Cellular and molecular characteristics of stromal Lkb1 deficiency-induced gastrointestinal polyposis based on single-cell RNA sequencing

Liver kinase B1 (Lkb1), encoded by serine/threonine kinase (Stk11), is a serine/threonine kinase and tumor suppressor that is strongly implicated in Peutz-Jeghers syndrome (PJS). Numerous studies have shown that mesenchymal-specific Lkb1 is sufficient for the development of PJS-like polyps in mice. However, the cellular origin and components of these Lkb1-associated polyps and underlying mechanisms remain elusive. In this study, we generated tamoxifen-inducible Lkb1flox/flox;Myh11-Cre/ERT2 and Lkb1flox/flox;PDGFRα-Cre/ERT2 mice, performed single-cell RNA sequencing (scRNA-seq) and imaging-based lineage tracing, and aimed to investigate the cellular complexity of gastrointestinal polyps associated with PJS. We found that Lkb1flox/+;Myh11-Cre/ERT2 mice developed gastrointestinal polyps starting at 9 months after tamoxifen treatment. scRNA-seq revealed aberrant stem cell-like characteristics of epithelial cells from polyp tissues of Lkb1flox/+;Myh11-Cre/ERT2 mice. The Lkb1-associated polyps were further characterized by a branching smooth muscle core, abundant extracellular matrix deposition, and high immune cell infiltration. In addition, the Spp1-Cd44 or Spp1-Itga8/Itgb1 axes were identified as important interactions among epithelial, mesenchymal, and immune compartments in Lkb1-associated polyps. These characteristics of gastrointestinal polyps were also demonstrated in another mouse model, tamoxifen-inducible Lkb1flox/flox;PDGFRα-Cre/ERT2 mice, which developed obvious gastrointestinal polyps as early as 2-3 months after tamoxifen treatment. Our findings further confirm the critical role of mesenchymal Lkb1/Stk11 in gastrointestinal polyposis and provide novel insight into the cellular complexity of Lkb1-associated polyp biology. © 2024 The Pathological Society of Great Britain and Ireland.

Changes of gut microbiota and short chain fatty acids in patients with Peutz-Jeghers syndrome

Peutz-Jeghers Syndromeis a rare autosomal dominant genetic disease characterized by gastrointestinal hamartomatous polyps and skin and mucous membrane pigmentation. The pathogenesis of PJS remains unclear; however, it may be associated with mutations in the STK11 gene, and there is currently no effective treatment available. The gut microbiota plays an important role in maintaining intestinal homeostasis in the human body, and an increasing number of studies have reported a relationship between gut microbiota and human health and disease. However, relatively few studies have been conducted on the gut microbiota characteristics of patients with PJS. In this study, we analyzed the characteristics of the gut microbiota of 79 patients with PJS using 16 S sequencing and measured the levels of short-chain fatty acids in the intestines. The results showed dysbiosis in the gut microbiota of patients with PJS, and decreased synthesis of short-chain fatty acids. Bacteroides was positively correlated with maximum polyp length, while Agathobacter was negatively correlated with age of onset. In addition, acetic acid, propionic acid, and butyric acid were positively correlated with the age of onset but negatively correlated with the number of polyps. Furthermore, the butyric acid level was negatively correlated with the frequency of endoscopic surgeries. In contrast, we compared the gut microbiota of STK11-positive and STK11-negative patients with PJS for the first time, but 16 S sequencing analysis revealed no significant differences. Finally, we established a random forest prediction model based on the gut microbiota characteristics of patients to provide a basis for the targeted diagnosis and treatment of PJS in the future.

Clinicopathologic comparison between sporadic and syndromic Peutz-Jeghers polyps

Peutz-Jeghers polyps (PJPs) are hamartomatous polyps that may define patients with Peutz-Jeghers syndrome (PJS), a rare inherited polyposis syndrome with high cancer risk. However, the clinical significance of 1-2 sporadic PJPs (without other PJS stigmata) regarding malignant potential and identification of new PJS probands is still unclear. We identified 112 patients with 524 histologically confirmed PJPs and categorized them based on polyp number into syndromic (n = 38) if ≥3 PJPs or diagnosed PJS, solitary (1 PJP, n = 61), and intermediate (2 PJPs, n = 13). Clinicopathologic features, including presence of dysplasia in the polyp and development of neoplasia in the patient, were compared on a per-patient and per-polyp basis. Whereas patients with solitary and intermediate PJPs were not different from each other, patients with syndromic PJPs were, in multivariate analysis, younger (P = .001) and more likely to develop neoplasia (P = .02) over a 62.6-months median follow-up than patients with sporadic PJPs. On an individual polyp basis, syndromic PJPs were more likely, in multivariate analysis, to occur in the small intestine (P < .001), but less likely to harbor metaplasia (P = .03) or dysplasia (P = .001), than sporadic PJPs. Dysplasia and metaplasia were more likely in larger PJPs, by multivariate analysis (P = .007 and P < .001, respectively). These data suggest that strict criteria for PJS (including ≥3 PJPs), as currently used, stratify patients into distinct groups with significant differences in clinicopathologic parameters, particularly regarding risk of neoplasia. However, sporadic PJPs exhibit characteristics such as dysplasia and are thus important to recognize and diagnose but perhaps as heralding only a forme fruste PJS.

[A man with brown discolorations]

A 58-year-old man presents with spontaneous brown discolorations of his mouth and hands. Our differential diagnosis included Peutz-Jeghers syndrome, Laugier-Hunziker syndrome or Addison's disease. There were no polyps in a previously performed colonoscopy and no other systemic symptoms. We made the diagnosis Laugier-Hunziker syndrome, a benign skin disorder that doesn't require treatment, confirmed by skin biopsy.

[Sex cord tumors with annular tubules: About 4 cases and literature review]

Sex cord tumor with annular tubules (SCTAT) is a rare ovarian tumor. It belongs to sex cord and stromal tumor of the ovary and represents less than 1% of cases. It includes two forms: the first one associated with Peuz-Jeghers syndrome and the second sporadic. We report 4 cases of SCTAT collected at the department of pathology of Salah Azaiez Institute of Tunis over the 12 last years. The age ranged from 10 to 32 years. Symptoms were non specific except for one case revealed by precocious puberty. One patient had Peutz-Jeghers syndrome associated. Tumors were unilateral. Gross findings showed often a solid tumor with yellow cut surface. Their size ranged from 0.5cm to 28cm. Their morphological features were characteristic. Immunohistochemistry showed that tumor cells expressed inhibin and claretinin. The treatment was surgical, often conservative. The diagnosis of malignancy wasn't focused on histological features, but on tumor extension, clinical course, and presence of metastases. Evolution was often favorable. We also performed a systematic review of the literature that identified 166 cases. Features of these cases were studied. We also compared these features between sporadic and syndromic forms and between benign and malignant forms. In conclusion, SCTAT is a rare tumor, usually benign. Its diagnosis is based on histological examination. There is a malignant potential especially in sporadic forms, estimated at 20%. Treatment is most often conservative, based on oophorectomy.

68 Ga-FAPI-04 Versus 18 F-FDG PET/CT in a Case of Peutz-Jeghers Syndrome

ABSTRACT

Peutz-Jeghers syndrome is a rare inherited hamartomatous polyposis syndrome. We describe 68 Ga-FAPI-04 and 18 F-FDG PET/CT findings in a case of Peutz-Jeghers syndrome with primary duodenal clear cell sarcoma, peritoneal metastases, and multiple intestinal polyps varying in size. The duodenal tumor and its metastases showed increased FDG and FAPI uptake. The peritoneal metastases were delineated more clearly on FAPI PET/CT compared with FDG PET/CT. More interestingly, the intestinal polyps showed increased FDG uptake and no FAPI uptake.

Juvenile polyposis syndrome: An overview

Juvenile polyposis syndrome (JPS) is a rare precancerous condition that confers an increased risk of developing gastrointestinal cancers. The inheritance pattern is autosomal dominant. JPS should be clinically suspected when the other hamartomatous polyposis syndromes are excluded (i.e., Peutz- Jeghers and Cowden), in presence of numerous juvenile polyps in the colorectum or in other GI locations. Among the syndromic features, JPS can present with concomitant extra-intestinal manifestations, above all cutaneous manifestations such as telangiectasia, pigmented nevi, and skeletal stigmata. Pathogenic germline variants of either BMPR1A or SMAD4 cause the syndrome. In JPS a cumulative risk of CRC of 39-68% has been estimated. The oncological risk justifies and imposes prevention strategies that aim at the cancer risk reduction through endoscopic screening, as recommended by international scientific societies. The aim of this review is to summarize clinical and genetic features of JPS and to elucidate the steps of the clinical management from diagnosis to surveillance.

Multidisciplinary management for Peutz-Jeghers syndrome and prevention of vertical transmission to offspring using preimplantation genetic testing

BACKGROUND

Peutz Jeghers syndrome (PJS) is an autosomal dominant genetic disorder caused by STK11 mutation with a predisposition to gastrointestinal polyposis and cancer. PJS patients suffer poor quality of life and are highly concerned about whether deleterious mutations transmit to their offspring. Therefore, this study aimed to propose feasible clinical management and provide effective preimplantation genetic testing for monogenic defect (PGT-M) strategies to protect offspring from inheriting the disease.

METHODS

A hospital-based clinical retrospective analysis reviewing the clinical characteristics and fertility aspects was first conducted on 51 PJS patients at the First Affiliated Hospital of Zhengzhou University between January 2016 and March 2021. Among the 51 patients, the PGT-M strategy was further carried out in 4 couples, which started with a biopsy of the trophectoderm cells of embryos and whole genome amplification using multiple displacement amplification. Thereafter, single nucleotide polymorphism linkage analyses based on karyomapping were performed with copy number variations of the embryos identified simultaneously. Finally, prenatal diagnosis was used to verify the validity of the PGT-M results.

RESULTS

A comprehensive management flowchart adopted by the multidisciplinary team model was formulated mainly focusing on clinical genetic and gastrointestinal aspects. Under the guidelines of this management, 32 embryos from 4 PJS pedigrees were diagnosed and 2 couples successfully conceived healthy babies free of the STK11 pathogenic mutation.

CONCLUSIONS

Our comprehensive management could help affected families avoid having children with PJS through preimplantation genetic testing and provide meaningful guidance for multidisciplinary clinical practice on PJS.

Feminizing Sertoli Cell Tumor Associated with Peutz-Jeghers Syndrome (Histologic and ultrastructural study)

A case of Peutz-Jeghers syndrome associated with Sertoli cell tumor of the testis and bilateral gynecomasty in an 8-year-old boy is described. The authors emphasize the unusual histologic and ultrastructural features of the tumor and discuss the physiopathologic aspects of the present case.

Chemoprevention in Patients with Peutz-Jeghers Syndrome: Lessons Learned

LESSONS LEARNED

Motivating patients to enroll in chemopreventive studies is challenging.Chemoprevention with toxic drugs is not feasible.

BACKGROUND

LKB1 mutations are the underlying genetic abnormality causing Peutz-Jeghers syndrome (PJS) and are a potential target for everolimus. In this phase II study, the efficacy of everolimus on polyp and tumor growth in PJS patients was investigated.

METHODS

Adult patients with a proven LKB1 mutation and who were suitable for everolimus treatment were included in two different PJS cohorts: (a) patients with unresectable malignancies and (b) patients with high-risk polyps. Treatment in both groups was oral everolimus, 10 mg daily. Response rates were primary endpoints for both cohorts.

RESULTS

Between October 2011 and April 2016, only two patients were enrolled, one in each cohort. A 49-year-old patient with advanced pancreatic cancer in cohort 1 was progressive after 2 months. A 52-year-old male patient in cohort 2 experienced severe toxicity and refused treatment after 4 months, even though endoscopy suggested stabilization of polyps. Adverse events included dental inflammations, mucositis, and rash. In 2016, the trial was aborted for lack of accrual, despite extensive accrual efforts in an area where PJS is highly prevalent and care is highly centralized.

CONCLUSION

Due to accrual problems, no conclusions can be drawn about the value of everolimus in PJS treatment, questioning the feasibility of this agent for chemoprevention.

A giant and extensive solitary Peutz-Jeghers-type polyp in the antrum of stomach: Case report

RATIONALE

A solitary Peutz-Jeghers-type polyp is a hamartomatous polyp which without either mucocutaneous pigmentation or a family history of Peutz-Jeghers syndrome (PJS). It can occur in all of the gastrointestinal tract, but it is extremely rare in the stomach.

PATIENT CONCERNS

A 53-year-old man was admitted to the local hospital with left upper abdominal pain lasting 2 weeks. A gastroscopy showed a giant and extensive bulging lesion on the greater curvature and posterior and anterior walls of the gastric antrum, involving three-quarters of the gastric wall. Endoscopic ultrasonography showed a muscularis mucosa lesion.

DIAGNOSES

A solitary Peutz-Jeghers-type polyp in the antrum of stomach.

INTERVENTIONS

The patient underwent an endoscopic submucosal dissection (ESD).

OUTCOMES

The patient recovered quickly, without any complications.

LESSONS

This is the second largest gastric solitary Peutz-Jeghers-polyp reported until now, and the largest gastric solitary Peutz-Jeghers type-polyp treated by endoscope.

Genetic analysis and clinical description of Greek patients with Peutz-Jeghers syndrome: Creation of a National Registry

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant disorder caused by germline mutations in the STK11 tumor suppressor gene. PJS patients face a cumulative cancer risk as high as 93% for all sites combined. The present study reports the spectrum of STK11 mutations in eight families with clinical diagnosis of PJS, summarizes the clinical characteristics of sixteen mutation carriers and launches a National Registry for PJS in Greece. STK11 loss-of-function (LoF) mutations were detected in 87.5% of index patients. Carriers presented with their first manifestation at a median age of 24.9 years, while early-onset breast cancer was the most frequent malignancy observed, highlighting the need for breast surveillance. Out of the deleterious STK11 mutations identified, two were novel: c.375_376delGT and c.676_679dupAACG, with 57.2% of these potentially occurring de novo. Using all available clinical and genetic data, the National Registry for Greek PJS was established in an attempt to better characterize the syndrome and raise awareness among patients and clinicians (available at https://www.peutzjeghersgreece.org). This is the first comprehensive genetic analysis and clinical characterization of Greek PJS patients, where a high incidence of breast cancer was observed and the first attempt to centralize all data in a National Registry.

Peutz-Jeghers syndrome with intermittent upper intestinal obstruction: A case report and review of the literature

RATIONALE

Peutz-Jeghers syndrome (PJS) is an autosomal dominant genetic syndrome characterized by a unique type of gastrointestinal hamartomatous polyp associated with oral and anal mucocutaneous pigmentations. Peutz-Jeghers polyps occur most numerously in the small intestine but frequently in the colon and stomach, only a few cases have been reported in the duodenum.

PATIENT CONCERN

A further family history survey discovered 10 out of 14 members of the family (in 4 generations) had mucocutaneous pigmentations, but many of them were living in rural areas where they had no access to specialized medical services, so none were checked with endoscopy for polyps of hamartoma.

DIAGNOSES

We report the case of a boy patient with mucocutaneous pigmentations over the lips, and a history of recurrent bouts of vomit and anemia over the preceding two years, no abdominal pain and mass. An upper gastrointestinal endoscopy revealed some small polyps in the stomach and multiple sessile polyps in the second part of the duodenum, but colonoscopy exam did not reveal any lesion.

INTERVENTIONS

A double polypectomy and duodenum segmentary resection with end-to-end anastomosis was performed. Histopathology of the resected duodenum polyps indicated it to be a typical hamartomatous polyp.

OUTCOMES

The child was under regular follow-up and recovered well.

LESSONS

In this case, the patient was characteristic with pigmentations on his lips and intermittent upper intestinal obstruction (due to mass duodenal polyps), there are no definitive guidelines for the treatment to duodenal PJS hamartomatous polyp, each case requires tailor-made management.

Laparoscopic restorative proctocolectomy with ileal pouch-anal anastomosis for Peutz-Jeghers syndrome with synchronous rectal cancer

We report on a patient diagnosed with Peutz-Jeghers syndrome (PJS) with synchronous rectal cancer who was treated with laparoscopic restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA). PJS is an autosomal dominant syndrome characterized by multiple hamartomatous polyps in the gastrointestinal tract, mucocutaneous pigmentation, and increased risks of gastrointestinal and nongastrointestinal cancer. This report presents a patient with a 20-year history of intermittent bloody stool, mucocutaneous pigmentation and a family history of PJS, which together led to a diagnosis of PJS. Moreover, colonoscopy and biopsy revealed the presence of multiple serried giant pedunculated polyps and rectal adenocarcinoma. Currently, few options exist for the therapeutic management of PJS with synchronous rectal cancer. For this case, we adopted an unconventional surgical strategy and ultimately performed laparoscopic restorative proctocolectomy with IPAA. This procedure is widely considered to be the first-line treatment option for patients with ulcerative colitis or familial adenomatous polyposis. However, there are no previous reports of treating PJS patients with laparoscopic IPAA. Since the operation, the patient has experienced no further episodes of gastrointestinal bleeding and has demonstrated satisfactory bowel control. Laparoscopic restorative proctocolectomy with IPAA may be a safe and effective treatment for patients with PJS with synchronous rectal cancer.

Peutz-Jeghers Syndrome: Pathobiology, Pathologic Manifestations, and Suggestions for Recommending Genetic Testing in Pathology Reports

Peutz-Jeghers syndrome (PJS), in most cases, is attributed to mutation in STK11/LKB1 and is clinically characterized by gastrointestinal hamartomatous polyposis, mucocutaneous pigmentation, and predisposition to certain neoplasms. There are currently no recommended gynecologic screening or clinical surveillance guidelines beyond those recommended for the general population; however, cervical cytology samples must be examined with a high level of suspicion for cervical adenocarcinoma. It is considered prudent to note the established association with PJS and recommend referral for genetic counseling. Complete surgical excision after a diagnosis of atypical lobular endocervical glandular hyperplasia is recommended.

Clinical features, endoscopic polypectomy and STK11 gene mutation in a nine-month-old Peutz-Jeghers syndrome Chinese infant

AIM: To investigate multiple polyps in a Chinese Peutz-Jeghers syndrome (PJS) infant.

METHODS: A nine-month-old PJS infant was admitted to our hospital for recurrent prolapsed rectal polyps for one month. The clinical characteristics, a colonoscopic image, the pathological characteristics of the polyps and X-ray images of the intestinal perforation were obtained. Serine threonine-protein kinase 11 (STK11) gene analysis was also performed using a DNA sample from this infant.

RESULTS: Here we describe the youngest known Chinese infant with PJS. Five polyps, including a giant polyp of approximately 4 cm × 2 cm in size, were removed from the infant’s intestine. Laparotomy was performed to repair a perforation caused by pneumoperitoneum. The pathological results showed that this child had PJS. Molecular analysis of the STK11 gene further revealed a novel frameshift mutation (c.64_65het_delAT) in exon 1 in this PJS infant.

CONCLUSION: The appropriate treatment method for multiple polyps in an infant must be carefully considered. Our results also show that the STK11 gene mutation is the primary cause of PJS.

Energy sensing and cancer: LKB1 function and lessons learnt from Peutz-Jeghers syndrome

We describe in this review increasing evidence that loss of LKB1 kinase in Peutz-Jeghers syndrome (PJS) derails the existing natural balance between cell survival and tumour growth suppression. LKB1 deletion can plunge cells into an energy/oxidative stress-induced crisis which leads to the activation of alternative and often carcinogenic pathways to maintain cellular energy levels. It therefore appears that although LKB1 deficiency can suppress oncogenic transformation in the short term, it can ultimately lead to more progressed and malignant phenotypes by driving abnormal cell differentiation, genomic instability and increased tumour heterogeneity.

Clinical and molecular features of young-onset colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer related mortality worldwide. Although young-onset CRC raises the possibility of a hereditary component, hereditary CRC syndromes only explain a minority of young-onset CRC cases. There is evidence to suggest that young-onset CRC have a different molecular profile than late-onset CRC. While the pathogenesis of young-onset CRC is well characterized in individuals with an inherited CRC syndrome, knowledge regarding the molecular features of sporadic young-onset CRC is limited. Understanding the molecular mechanisms of young-onset CRC can help us tailor specific screening and management strategies. While the incidence of late-onset CRC has been decreasing, mainly attributed to an increase in CRC screening, the incidence of young-onset CRC is increasing. Differences in the molecular biology of these tumors and low suspicion of CRC in young symptomatic individuals, may be possible explanations. Currently there is no evidence that supports that screening of average risk individuals less than 50 years of age will translate into early detection or increased survival. However, increasing understanding of the underlying molecular mechanisms of young-onset CRC could help us tailor specific screening and management strategies. The purpose of this review is to evaluate the current knowledge about young-onset CRC, its clinicopathologic features, and the newly recognized molecular alterations involved in tumor progression.

[Pilot clinical and genetic study of Russian patients with Peutz-Jeghers syndrome]

Peutz-Jeghers syndrome is a rare hereditary syndrome characterized by presence of hamartoma polyps in intestinal tract and usually by mucocutaneous pigmentation. Clinical-genetic characteristics of Russian patients with Peutz-Jeghers syndrome were studied for the first time. Four germline mutations in STK11gene were found in probands from six families and three of them had not been described previously. Clinical pattern of disease in Russian patients included: frequent polyposis of colon and stomach (62,5% and 75%, respectively) along with small bowel; frequent presence of malignant tumors (62,5%). These clinical aspects can help physicians to find out Peutz-Jeghers syndrome. Molecular-genetic testing of individuals should be recommended.

Endoscopic snare papillectomy for a solitary Peutz-Jeghers-type polyp in the duodenum with ingrowth into the common bile duct: Case report

Solitary duodenal Peutz-Jeghers (PJ)-type hamartomatous polyps are rare and considered a different disease entity than classic PJ syndrome. We describe the case of an 89-year-old man admitted to our emergency department with symptoms of acute cholangitis, liver dysfunction, and slight jaundice. Magnetic resonance imaging showed multiple signal voids, reflecting choledocholithiasis, and an oval-shaped tumor in the common bile duct (CBD). Following endoscopic retrograde cholangiopancreatography, the patient was diagnosed with a lower CBD tumor 20 mm in diameter. Endoscopic sphincterotomy was performed for choledocholithotomy, resulting in the expulsion of a large tumor with a stalk connected to the papilla of Vater. The tumor was successfully excised en bloc by endoscopic snare papillectomy. Histopathologic examination showed that the tumor was a PJ-type hamartomatous polyp. No mucocutaneous pigmentation of the skin was evident and the patient’s family history was negative. Solitary duodenal PJ-type hamartomatous polyps are usually diagnosed incidentally during endoscopy for other indications because most of these tumors are asymptomatic or have nonspecific presentations. To our knowledge, this is the first reported solitary PJ-type polyp with intra-CBD growth treated by endoscopic snare papillectomy.

A case of Peutz-Jeghers syndrome associated with high-grade intramucosal neoplasia

Peutz-Jeghers syndrome (PJS) is a rare, inherited autosomal dominant disease characterized by mucocutaneous pigmentation and polyps in the gastrointestinal tract. Here, we report the rare case of a 64-year-old female patient with pigmentation on her lips and extremities for over 63 years and intermittent abdominal pain and, diarrhea for 3 years. The presence of intestinal and colorectal hamartomatous polyps was confirmed. The removal and characterization of her rectal polyp showed it to be a typical hamartomatous polyp with a portion of it being an adenoma with high-grade intramucosal neoplasia. A survey of the patient's family identified 9 people in the family with Peutz-Jeghers syndrome and three of them have already died from colorectal cancer. This case study serves as an example of how imperative it is to survey the patient about their family history in order to detect early cancerous lesions.

Update on imaging of Peutz-Jeghers syndrome

Peutz-Jeghers syndrome (PJS) is a rare, autosomal dominant disease linked to a mutation of the STK 11 gene and is characterized by the development of benign hamartomatous polyps in the gastrointestinal tract in association with a hyperpigmentation on the lips and oral mucosa. Patients affected by PJS have an increased risk of developing gastrointestinal and extra-digestive cancer. Malignancy most commonly occurs in the small-bowel. Extra-intestinal malignancies are mostly breast cancer and gynecological tumors or, to a lesser extent, pancreatic cancer. These polyps are also at risk of acute gastrointestinal bleeding, intussusception and bowel obstruction. Recent guidelines recommend regular small-bowel surveillance to reduce these risks associated with PJS. Small-bowel surveillance allows for the detection of large polyps and the further referral of selected PJS patients for endoscopic enteroscopy or surgery. Video capsule endoscopy, double balloon pushed enteroscopy, multidetector computed tomography and magnetic resonance enteroclysis or enterography, all of which are relatively new techniques, have an important role in the management of patients suffering from PJS. This review illustrates the pathological, clinical and imaging features of small-bowel abnormalities as well as the role and performance of the most recent imaging modalities for the detection and follow-up of PJS patients.

Multiple genital tract tumors and mucinous adenocarcinoma of colon in a woman with Peutz-Jeghers syndrome: a case report and review of literatures

We report a very rare case of Peutz-Jeghers syndrome (PJS) composed of multiple genital tract tumors and mucinous adenocarcinoma. A 46-year-old woman presented to our hospital with lower abdominal pain resulting from PJS involves sex cord tumor with annular tubules (SCTAT), ovarian mucinous tumor, ovarian serous tumor, mucinous adenocarcinoma of colon. The CEA concentration is high before surgery, and decreases after the surgery and subsequent chemoradiotherapy. This case demonstrates a classic clinical presentation of a patient with PJS. PJS patients have increased risk of malignancy and early detection and regular surveillance of the high-risk patients with PJS is crucial. Surgery may be required for obstructive gastrointestinal lesions as well as those exhibiting malignant degeneration.

Solitary Peutz-Jeghers-type appendiceal hamartomatous polyp growing into the terminal ileum

Solitary Peutz-Jeghers type hamartomatous polyp is rare. It is considered to be related to a variant Peutz-Jeghers syndrome (PJS) and may be a separate disease entity. A 50-year-old man was referred to our hospital with a diagnosis of intussusception in the terminal ileum and underwent segmental ileal resection with appendectomy. We identified a 3.5-cm diameter polyp arising from the appendix with ingrowth into the terminal ileum. The polyp was confirmed to be a hamartomatous polyp of Peutz-Jeghers-type, histologically. However, the patient had no characteristic manifestations of PJS such as mucocutaneous pigmentation and family history. There are few reports of appendiceal hamartomatous polyp in PJS patients and solitary appendiceal hamartomatous polyp is even rarer. Also, rather than telescoping, ours is the first reported intussuscepted lesion, to the best of our knowledge.

Peutz-Jeghers syndrome--a rare case and a literature review

The Peutz-Jeghers syndrome is inherited condition, characterized by hamartomatous gastrointestinal polyposis and with mucocutaneous pigmentation. We have experienced a case with typical clinical features, diagnosed before complication's development. In order to prevent cancer setting it is recommended to perform aggressive screening and high-technological procedures.

Overexpression of aromatase associated with loss of heterozygosity of the STK11 gene accounts for prepubertal gynecomastia in boys with Peutz-Jeghers syndrome

CONTEXT

Peutz-Jeghers syndrome (PJS) is an autosomal-dominant disorder that arises as a consequence of mutations in the STK11 gene that encodes LKB1. PJS males often have estrogen excess manifesting as gynecomastia and advanced bone age. We and others have previously described an increase in testicular aromatase expression in PJS patients. However, the underlying mechanism has not yet been explored.

OBJECTIVE

The aim of this study was to characterize the role of LKB1 in regulating the expression of aromatase in boys with PJS via signaling pathways involving AMP-activated protein kinase (AMPK) and cyclic AMP-responsive element binding protein-regulated transcription coactivators (CRTCs).

PATIENTS

We studied testicular biopsies from two boys with STK11 mutations: a 13-year-old boy and an unrelated 4-year-old boy with prepubertal gynecomastia and advanced bone age, as well as breast tissue from the 13-year-old boy.

RESULTS

Loss of heterozygosity of STK11, measured by the absence of LKB1 immunofluorescence, was observed in Sertoli cells of abnormal cords of testis samples from affected individuals. This was associated with loss of p21 expression and decreased phosphorylation of AMPK, known downstream targets of LKB1, as well as the increased expression of aromatase. Similar results of low LKB1 expression in cells expressing aromatase were observed in the mammary epithelium from one of these individuals. Nuclear expression of the CRTC proteins, potent stimulators of aromatase and known to be inhibited by AMPK, was significantly correlated with aromatase.

CONCLUSIONS

Loss of heterozygosity of the STK11 gene leads to an increase in aromatase expression associated with an increase in CRTC nuclear localization, thereby providing a mechanism whereby PJS results in increased endogenous estrogens in affected males.

Unusually early presentation of small-bowel adenocarcinoma in a patient with Peutz-Jeghers syndrome

Peutz-Jeghers syndrome (PJS) is an autosomal dominant cancer predisposition syndrome characterized by melanotic macules and hamartomatous polyps. Small-bowel surveillance in the pediatric PJS population is not designed to identify small-bowel malignancy, which is thought to arise in adulthood. A 13-year-old boy presented with lead-point intussusception, requiring emergent surgical resection. A mucinous adenocarcinoma was found arising from high-grade dysplasia within a polyp. On the basis of these findings and mucosal pigmentation, he was diagnosed with PJS. DNA sequencing revealed a heterozygous c.921-1G>T STK11 mutation. This case is the earliest onset of small-bowel carcinoma in PJS, an observation relevant to surveillance guidelines.

Peutz-Jeghers syndrome and family survey: a case report

Peutz-Jeghers syndrome (PJS) is a rare inherited autosomal dominant disease characterized by mucocutaneous pigmentation and multiple polyps in the gastrointestinal tract. We report on an 18-year-old Chinese male who complained with pigmentation on face and extremities for over 10 years. Colonoscopy revealed more than ten polyps from transverse colon to rectum. The family survey included 15 family members from three generations, and 6 PJSs (4 males and 2 females) were found. This case is reported because of its rarity of Peutz-Jeghers syndrome and the survey of family history.

[Clinical characteristics and mutation analysis of the LKB1 gene in a Peutz-Jeghers syndrome pedigree]

OBJECTIVE

To investigate clinical characteristics and mutation of the LKB1 gene in a Peutz-Jeghers syndrome (PJS) pedigree.

METHOD

Clinical data of a PJS family were analyzed and LKB1 gene mutation was detected by systematic screening with multiplex ligation-dependent probe amplification (MLPA) and DNA sequencing. Meanwhile, two hundred and fifty healthy adults were enrolled in this study and denaturing high performance liquid chromatography (PCR-DHPLC) was carried out to verify the mutation excluding polymorphism sites found in this family. Changes in protein structure and function caused by the mutated coding sequence was analyzed by SWISS-MODEL software.

RESULT

The proband had pigmented mucocutaneous lesions and multiple hamartomatous polyps in the gastrointestinal tract. There was no fragment deletion of LKB1 gene detected by MLPA. Among PJS family and 250 healthy adults, germline mutation c. 924G > C of LKB1 which cause Trp308Cys in protein sequence was identified only in the proband and another affected member. LKB1 protein activity could be reduced due to changes in LKB1 protein conformation structure by Trp308Cys.

CONCLUSION

Peutz-Jeghers syndrome (PJS) is an autosomal dominant disorder characterised by mucocutaneous pigmentation, multiple gastrointestinal hamartomatous polyps and heredofamilial nature. Gene identification and mutagen screening of LKB1 gene in all PJS patients and first degree relatives will contribute to a definite diagnosis and improve the life span of the family.

A rationale for mTOR inhibitors as chemoprevention agents in Peutz-Jeghers syndrome

Peutz-Jeghers patients frequently develop clinically significant complications, namely hemorrhage and bowel obstruction, from small intestinal hamartomatous polyps that frequently require surgery. In addition, many PJS patients develop epithelial malignancies in a variety of organs. The vast majority of PJS is due to germline alterations in the STK11 gene that encodes a protein that modulates PI3-kinase signaling, a key regulator of cell survival and growth. One of the major downstream mediators of PI3-kinase signaling is mTOR, the mammalian target of rapamycin. Several drugs that inhibit the PI3-kinase signal transduction pathway are in development and one, RAD001 (everolimus), an mTOR inhibitor, was recently approved for the treatment of renal cell carcinoma. Effective chemoprevention of intestinal polyps would be a first step in simplifying and improving the management of PJS patients. We present here, the rationale for the first human PJS chemoprevention trial using an mTOR inhibitor.

Papillary thyroid carcinoma in Peutz-Jeghers syndrome

BACKGROUND

Peutz-Jeghers syndrome (PJS) is a rare dominantly inherited disease characterized by the association of gastrointestinal hamartomatous polyposis, mucocutaneous hyperpigmentation, and increased risk of cancer at different target organs. Its occurrence with differentiated thyroid cancer, particularly papillary thyroid carcinoma (PTC), even if rare, has been described.

SUMMARY

We here present a case of PTC observed in a PJS patient and a review of the literature aiming at discussing the utility of thyroid surveillance in the management of these patients. A 22-year-old woman presenting with hyperpigmented lesions of the lips and hamartomatous polyps in the stomach, duodenum, jejunum, and ileum, leading to the suspicion of PJS, was submitted to genetic analysis. Mutation scanning of the Liver Kinase B1 (LKB1) gene identified the presence of the truncating mutation E265X, thus confirming the clinical diagnosis. Beside the endoscopic, radiologic, and echographic evaluations required by the standard surveillance guidelines, the patient had a neck ultrasound (US), which showed a 5×4×6 mm hypoechoic nodule in the right thyroid lobe. The nodule contained microcalcifications and a perinodular vascular pattern. The cytological preparations derived from US-guided fine-needle aspiration biopsy of the nodule demonstrated the presence of PTC. The patient underwent a video-assisted total thyroidectomy and the histological examination revealed a follicular variant of papillary microcarcinoma. Radioactive iodine therapy was not performed because of the small size of the lesion. The patient was started on levothyroxine therapy to keep the serum thyrotropin levels suppressed. Both the sequencing and the multiplex ligation-dependent probe amplification analysis could not identify any LKB1 mutation in the tumor specimen, and the methylation-specific polymerase chain reaction assay excluded hypermethylation of the LKB1 promoter as the mechanism of inactivation for the remaining normal allele in the tumor.

CONCLUSIONS

Although other mechanisms of LKB1 silencing may be responsible for its inactivation in the thyroid cancer, we cannot rule out that the occurrence of thyroid carcinoma could be a coincidental finding in this patient. However, the case here presented suggests that US of the thyroid could possibly become an integral part of the evaluation and the follow-up program adopted for PJS patients.

[Gastrointestinal bleeding and intussusception caused by Peutz-Jeghers syndrome]

Peutz-Jeghers syndrome (PJS) is an inherited, autosomal dominant disorder characterised by haematomatous polyps in the gastrointestinal tract and mucocutaneus hyperpigmentation. A girl 15 years of age presented with microcytic, hypochrome anaemia. Endoscopy revealed several polyps in the stomach and colon. The patient was later operated due to an intussusception from polyps in the jejunum. Histology proved the polyps to be haematomatous as seen in PJS. Patients with PJS have an increased risk of developing both gastrointestinal and extra-gastrointestinal cancers. Screening recommendation for PJS is outlined.

[Guidelines for diagnosis, treatment, surveillance and prevention of cancer in patients with familial non-adenomatous polyposis]

Approximately 30% of colorectal cancers exhibit familial clustering. Currently, we recognize a number of different types of polyps and polyposis syndromes that are classified according to the histology of the typical polyp. We differentiate between adenomas, hyperplastic, and hamartomatous polyps as well as between syndromes that are manifested by 10-100 or above 100 polyps. It is essential to distinguish between these syndromes as each has a different mode of presentation, spectrum of signs and symptoms and cancer risk associated with them. With the knowledge accumulating, we now have the tools to lower the risk of cancer by performing specific screening programs that are tailored to each syndrome. In these guidelines we focus on the non-adenomatous polyps, hyperplastic and hamartomatous polyposis syndromes. We outline the importance of multi-sector team work that includes the family practitioner, gastroenterologist, pathologist, genetic counselor, surgeon, and social worker.

Endometrial carcinoma and ovarian sex cord tumor with annular tubules in a patient with history of Peutz-Jeghers syndrome and multiple malignancies

Peutz-Jeghers syndrome is a rare syndrome which is inherited in a dominant manner. It is characterized by hamartomatous polyps of the gastrointestinal tract, hyperpigmented macules of the oral mucosa and an increased risk of developing neoplasms in the gastrointestinal tract, pancreas, breast and genital system. Women with Peutz-Jeughers syndrome often develop an ovarian sex cord tumor and cervical adenocarcinoma of minimal deviation adenoma malignum type. A case of a 58-year-old patient with Peutz-Jeghers syndrome and history of multiple malignancies (thyroid, breast and colon cancer) who presented with metrorrhagia is reported. The dilatation and curettage revealed endometrial adenocarcinoma. The patient underwent total abdominal hysterectomy with bilateral oophorectomy. The histologic examination showed an endometrioid endometrial adenocarcinoma that developed in atypical endometrial hyperplasia. The histologic examination of the right ovary revealed a sex cord tumor with annular tubules, measuring 3 cm. Sex cord tumors with annular tubules in patients with Peutz-Jeghers syndrome are usually small, bilateral tumors of the ovaries which have common characteristics with granulosa cell tumor and Sertoli cell tumor. Hyperestrogenism is a rather common finding with development of estrogen-dependent lesions.

Female genital tract tumors and gastrointestinal lesions in the Peutz-Jeghers syndrome

BACKGROUND

Peutz-Jeghers Syndrome (PJS) is a rare genetic disorder characterized by mucocutaneous melanin deposition, and intestinal hamartomatous polyps, with an increased risk of breast, gastrointestinal, and female genital tract cancers.

CASE REPORT

Multiple genital tract neoplasms in a 52-year-old northern Thai woman with PJS are described. The patient presented with abdominal distention. A pelvic ultrasound scan showed a left adnexal mass, diagnosed as mucinous cyst. An ovarian microscopic cystadenoma was diagnosed together with a minimal deviation mucinous adenocarcinoma (MDA) of the uterine cervix and mucinous metaplasia in tubal mucosa and endometrium. Pathological findings warranted a search for evidence of PJS Typical pigmentation at the hard palate and colonoscopic finding of hamartomatous polyps established the diagnosis of PJS. At four-year follow-up, the patient still showed no evidence of tumor recurrence.

CONCLUSION

A case of PJS complicated by multiple and contemporaneous genital tract tumors with rare histological findings is presented. The presented case suggests MDA and mucinous metaplasia warrant a search for PJS.

[Expression and significance of interferon-inducible transmembrane protein-1 gene in Peutz-Jeghers syndrome]

OBJECTIVE

To detect the mRNA and protein expression of interferon-inducible transmembrane protein-1 (IFITM1) in Peutz-Jeghers syndrome (PJS) and investigate the role of IFITM1 in the occurrence, development and carcinogenesis of PJS polyps.

METHODS

Reverse transcription-PCR was employed to detect the mRNA expression of IFITM1 in 16 PJS polyp samples, adenomatous polyp tissues, colon adenocarcinoma samples, and normal intestinal mucosal tissues. The protein expression and localization of IFITM1 in these tissues (32 cases for each) were detected with immunohistochemical (IHC) staining.

RESULTS

The IFITM1 mRNA expression was detected in all these tissues, and the expression intensity increased in the order of normal intestinal mucosa, PJS polyp, adenomatous polyp, and colon adenocarcinoma (F=92.704, P=0.000). IHC revealed that IFITM1 protein was localized mainly on the cell membrane and in the cytoplasm, with increased expression intensity in the same order as its mRNA and showing significant differences between the tissues by several rank-sum test (Kruskal-Wallis H, chi(2)=37.036, p=0.000).

CONCLUSION

The expression level of IFITM1 is associated with the progression of the carcinogenetic process in PJS polyp, and can be used as a sensitive biomarker for diagnosis and prognostic evaluation of PJS.

Chemopreventive efficacy of rapamycin on Peutz-Jeghers syndrome in a mouse model

Germline mutations in LKB1 cause Peutz-Jeghers syndrome (PJS), an autosomal dominant disorder with a predisposition to gastrointestinal polyposis and cancer. Hyperactivation of mTOR-signaling has been associated with PJS. We previously reported that rapamycin treatment of Lkb1(+/-) mice after the onset of polyposis reduced the polyp burden. Here we evaluated the preventive efficacy of rapamycin on Peutz-Jeghers polyposis. We found that rapamycin treatment of Lkb1(+/-) mice initiated before the onset of polyposis in Lkb1(+/-) mice led to a dramatic reduction in both polyp burden and polyp size and this reduction was associated with decreased phosphorylation levels of S6 and 4EBP1. Together, these findings support the use of rapamycin as an option for chemoprevention and treatment of PJS.

Molecular insights into Peutz-Jeghers syndrome: two probands with a germline mutation of LKB1

LKB1 encodes a serine/threonine protein kinase that is defective in patients with Peutz-Jeghers syndrome (PJS), a hereditary disorder characterized by gastrointestinal hamartomatous polyposis and an increased risk of cancer development. Although a tentative molecular classification of PJS patients was recently made according to their LKB1 mutation status, it is difficult to clarify the genotype-phenotype relationship because of the rarity and genetic heterogeneity of this disease. Here we report on two probands with PJS whose intestinal hamartomatous polyposis was treated by laparoscopyassisted polypectomy. Direct sequencing analyses revealed a nonsense mutation at codon 240 in exon 5 in one patient, and a mutation at a splicing donor site in intron 5 in the other patient. No additional somatic mutations were detected in the resected hamartomas in either case. Immunohistochemical analysis revealed an elevated expression of cyclooxygenase-2, and almost complete loss of LKB1 expression in the polyps, suggesting that a biallelic inactivation of the LKB1 gene was responsible for the hamartoma formation. Methylation-specific polymerase chain reaction analysis revealed no hypermethylation of the LKB1 promoter. Mutation analysis is useful in making a precise diagnosis of PJS in candidate probands, and may in the near future provide valuable information for predicting cancer risk based on genotype-phenotype correlations.

Bone morphogenetic protein signalling in colorectal cancer

Much of the current understanding of colorectal cancer stems from the study of rare, inherited colorectal cancer syndromes. Mutations in the bone morphogenetic protein (BMP) pathway have been found in juvenile polyposis, an inherited polyposis syndrome that predisposes to colorectal cancer. The hamartomas that develop in these patients and in BMP pathway mutant mice have a remarkable mesenchymal component. Further evidence in mice suggests a primary role for mesenchymal loss of BMP signalling in hamartoma development. Here, we examine this evidence and question its relevance to sporadic colorectal carcinogenesis.