Duodenal cancer in a young patient with Peuts-Jeghers syndrome harboring an entire deletion of the STK11 gene

A 21-year-old woman with Peuts-Jeghers syndrome (PJS) was referred to our hospital for gastrointestinal surveillance. She had been diagnosed as having PJS from a young age based on her family history and the presence of mucocutaneous pigmentation on her lips and oral mucosa. Her mother and brother had PJS harboring an entire deletion of the STK11 gene. She had tetralogy of Fallot, atrial tachycardia, sick sinus syndrome, and mental retardation in her past history. Esophagogastroduodenoscopy identified a protruded lesion with a depressed area that occupied the lumen half-circumferentially in the duodenal second portion and also showed a 10-mm protruded lesion on the anterior wall of the lower gastric body. Colonoscopy revealed a 3-mm protruded lesion on the rectum. No polyp was found in a barium small bowel series. Biopsies were taken from the duodenal tumor and gastric and colon polyps. Histopathologically, the duodenal tumor revealed a well-differentiated tubular adenocarcinoma, whereas gastric and colon polyps showed hamartomatous polyp. Therefore, subtotal stomach-preserving pancreatoduodenectomy was performed, and subsequent histopathological examination revealed that the duodenal tumor consisted of hamartomatous polyp and a well-differentiated tubular adenocarcinoma with invasion to the muscularis propria. Immunohistochemistry revealed accumulation of nuclear p53 protein, but no accumulation of nuclear β-catenin protein. No RAS mutation was detected. Furthermore, direct sequencing of the STK11 gene in genomic DNA from peripheral blood mononuclear cells did not detect any mutation initially. However, multiplex ligation-dependent probe amplification (MLPA) analysis revealed entire deletion of STK11. These findings suggest that entire deletion of the STK11 gene caused hamartomatous polyps in the entire gastrointestinal tract and, subsequently, duodenal polyps likely gave rise to cancer through p53 mutation.     

A solitary Peutz-Jeghers-type hamartomatous polyp in the duodenum. A case report including results of mutation analysis

BACKGROUND/AIMS: We report a case of solitary Peutz-Jeghers-type hamartomatous polyp of the duodenum in a 22-year-old Japanese woman along with the results of genomic analysis. METHODS/RESULTS: The patient was almost asymptomatic, though endoscopic examination revealed a solitary lobular polypoid lesion measuring 3 cm in diameter in the first portion of the duodenum. The lesion was resected endoscopically. Histopathological examination showed hyperplasia with a tree branch-like extension of the lamina propria derived from the muscularis mucosae, consistent with histological features of polyps of Peutz-Jeghers syndrome (PJS). No mucocutaneous pigmentation of the skin was evident and family history was negative. Analysis of the loss of heterozygosity at the locus of 19p 13.3 and mutation analysis of the STK11/LKB1 gene, which has recently been recognized as a susceptible gene in PJS, were performed. However, no evidence of genomic abnormality was found. CONCLUSION: The clinical and investigative findings in our case suggest that the solitary Peutz- Jeghers-type hamartomatous polyp can be regarded as a clinical entity separate from PJS.     

Molecular and Clinical Characteristics in 46 Families Affected with Peutz–Jeghers Syndrome

Germline mutations of the tumor suppressor gene LKB1/STK11 are responsible for the Peutz–Jeghers syndrome (PJS), an autosomal-dominant disorder characterized by mucocutaneous pigmentation, hamartomatous polyps, and an increased risk of associated malignancies. In this study, we assessed the presence of pathogenic mutations in the LKB1/STK11 gene in 46 unrelated PJS families, and also carried genotype–phenotype correlation in regard of the development of cancer in 170 PJS patients belonging to these families. All LKB1/STK11 variants detected with single-strand conformational polymorphism were confirmed by direct sequencing, and those without LKB1/STK11 mutation were further submitted to Southern blot analysis for detection of deletions/rearrangements. Statistical analysis for genotype–phenotype correlation was performed. In 59% (27/46) of unrelated PJS cases, pathogenic mutations in the LKB1/STK11 gene, including 9 novel mutations, were identified. The new mutations were 2 splice site deletion–insertions, 2 missenses, 1 nonsense, and 4 abnormal splice sites. Genotype–phenotype analysis did not yield any significant differences between patients carrying mutations in LKB1/STK11 versus those without mutations, even with respect to primary biliary adenocarcinoma. This study presents the molecular characterization and cancer occurrence of a large cohort of PJS patients, increases the mutational spectrum of LKB1/STK11 allelic variants worldwide, and provides a new insight useful for clinical diagnosis and genetic counseling of PJS families.     

Peutz-Jeghers综合征的诊治进展和预防性治疗

Peutz-Jeghers综合征(Peutz-Jeghers syndrome,PJS)以皮肤黏膜色素斑、胃肠道错构瘤息肉和遗传性为临床特征.PJS胃肠道息肉可产生梗阻、出血、套叠、恶变等严重并发症,目前其临床治疗以手术和内镜治疗为主,其中双气囊电子小肠镜对于PJS胃肠道息肉的诊断和治疗具有重要的临床意义.随着转化医学...     

Mutation analysis of related genes in hamartoma polyp tissue of Peutz-Jeghers syndrome

BACKGROUND Peutz-Jeghers syndrome(PJS) is a rare disease with clinical manifestations of pigmented spots on the lips, mucous membranes and extremities, scattered gastrointestinal polyps, and susceptibility to tumors. The clinical heterogeneity of PJS is obvious, and the relationship between clinical phenotype and genotype is still unclear.AIM To investigate the mutation status of hereditary colorectal tumor-associated genes in hamartoma polyp tissue of PJS patients and discuss its relationship with the clinicopathological data of PJS.METHODS Twenty patients with PJS were randomly selected for this study and were treated in the Air Force Medical Center(former Air Force General Hospital) PLA between 2008 and 2017. Their hamartoma polyp tissues were used for APC,AXIN2, BMPR1A, EPCAM, MLH1, MLH3, MSH2, MSH6, MUTYH, PMS1, PMS2,PTEN, SMAD4, and LKB1/STK11 gene sequencing using next-generation sequencing technology. The correlations between the sequencing results and clinical pathological data of PJS were analyzed.RESULTS Fourteen types of LKB1/STK11 mutations were detected in 16 cases(80.0%), of which 8 new mutations were found(3 types of frameshift deletion mutations:c.243 del G, c.363_364 del GA, and c.722 del C; 2 types of frameshift insertions: c.144_145 ins GCAAG, and c.454_455 ins C; 3 types of splice site mutations:c.464+1 GT, c.464+1 GA, and c.598-1 GA); 9 cases(45.0%) were found to have 18 types of heterozygous mutations in the remaining 13 genes except LKB1/STK11. Of these, MSH2: c.792+1GA, MSH6: c.3689CG,c.4001+13CCTTAC, PMS1: c.46Ct, and c.922GA were new mutations.CONCLUSION The genetic mutations in hamartoma polyp tissue of PJS are complex and diverse.Moreover, other gene mutations in PJS hamartoma polyp tissue were observed,with the exception of LKB1/STK11 gene, especially the DNA mismatch repair gene(MMR). Colorectal hamartoma polyps with LKB1/STK11 mutations were larger in diameter than those with other gene mutations.     

Molecular insights into Peutz-Jeghers syndrome: two probands with a germline mutation of <Emphasis Type="Italic">LKB1</Emphasis>

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.     

Peutz-Jeghers综合征预防性治疗的研究

Peutz-Jeghers综合征(PJS)又称黑斑息肉病,以皮肤黏膜色素斑、消化道错构瘤息肉和遗传性为临床特征。PJS消化道息肉可产生梗阻、出血、套叠、恶变等严重并发症;目前其临床治疗以手术和内镜治疗为主,都是局部、被动的治疗手段,而无法达到预防息肉发生发展的作用。随着针对PJS的转化医学的进步,针对细胞信号通路及其关键酶的分子靶向药物使PJS消化道息肉的预防性治疗成为可能,其代表是环氧合酶-2的选择性抑制剂和哺乳动物雷帕霉素靶蛋白抑制剂。而以"济生乌梅丸"为代表的中药也为PJS息肉的预防性治疗提供另一个选择。本文总结近年来国内外学者在PJS研究中所取得的共识与进展的基础上,结合自身临床诊治经验,提出了中西医结合预防性治疗PJS胃肠道息肉的思路和方法。以提高临床医生对PJS胃肠道息肉的诊治能力,从而使PJS患者能得到最大的临床获益。     

Peutz-Jeghers' syndrome with malignant development in a hamartomatous polyp: report of one case and review of the literature

The malignant potential of hamartomatous polyps in Peutz-Jeghers' (PPJ) syndrome has been debated. Although it is a very rare event, these polyps can become malignant, as demonstrated by this report. One case of colonic adenocarcinoma associated with Peutz-Jeghers' syndrome is described in a 62-year-old woman. The patient had colonic carcinoma which developed in a hamartomatous polyp. The malignant development of this colonic hamartomatous polyp arising in Peutz-Jeghers' syndrome was pathologically confirmed at surgery. This case also shows a sequence of hamartoma-dysplasia-carcinoma in a hamartomatous polyp without adenomatous changes. This suggests that hamartomatous polyps in Peutz-Jeghers' syndrome may develop into adenocarcinoma and may be a precursor of gastrointestinal carcinomas. STK 11 is a tumor suppressor gene regulating the development of hamartomas, and this somatic mutation promotes gastrointestinal cancer at later stages in Peutz-Jeghers' syndrome.     

Role of Lkb1, the causative gene of Peutz-Jegher's syndrome,in embryogenesis and polyposis

Peutz-Jeghers syndrome (PJS) is a dominantly inherited human disorder characterized by gastrointestinal hamartomatous polyposis and mucocutaneous melanin pigmentation. LKB1 (STK11) serine/threonine kinase is the product of the causative gene of PJS, which has been mapped to chromosome 19p13.3. However, several studies have produced results that are not consistent with a link between LKB1 gene mutation and PJS. We constructed a knockout gene mutation of Lkb1 to determine whether it is the causative gene of PJS and to examine the biological role of the Lkb1 gene. Lkb1(-/-) mice died in utero between 8.5 and 9.5 days postcoitum. At 9.0 days postcoitum, Lkb1(-/-) embryos were generally smaller than their age-matched littermates, showed developmental retardation, and did not undergo embryonic turning. Multiple gastric adenomatous polyps were observed in 10- to 14-month-old Lkb1(+/-) mice. Our results indicate that functional Lkb1 is required for normal embryogenesis and that it is related to tumor development. The Lkb1(+/-) mouse is suitable for studying molecular mechanism underlying the development of inherited gastric tumors in PJS.     

Analysis of STK11 Gene Variant in Five Chinese Patients with Peutz-Jeghers Syndrome

Background

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant inherited disorder characterized by gastrointestinal hamartomatous polyps and mucocutaneous pigmentation. Germline mutation of a serine/threonine kinase 11(STK11) gene has been identified as a cause of PJS. In this study, we investigated the molecular basis of five Chinese PJS patients.

Methods

Blood samples were collected from five unrelated Chinese PJS patients and their parents. The entire coding region of the STK11 gene was amplified by polymerase chain reaction and analyzed by direct sequencing.

Results

Three different frameshift mutations (c.519insTGTG, c.792_793insT, and c.334_335insC), all of which would cause truncation of the gene product, were found in three patients. One missense mutation (p.Ser307Thr) and one 3bp deletion mutation (c.228–230del CGT) were identified in the remaining two patients. All of the five investigated patients carried de novo mutations.

Conclusions

The results support that mutation of the LKB1 gene is a cause of PJS, and expand the spectrum of the STK11 gene mutations.     

Peutz-Jeghers综合征的研究进展

Peutz-Jeghers综合征（PIS）是一种常染色体显性遗传性疾病,伴有黏膜色素沉着和胃肠道错构瘤性息肉。PJS息肉可发生于整个胃肠道,但多发生于小肠。目前多认为PJS由位于染色体19p13.3的STKll基因突变所致。本文就PJS的致病基因、病理特征、临床诊治等方面的研究进展作一综述。     

A De Novo Mutation of <Emphasis Type="Italic">STK11</Emphasis> Gene in a Chinese Patient with Peutz–Jeghers Syndrome

Peutz–Jeghers syndrome (PJS) is an autosomal-dominant inherited disorder characterized by mucocutaneous pigmentation, hamartomatous polyposis of the gastrointestinal tract, and an increased risk for the development of both gastrointestinal and extraintestinal malignancies. Germline mutation of the STK11 gene, which encodes a serine-threonine kinase, is responsible for PJS. We collected blood samples from a Chinese PJS family consisting of a total of four individuals (one male and three females) including one PJS patient. The whole coding region of STK11 was amplified by polymerase chain reaction and products analyzed by direct sequencing. Molecular analysis of the STK11 gene in this case of PJS revealed a substitution of thymine 217 for adenine (C.217T > A) in exon 1, resulting in a change of codon 73 from cysteine to serine (C73S). The point mutation was not found in normal individuals in this PJS family or in 100 control individuals. The results presented here enlarge the spectrum of mutations of the STK11 gene by identifying a de novo mutation in a PJS patient and further support the hypothesis that STK11 mutations are disease-causing mutations for PJS.     

Novel serine/threonine kinase 11 gene mutations in Peutz-Jeghers syndrome patients and endoscopic management

AIM: To explore mutations in serine/threonine kinase 11 (STK11) gene in Peutz-Jeghers syndrome (PJS) with gastrointestinal (GI) hamartomatous polyps.METHODS: Six Japanese PJS patients in 3 families were enrolled in this study. Each of the cases had hamartomatous polyposis in the gastrointestinal tract, including the small intestine, along with mucocutaneous hyperpigmentation. Narrow-band imaging (NBI)-magnification endoscopy was employed to detect microvascular and microsurface irregularities in the GI lesions. NBI magnification findings could be classified into three groups (type A, type B, or type C). Endoscopic polypectomy was performed using double-balloon enteroscopy or colonoscopy. Genomic DNA was extracted from a whole blood sample from each subject. All of the coding exons of STK11 gene, its boundary regions, and the promoter region containing the polymorphic regions were amplified by polymerase chain reaction, and direct sequencing was performed to assess the germline mutations.RESULTS: NBI-magnification endoscopic observation could detect the abnormalities in microvessels and microsurface structures of GI polyps. Overall, we found 5 cases of type A and one case without the examination for the gastric polyps, while there were 4 cases of type B and 2 case of type A for the colorectal polyps. Seventy-nine small-bowel and 115 colorectal polyps over 27 sessions for each were resected endoscopically without significant complications. The only delayed complication included the occurrence of bleeding in a case, and this was successfully managed with hemoclips. Resected polyps contained no malignant components. Based on mutation analysis, all 3 cases in Family I exhibited the +658C>T nonsense mutation in exon 5, which resulted in the production of a truncated protein (Q220X). In Family II, a case had -252C>A and -193C>A in the promoter region. In Family III, a case was found to have the +1062C>G (F342L) mutation in exon 8.CONCLUSION: We found two novel mutations of STK11 in association with PJS. Endoscopic polypectomy of GI polyps in PJS patients appears to be useful to prevent emergency laparotomies and reduce the cancer risk.     

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 PeutzJeghers 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_del AT) 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.     

Appendiceal carcinoid in a pediatric patient with Peutz-Jeghers syndrome: A case report and comprehensive literature review

Rationale:Peutz-Jeghers syndrome (PJS), a rare autosomal dominant disorder, is characterized by mucocutaneous pigmentations, hamartomatous polyps in the gastrointestinal tract, and a high risk of developing various malignancies. To the best of our knowledge, only 1 case of appendiceal carcinoid associated with PJS has been previously reported in the pediatric population.Patient concerns:We report a 7-year-old girl who was admitted for severe, intermittent abdominal pain and cramps, nausea, and vomiting. Multiple brown melanotic macules on the lips, buccal mucosa, and the tongue were noted.Diagnosis:A plain abdominal X-ray in a standing position revealed dilated intestinal loops with multiple air-fluid levels. A computed tomography scan of the abdomen showing a “coffee bean” appearance of the jejunal loop with a transition point to the duodenal loop. Axial-contrast-enhanced computed tomography scan of the abdomen showing dilated jejunum loops, filled with fluid with the swirled appearance of mesentery typical for volvulus. The diagnosis of PJS was based on clinical findings along with the histopathologic confirmation of the hamartomatous polyps.Interventions:An emergency laparotomy was performed, revealing a jejunojejunal intussusception starting 40 cm from the duodenojejunal flexure. Jejunotomy revealed that a lead-point intussusception was a necrotic hamartomatous polyp. After resecting the involved jejunal necrotic segment, including the polyp, end-to-end jejuno-jejunal anastomosis was performed. Further exploration revealed the presence of a jejunal mass 80 cm from the duodenojejunal flexure identified as another hamartomatous pedunculated polyp. The polyp was resected, and the enterotomy was then closed transversely. The grossly normal appendix was also removed.Outcomes:Clinical findings along with the histopathologically confirmed hamartomatous polyps were consistent with PJS. An appendiceal carcinoid (well-differentiated neuroendocrine tumor, European Neuroendocrine Tumor Society stage pT2) was incidentally detected during histological examination of the appendix. The patient and parents were counseled accordingly, focusing on active surveillance and control of symptoms. Two additional hamartomatous polyps (gastric and jejunal) were detected endoscopically and resected in the fourth postoperative week. A regular, 1-year follow-up and surveillance revealed no complications or recurrences.Lessons:Unusual neoplasms can occasionally be encountered in well-defined syndromes such as PJS. Therefore, active follow-up and surveillance are mandatory for all patients with PJS.     

Mucosal prolapse in the pathogenesis of Peutz-Jeghers polyposis

Germline mutations in LKB1 cause the rare cancer prone disorder Peutz-Jeghers syndrome (PJS). Gastrointestinal hamartomatous polyps constitute the major phenotypic trait in PJS. Hamartomatous polyps arising in PJS patients are generally considered to lack premalignant potential although rare neoplastic changes in these polyps and an increased gastrointestinal cancer risk in PJS are well documented. These conflicting observations are resolved in the current hypothesis by providing a unifying explanation for these contrasting features of PJS polyposis. We postulate that a genetic predisposition to epithelial prolapse underlies the formation of the polyps associated with PJS. Conventional sporadic adenomas arising in PJS patients will similarly show mucosal prolapse and carry the associated histological features.     

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 PeutzJeghers 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: molecular analysis of a three-generation kindred with a novel defect in the serine threonine kinase gene STK11

The Peutz-Jeghers syndrome, phenotypically characterized by mucocutaneous pigmentation and hamartomatous polyposis, is an autosomal dominant disease with variable expression and incomplete penetrance. Moreover, affected patients are at increased risk for gastrointestinal and other malignancies. Recently, a mutated gene encoding abnormal forms of the novel serine threonine kinase STK11 has been identified as a genetic cause of Peutz-Jeghers syndrome. Here, we report the molecular analysis of the STK11 gene in a patient with Peutz-Jeghers syndrome, which in exon 1 revealed a guanine (G) insertion in the 5 G repeat of codons 51–53. The insertion leads to a frameshift with a premature TGA stop codon 324 bp downstream in codon 162, predicting the expression of a truncated protein without kinase activity. This heterozygous germline mutation was also found in the affected father and in one affected sister of the index patient, but not in any phenotypically unaffected family member or in unrelated control subjects. In DNA isolated from microdissected hamartomatous polyps of the index patient, exon 1 of the STK11 gene could not be amplified suggesting that both alleles of STK11 exon 1 were lost in the hamartomatous polyps. Identification of a STK11 gene mutation in an index patient offers the possibility of a predictive diagnosis, and initiation of specific screening programs in the genetically affected kindred.     

Prepubertal gynecomastia in two monozygotic twins with Peutz-Jeghers syndrome: two years' treatment with anastrozole and genetic study

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant disorder characterized by multiple gastrointestinal hamartomatous polyps, mucocutaneous pigmentation and increased predisposition to neoplasms. Endocrine manifestations in PJS include gynecomastia and advanced bone age due to estrogen production by large-cell calcifying Sertoli cell tumors (LSCT). We present two 9-year-old male monozygotic twins, with PJS, bilateral progressive prepubertal gynecomastia and testicular bilateral multifocal calcifications, suggesting a diagnosis of LSCT. Their father had PJS but no history of gynecomastia or testicular calcifications. No mutations were found in the tumor suppressor gene LKB1/STK11, which is responsible for about 60% of PJS cases. The genotype of the aromatase cytochrome P450 19, a key enzyme involved in estrogen biosynthesis, was the same in the father and his twins. To reduce gynecomastia and delay skeletal maturation, the children started treatment with anastrozole, an aromatase inhibitor. Growth velocity decreased and gynecomastia diminished. After 2 years of treatment, anastrozole is still currently used at a dosage of 1 mg once daily with no side effects. In this study, a couple of monozygotic twins with PJS, prepubertal gynecomastia and LSCT is reported for the first time and anastrozole appears to be an efficacious medical treatment, as an alternative to orchidectomy, to control the effects of estrogen excess.