplastic epithelium appropriate to the anatomic site; (2) arborizing bands of smooth muscle.
Patients have an increased risk of cancers, particularly for colorectal, breast, small bowel, gastric, and pancreatic cancer. In women, mucinous neoplasms of the ovary and ovarian sex-cord tumors with annular tubules occur. It is not fully certain whether some or all of the GI neoplasms malignancies originate from the hamartomas or from coexisting adenomas or normal mucosa. Although the hamartoma-adenoma-carcinoma sequence has not been fully elucidated, there are clearly documented cases of malignant transformation of pre-existing PJ polyps (Hizawa, Ben Brahim).
The location of the gastrointestinal malignancies does not always correlate with the location of the hamartomatous polyps. Overall, the relative cancer risks vary between 4.8 and 18 compared with the general population, with lifetime cumulative cancer risks up to 93% (van Lier).
Mucocutaneous pigmented lesions tend to arise in infancy, occurring around the mouth, nostrils, perianal area, fingers and toes, and the dorsal and volar aspects of hands and feet. They may wane after puberty but tend to persist in the buccal mucosa (Beggs). Polyps arise throughout the gastrointestinal tract, and are most frequent in the small bowel (60–90%)and colon (50–64%). Other GI sites include the stomach, duodenum and appendix. Interestingly, polyps may also be found at extra-intestinal sites such as the gallbladder, bronchi, bladder and ureter (Vogel).
In childhood, the symptoms of JPS are largely due to mechanical issues. For example, polyps in the jejunum and ileum may lead to intussusception and obstruction, and polyps in the rectum can prolapse and bleed. In adulthood, the morbidity of JPS is due to the development of cancer in the GI tract as well as extra-intestinal sites (Iacobuzio).
Surveillance is important for two reasons: to detect large polyps which potentially could cause intussusception/obstruction or bleeding, and to detect cancer at an early stage.
JPS consists of two main features: hamartomatous polyps throughout the GI tract and mucocutaneous pigmented macules.
The most common sites of polyp formation are the small intestine and colon.
Beggs AD, et al. Peutz-Jeghers syndrome: a systematic review and recommendations for management. Gut. 2010 Jul;59(7):975-86.
Ben Brahim E, Jouini R, Khayat O et al. Adenomatous transformation in hamartomatous polyps cases of two patients with Peutz-Jeghers syndrome. Int J Colorectal Dis. 2009 Nov;24(11):1361-3. Epub 2009 May 8.
Hizawa K, Iida M, Matsumoto T et al. Neoplastic transformation arising in Peutz-Jeghers polyposis.
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Iacobuzio-Donahue CA, Montgomery EA. Gastrointestinal and Liver Pathology: Foundations in Diagnostic Pathology. Philadelphia, PA: Elsevier; 2005: 349-354.
Vogel T,et al. Extraintestinal polyps in Peutz–Jeghers syndrome: presentation of four cases and review of the literature. Deutsche Peutz–Jeghers-Studiengruppe. Int J Colorectal Dis 2000;15:118–23.
van Lier MG,et al. Am J Gastroenterol. High cancer risk in Peutz-Jeghers syndrome: a systematic review and surveillance recommendations. 2010 Jun;105(6):1258-64.