Introduction

Peutz-Jeghers Syndrome (PJS) is a rare autosomal dominant syndrome which is characterized by gastrointestinal hamartomatous polyps and mucocutaneous pigmentation [1, 2], first described by Peutz in 1921 [3].

A hamartomatous polyp without associated mucocutaneous pigmentation or a family history of PJS is diagnosed as a solitary Peutz-Jeghers type hamartomatous polyp [4]. As compared with PJS, Peutz-Jeghers type hamartomatous polyps are diagnosed with a lower risk of cancer [5] and have been regarded as a different disorder from PJS.

We report two cases with a solitary Peutz-Jeghers type hamartomatous polyp treated by endoscopic mucosal resection.

Case Presentations

Case 1 is an 84-year-old Japanese man with previous medical history of hypertension, chronic hepatitis C infection, idiopathic thrombocytopenic purpura and colon polyps (tubular adenoma and tubulovillous adenoma). He had no mucocutaneous pigmentation or family history of PJS. An upper gastrointestinal endoscopy revealed a lobular polyp measuring 14 mm in diameter, in the superior duodenal angle (Figure 1). Endoscopic mucosal resection was performed without complication and histological examination showed findings suggestive of a hamartomatous polyp--branching bundles of smooth muscle fibers covered by hyperplastic duodenal mucosa--with a focus of well-differentiated adenocarcinoma (Figure 2). A colonoscopy and small-intestinal follow-through showed no other polyps.

Figure 1
figure 1

A lobular duodenal polyp measuring 14 mm in diameter was detected in the superior duodenal angle.

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Figure 2
figure 2

Histological examination showed findings suggestive of a hamartoma: branching bundles of smooth muscle fibers covered by hyperplastic duodenal mucosa, with a focus of well-differentiated adenocarcinoma. Hematoxylin and eosin staining (objective 10 ×).

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Case 2 is a 76-year-old Japanese man who had been treated for prostate, rectal and lung cancer, with no mucocutaneous pigmentation or family history of PJS. An upper gastrointestinal endoscopy revealed a duodenal polyp measuring 15 mm in diameter in the second part of his duodenum (Figure 3). Endoscopic mucosal resection was performed, and histological examination showed findings suggestive of a hamartomatous polyp (Figure 4). A colonoscopy and small-intestinal follow-through showed no other polyps. After the endoscopic treatment, concomitant liver and thyroid cancers were found.

Figure 3
figure 3

Pedunculated duodenal polyp measuring 15 mm in diameter in the second part of the duodenum.

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Figure 4
figure 4

Histological examination showed findings suggestive of a hamartoma without malignant components. Hematoxylin and eosin staining (objective 10 ×).

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Discussion

As compared with PJS, Peutz-Jeghers type hamartomatous polyps are diagnosed at a more advanced age, in the absence of mutation of the STK11/LKB-1 gene, and without familial history and mucocutaneous pigmentation [5].

Previous reports showed that polyps due to PJS had 3-6% of neoplastic change, such as adenomas or carcinomas [4–18]. A search of case reports on the MEDLINE database up to July 2010, using the terms "hamartomatous polyp" and "duodenum", and of reference lists of published articles (including our cases), showed 27 patients with a solitary Peutz-Jeghers type hamartomatous polyp in the duodenum (Table 1). Although solitary Peutz-Jeghers type hamartomatous polyps have been considered to show a lower potential for malignant transformation as compared to PJS, three cases (including ours) of solitary Peutz-Jeghers type hamartomatous polyps with malignant components have been reported since 2008, and the total malignant transformation rate of solitary Peutz-Jehgher type hamartomatous polyps was four out of 27 (14.8%). There were no significant tendencies of malignant transformation within the age or sex of the patient, or the location, size or endoscopic appearances of the polyp.

Table 1 Twenty-seven cases of solitary duodenal Peutz-Jeghers type hamartomatous polyps.
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The most serious problem in PJS is an increased risk of cancer in the gastrointestinal tract. The occurrence of cancer in the gastrointestinal tract has been reported in 20-25% of patients with PJS, and a risk of cancer in other organs has been also reported, including the ovary, breast, bladder, pancreas and thyroid [2, 19–22].

To the best of our knowledge, there have been no previous reports of patients with solitary Peutz-Jeghers type hamartomatous polyps presenting with malignancy in other organs. This is one of the reasons that solitary Peutz-Jeghers type hamartomatous polyps have been considered as a separate clinical entity from PJS. However, Case 2 in our report had duplicated malignancy in six organs. An overlap between solitary Peutz-Jeghers type hamartomatous polyps and PJS may need to be re-examined.

Our two cases were diagnosed in patients with an advanced age similar to previous reports, but they differ in the malignant alteration of a hamartomatous polyp and concomitant other cancers. Patients with duodenal Peutz-Jeghers type hamartomatous polyps should undergo colonoscopy and whole-body screening; duodenal solitary Peutz-Jeghers type hamartomatous polyps should preferably be treated by endoscopic or surgical resection.

Conclusions

We report two cases of duodenal solitary Peutz-Jeghers type hamartomatous polyp. Case 1 was a hamartomatous polyp with a focus of well-differentiated adenocarcinoma, and Case 2 was a hamartomatous polyp with five cancers in other organs. We advise that patients with duodenal solitary Peutz-Jeghers type hamartomatous polyps should preferably be treated with endscopic or surgical resection and whole-body screening.

Consent

Written informed consent was obtained from both patients for publication of these case reports and any accompanying images. Copies of the written consent are available for review by the Editor-in-Chief of this journal.