Morphologic Characterization of Hamartomatous Gastrointestinal Polyps in Cowden Syndrome, Peutz-Jeghers Syndrome and Juvenile Polyposis Syndrome Ruthy Shaco-Levy MD, Kory W. Jasperson MS, CGC, Katie Martin MD, N. Jewel Samadder MD, Randall W. Burt MD, Jian Ying PhD, Mary P. Bronner MD PII: DOI: Reference:
S0046-8177(15)00429-3 doi: 10.1016/j.humpath.2015.10.002 YHUPA 3732
To appear in:
Human Pathology
Received date: Revised date: Accepted date:
16 May 2015 5 October 2015 8 October 2015
Please cite this article as: Shaco-Levy Ruthy, Jasperson Kory W., Martin Katie, Samadder N. Jewel, Burt Randall W., Ying Jian, Bronner Mary P., Morphologic Characterization of Hamartomatous Gastrointestinal Polyps in Cowden Syndrome, PeutzJeghers Syndrome and Juvenile Polyposis Syndrome, Human Pathology (2015), doi: 10.1016/j.humpath.2015.10.002
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Morphologic Characterization of Hamartomatous Gastrointestinal Polyps in Cowden Syndrome, Peutz-Jeghers Syndrome and Juvenile Polyposis Syndrome Ruthy Shaco-Levy, MD, 3,4 Kory W. Jasperson, MS, CGC, 4 Katie Martin, MD, 3,5,6 N. Jewel
T
1,2,3
RI P
Samadder, MD, 3,5,6 Randall W. Burt, MD, 3,5,7 Jian Ying, PhD, 2,3 Mary P. Bronner, MD 1
Department of Pathology, Soroka Medical Center, Ben-Gurion University of the Negev, Beer
SC
Sheva, 84101, Israel; 2Department of Pathology & ARUP Laboratories, 3Huntsman Cancer
MA NU
Institute, 4Genetic Counseling, 5Department of Internal Medicine, 6Division of Gastroenterology, 7Division of Epidemiology, University of Utah, Salt Lake City, UT, 84112, USA.
Keywords: Cowden syndrome, Peutz-Jeghers Syndrome, Juvenile Polyposis Syndrome ,
ED
hamartoma, polyp.
PT
Running title: Hamartomatous Gastrointestinal Polyposis
CE
Conflict of Interest: None
Funding: We acknowledge support of funds and use of the Biorepository and Molecular
AC
Pathology, in addition to the Genetic Counseling shared resources, supported by NCI grant 5P30CA042014-22, awarded to the Huntsman Cancer Institute and to the Gastrointestinal Cancer Program at Huntsman Cancer Institute. Abstract: The morphological features of the gastrointestinal polyps in hamartomatous polyposis syndromes are poorly defined. Our aim was to better characterize the gastrointestinal hamartomas in these syndromes. A blinded review was performed regarding many histological features for every polyp. The study included 15 Cowden syndrome (CS), 13 Peutz-Jegher's (PJS), 12 juvenile polyposis (JuvPS) patients, and 32 cases of sporadic 1
ACCEPTED MANUSCRIPT hamartomatous polyps. A total of 375 polyps were examined. CS polyps were characteristically colonic, sessile, small, without surface erosion, showing mildly inflamed
T
fibrotic lamina propria with smooth muscle proliferation and lymphoid follicles. They
RI P
showed the least degree of cystic glands and had no thick mucin. Uncommon but specific features were ganglion cells and nerve fibers within the lamina propria and mucosal fat. PJS
SC
polyps were typically of small or large bowel origin, often exophytic, seldom eroded, with inflamed edematous and fibrotic lamina propria and dilated cystic glands filled with often
MA NU
thick mucin. All PJS polyps showed smooth muscle proliferation, frequently widespread. The polyps of JuvPS were typically colonic, large, exophytic, eroded, with strikingly edematous, fibrotic markedly inflamed lamina propria, cystic glands filled with frequently thick mucin, and the least degree of smooth muscle proliferation. Non-syndromic hamartomatous polyps
ED
were similar to JuvPS polyps; however, they were more often colonic, smaller, showed more widespread smooth muscle proliferation, and were less likely to contain thick mucin. In
PT
conclusion, we were able to define the characteristic hamartomatous polyp for each
CE
hamartomatous polyposis syndrome. Awareness to these features may aid in the diagnosis
AC
of these rare syndromes. Introduction:
The hamartomatous polyposis syndromes comprise a diverse group of genetic,
clinical and pathologic entities. The most common and important, due to their increased cancer rates, are Cowden's syndrome (CS), Peutz-Jegher's syndrome (PJS), and juvenile polyposis syndrome (JuvPS) [1-5]. CS, an autosomal dominant condition affecting 1 in 200,000 people, is characterized by multiple hamartomatous lesions [1-7]. Gastrointestinal (GI) polyposis is a common manifestation, can occur throughout the GI tract, and is reported to have a markedly varied histology, with predominantly hamartomatous but also adenomatous, inflammatory, 2
ACCEPTED MANUSCRIPT hyperplastic, lipomatous and ganglioneuromatous polyps [5-7]. Consensus criteria have been established to assist in the diagnosis of CS, which frequently presents with various
T
signs and symptoms [2, 8]. CS patients are at particularly high risk of developing cancer of
RI P
the breast, thyroid, ovary, endometrium, uterine cervix, and urinary bladder [1-5, 7]. CS probably also confers a risk of colorectal cancer [6]. Germline mutations in the PTEN
SC
(phosphatase and tensin homolog) tumor suppressor gene located on chromosome 10q are found in approximately 80% of patients with CS [5, 7].
MA NU
PJS is an autosomal dominant inherited hamartomatous polyposis syndrome with a prevalence of approximately 1 in 200,000. PJS is characterized by melanotic mucocutaneous hyperpigmentation, which often fades with age, and GI hamartomatous polyps, mostly in
ED
the small bowel but also in the colon and stomach [7, 9-11]. These hamartomatous polyps can cause abdominal pain and intussusception, sometimes leading to bowel obstruction and
PT
severe GI bleeding [10]. PJS is now recognized as a cancer predisposition syndrome, since these patients are at very high relative risk for colorectal cancer and a variety of extracolonic
CE
malignancies. The malignancies recognized include breast, pancreas, thyroid, stomach, small
AC
intestine, ovary, endometrium, uterine cervix, testis, multiple myeloma and skin [11-13]. Patients with PJS have a 93% cumulative lifetime risk for cancer [14, 15], including an almost 70% risk of GI cancer [2, 3]. Germline mutations in the tumor suppressor gene STK11/LKB1 gene on chromosome 19p are responsible for the PJS [16]. These mutations are found in up to 80% of affected individuals; up to 25% of documented cases are sporadic [7, 15]. JuvPS, the most common of the hamartomatous polyposis syndromes, affects 1 in 100,000 and occurs as an autosomal-dominant inherited disorder in approximately 30% of the patients; the remaining cases represent de-novo mutation [15, 17]. JuvPS is characterized by the presence of multiple hamartomatous polyps affecting the colon and rectum. Unlike sporadic colorectal juvenile polyps, which are relatively common, occurring in
3
ACCEPTED MANUSCRIPT up to 2% of children younger than 10 years of age, the polyps of JuvPS are more numerous and may affect the proximal GI tract polyps [3, 5, and 16]. Patients with JuvPS are at
T
increased risk of colorectal, pancreatic and upper GI cancer, with an overall risk of GI
RI P
malignancies at 55% [7, 15, 18, and 19]. Both sporadic and inherited forms share similar genetics: germline mutations of SMAD4 (Mothers against Decapentaplegic Homolog4, also
SC
known as MADH4 and DPC4), located on the chromosome 18q, are detected in approximately 15% of patients with JuvPS. The BMPR1A gene (Bone Morphogenetic Protein
MA NU
Receptor-Type 1A), located on chromosome 10q, is mutated in about 25% of JuvPS patients [15, 20, 21]. ENG germline mutations have been found in JuvPS presenting in early childhood [18]. All 3 genetic changes cause disruption of the TGFb (transforming growth factor beta)
ED
signal transduction pathway [22].
Pathologists frequently fail to raise the suspicion of a hamartomatous polyposis
PT
syndrome based on the gastrointestinal polyps' morphology. CS polyps are sometimes interpreted as hyperplastic polyps, juvenile polyps or merely hamartomatous polyps [7, 23].
CE
Patients with CS can present with multiple juvenile colonic polyps and therefore be
AC
misdiagnosed as having JuvPS [3]. Also, although PJS polyps are thought to demonstrate characteristic histological features, with "classic" tree branchlike pattern, this arborizing smooth muscle configuration is more pronounced in the small intestine than in the colon, where these polyps may be misdiagnosed as mucosal prolapse polyp [24]. Furthermore, as there are no known histological differences between sporadic and syndromic juvenile polyps, it is currently not possible to raise the suspicion of JuvPS based on a solitary or even a couple of colorectal juvenile polyps [7]. The genetic bases have been determined in large part for all of these syndromes. However, careful systematic genotype-phenotype analysis specifically of gastrointestinal polyp morphology has not been done. The prevalence of various morphologic features of
4
ACCEPTED MANUSCRIPT these polyps in known genetic backgrounds remains poorly defined. This needs to be rectified as polyp morphology is one of the major factors contributing to correct diagnosis,
T
clinical management and research study design in these syndromes. Appropriate
RI P
identification of individuals and families affected with these syndromes is crucial as these syndromes are associated with high rates of malignancy and a thorough cancer screening is
SC
necessary in order to enhance the opportunity for early detection [2].
The aim of this study was to systematically review the histological features of JuvPS,
MA NU
PJS, CS, and non-syndromic hamartomatous polyps within the University of Utah polyposis registry and surgical pathology archives, blinded to known genetic and clinical syndromic backgrounds, to assess the value of histologic features for diagnostic utility.
ED
Materials and Methods:
PT
Approval for the conduction of this study was obtained by the University of Utah's Institutional Review Board. The pathology database at the University of Utah Medical Center
CE
was searched from January 2000 to December 2011 using the terms "hamartomatous polyp(s)", "juvenile polyp(s)", "peutz-Jegher's syndrome", "Cowden Syndrome" and
AC
"intestinal ganglioneuroma". This search yielded 476 cases that were then scanned by the Clinical Genetics Department, in order to identify those who have confirmed CS, PJS, or JuvPS, either by a genetic mutation or by clinical criteria. Among the non-syndromic cases, 45 that matched the polyposis cases by age were selected to serve as a control group. After comprehensive review of their medical charts, 32 were confirmed as definite sporadic cases. The archival histologic slides from the 4 groups (CS, PJS, JuvPS, and non-syndromic patients) were obtained and intermixed with each other. A systematic review was performed by 2 pathologists with interest in gastrointestinal pathology using a doubleheaded microscope, and a consensus regarding each of the following histological features
5
ACCEPTED MANUSCRIPT was rendered for every polyp. The gross features recorded were total number of polyps, their location, polyp size, and configuration (exophytic/sessile). The microscopic features
T
examined included surface erosion, expanded and inflamed lamina propria, active
RI P
inflammation, expanded edematous lamina propria, expanded fibrotic lamina propria, smooth muscle fibers in the lamina propria, glandular distortion, dilated cystic glands, mucin
SC
in cystic glands, serrated architecture, thick intra-luminal mucin (defined as dense deeply eosinophilic mucin), "onion-skin" arrangement of fibroblasts around glands, lobular clusters
MA NU
of glands, stromal ganglion cells, nerve fiber proliferation in the lamina propria, lymphoid follicles, mucosal stromal fat, mild (low-grade) dysplasia, and severe (high-grade) dysplasia. For each feature the diagnosis given was either present or absent, except smooth muscle fibers in the lamina propria that was graded as follows: zero for absence of smooth muscle
ED
fibers in the lamina propria, 1 when scattered delicate fibers were present, and 2 when conspicuous broad strands of smooth muscle crossed the lamina propria. The review was
PT
blinded to knowledge of the clinical syndrome and genetics.
CE
The catalogued histological features were then analyzed for prevalence in each
AC
group. The prevalence was then compared between the 4 groups in an attempt to find features that differ significantly between the groups, in order to better define diagnostic polyp morphology relative to known genetic and clinical backgrounds. Genetic analysis of PTEN, STK11, and SMAD4: Genetic testing of PTEN, STK11, and SMAD4 was performed using standard clinical techniques, which typically consisted of sequencing of all exons and adjacent introns, in addition to large rearrangement testing. Or in the case of a known mutation in the family, site specific testing for the familial mutation may have been performed. Statistical analysis:
6
ACCEPTED MANUSCRIPT The proportion of polyps with interested features was calculated for each of the 4 groups. The difference of the proportion among the 4 groups was assessed by permutation
T
of group at individual level. Specifically, observed chi-square statistic was calculated from
RI P
the original data. The symptom group of each subject was permuted and chi-square statistic was calculated for the permutated data. 1000 permutations performed for 1000 times and p
SC
value was calculated the proportion of the permuted statistic that not less than observed statistic. This permutation method was applied to all comparison of proportion on interested
the lamina propria and location. Results:
MA NU
feathers. Fisher exact test was used to assess the association between smooth muscle in
ED
The group of patients with clinically confirmed hamartomatous polyposis syndromes included 15 with CS from 14 different families (9 confirmed mutations; 6 clinical diagnoses),
PT
13 with PJS from 11 different families (8 confirmed mutations; 5 clinical diagnoses), and 12
CE
with JuvPS from 10 different families (6 confirmed mutations; 6 clinical diagnoses). Thirty two cases of sporadic hamartomatous polyps served as a control group. A total of 375 polyps
AC
were examined. Table 1 summarizes the various polyps seen in each category. Hamartomatous and juvenile polyps comprised the vast majority of polyp type in each group. A polyp was classified as juvenile polyp if it had the characteristic features: cystically dilated glands filled with mucus, separated by an inflamed and edematous stroma. Hamartomatous polyps without these features were classified as hamartoma. Table 2 compares the various gross and histological features between the 4 groups. Colonic predominance with >75% colonic polyps and
S0046-8177(15)00429-3 doi: 10.1016/j.humpath.2015.10.002 YHUPA 3732
To appear in:
Human Pathology
Received date: Revised date: Accepted date:
16 May 2015 5 October 2015 8 October 2015
Please cite this article as: Shaco-Levy Ruthy, Jasperson Kory W., Martin Katie, Samadder N. Jewel, Burt Randall W., Ying Jian, Bronner Mary P., Morphologic Characterization of Hamartomatous Gastrointestinal Polyps in Cowden Syndrome, PeutzJeghers Syndrome and Juvenile Polyposis Syndrome, Human Pathology (2015), doi: 10.1016/j.humpath.2015.10.002
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Morphologic Characterization of Hamartomatous Gastrointestinal Polyps in Cowden Syndrome, Peutz-Jeghers Syndrome and Juvenile Polyposis Syndrome Ruthy Shaco-Levy, MD, 3,4 Kory W. Jasperson, MS, CGC, 4 Katie Martin, MD, 3,5,6 N. Jewel
T
1,2,3
RI P
Samadder, MD, 3,5,6 Randall W. Burt, MD, 3,5,7 Jian Ying, PhD, 2,3 Mary P. Bronner, MD 1
Department of Pathology, Soroka Medical Center, Ben-Gurion University of the Negev, Beer
SC
Sheva, 84101, Israel; 2Department of Pathology & ARUP Laboratories, 3Huntsman Cancer
MA NU
Institute, 4Genetic Counseling, 5Department of Internal Medicine, 6Division of Gastroenterology, 7Division of Epidemiology, University of Utah, Salt Lake City, UT, 84112, USA.
Keywords: Cowden syndrome, Peutz-Jeghers Syndrome, Juvenile Polyposis Syndrome ,
ED
hamartoma, polyp.
PT
Running title: Hamartomatous Gastrointestinal Polyposis
CE
Conflict of Interest: None
Funding: We acknowledge support of funds and use of the Biorepository and Molecular
AC
Pathology, in addition to the Genetic Counseling shared resources, supported by NCI grant 5P30CA042014-22, awarded to the Huntsman Cancer Institute and to the Gastrointestinal Cancer Program at Huntsman Cancer Institute. Abstract: The morphological features of the gastrointestinal polyps in hamartomatous polyposis syndromes are poorly defined. Our aim was to better characterize the gastrointestinal hamartomas in these syndromes. A blinded review was performed regarding many histological features for every polyp. The study included 15 Cowden syndrome (CS), 13 Peutz-Jegher's (PJS), 12 juvenile polyposis (JuvPS) patients, and 32 cases of sporadic 1
ACCEPTED MANUSCRIPT hamartomatous polyps. A total of 375 polyps were examined. CS polyps were characteristically colonic, sessile, small, without surface erosion, showing mildly inflamed
T
fibrotic lamina propria with smooth muscle proliferation and lymphoid follicles. They
RI P
showed the least degree of cystic glands and had no thick mucin. Uncommon but specific features were ganglion cells and nerve fibers within the lamina propria and mucosal fat. PJS
SC
polyps were typically of small or large bowel origin, often exophytic, seldom eroded, with inflamed edematous and fibrotic lamina propria and dilated cystic glands filled with often
MA NU
thick mucin. All PJS polyps showed smooth muscle proliferation, frequently widespread. The polyps of JuvPS were typically colonic, large, exophytic, eroded, with strikingly edematous, fibrotic markedly inflamed lamina propria, cystic glands filled with frequently thick mucin, and the least degree of smooth muscle proliferation. Non-syndromic hamartomatous polyps
ED
were similar to JuvPS polyps; however, they were more often colonic, smaller, showed more widespread smooth muscle proliferation, and were less likely to contain thick mucin. In
PT
conclusion, we were able to define the characteristic hamartomatous polyp for each
CE
hamartomatous polyposis syndrome. Awareness to these features may aid in the diagnosis
AC
of these rare syndromes. Introduction:
The hamartomatous polyposis syndromes comprise a diverse group of genetic,
clinical and pathologic entities. The most common and important, due to their increased cancer rates, are Cowden's syndrome (CS), Peutz-Jegher's syndrome (PJS), and juvenile polyposis syndrome (JuvPS) [1-5]. CS, an autosomal dominant condition affecting 1 in 200,000 people, is characterized by multiple hamartomatous lesions [1-7]. Gastrointestinal (GI) polyposis is a common manifestation, can occur throughout the GI tract, and is reported to have a markedly varied histology, with predominantly hamartomatous but also adenomatous, inflammatory, 2
ACCEPTED MANUSCRIPT hyperplastic, lipomatous and ganglioneuromatous polyps [5-7]. Consensus criteria have been established to assist in the diagnosis of CS, which frequently presents with various
T
signs and symptoms [2, 8]. CS patients are at particularly high risk of developing cancer of
RI P
the breast, thyroid, ovary, endometrium, uterine cervix, and urinary bladder [1-5, 7]. CS probably also confers a risk of colorectal cancer [6]. Germline mutations in the PTEN
SC
(phosphatase and tensin homolog) tumor suppressor gene located on chromosome 10q are found in approximately 80% of patients with CS [5, 7].
MA NU
PJS is an autosomal dominant inherited hamartomatous polyposis syndrome with a prevalence of approximately 1 in 200,000. PJS is characterized by melanotic mucocutaneous hyperpigmentation, which often fades with age, and GI hamartomatous polyps, mostly in
ED
the small bowel but also in the colon and stomach [7, 9-11]. These hamartomatous polyps can cause abdominal pain and intussusception, sometimes leading to bowel obstruction and
PT
severe GI bleeding [10]. PJS is now recognized as a cancer predisposition syndrome, since these patients are at very high relative risk for colorectal cancer and a variety of extracolonic
CE
malignancies. The malignancies recognized include breast, pancreas, thyroid, stomach, small
AC
intestine, ovary, endometrium, uterine cervix, testis, multiple myeloma and skin [11-13]. Patients with PJS have a 93% cumulative lifetime risk for cancer [14, 15], including an almost 70% risk of GI cancer [2, 3]. Germline mutations in the tumor suppressor gene STK11/LKB1 gene on chromosome 19p are responsible for the PJS [16]. These mutations are found in up to 80% of affected individuals; up to 25% of documented cases are sporadic [7, 15]. JuvPS, the most common of the hamartomatous polyposis syndromes, affects 1 in 100,000 and occurs as an autosomal-dominant inherited disorder in approximately 30% of the patients; the remaining cases represent de-novo mutation [15, 17]. JuvPS is characterized by the presence of multiple hamartomatous polyps affecting the colon and rectum. Unlike sporadic colorectal juvenile polyps, which are relatively common, occurring in
3
ACCEPTED MANUSCRIPT up to 2% of children younger than 10 years of age, the polyps of JuvPS are more numerous and may affect the proximal GI tract polyps [3, 5, and 16]. Patients with JuvPS are at
T
increased risk of colorectal, pancreatic and upper GI cancer, with an overall risk of GI
RI P
malignancies at 55% [7, 15, 18, and 19]. Both sporadic and inherited forms share similar genetics: germline mutations of SMAD4 (Mothers against Decapentaplegic Homolog4, also
SC
known as MADH4 and DPC4), located on the chromosome 18q, are detected in approximately 15% of patients with JuvPS. The BMPR1A gene (Bone Morphogenetic Protein
MA NU
Receptor-Type 1A), located on chromosome 10q, is mutated in about 25% of JuvPS patients [15, 20, 21]. ENG germline mutations have been found in JuvPS presenting in early childhood [18]. All 3 genetic changes cause disruption of the TGFb (transforming growth factor beta)
ED
signal transduction pathway [22].
Pathologists frequently fail to raise the suspicion of a hamartomatous polyposis
PT
syndrome based on the gastrointestinal polyps' morphology. CS polyps are sometimes interpreted as hyperplastic polyps, juvenile polyps or merely hamartomatous polyps [7, 23].
CE
Patients with CS can present with multiple juvenile colonic polyps and therefore be
AC
misdiagnosed as having JuvPS [3]. Also, although PJS polyps are thought to demonstrate characteristic histological features, with "classic" tree branchlike pattern, this arborizing smooth muscle configuration is more pronounced in the small intestine than in the colon, where these polyps may be misdiagnosed as mucosal prolapse polyp [24]. Furthermore, as there are no known histological differences between sporadic and syndromic juvenile polyps, it is currently not possible to raise the suspicion of JuvPS based on a solitary or even a couple of colorectal juvenile polyps [7]. The genetic bases have been determined in large part for all of these syndromes. However, careful systematic genotype-phenotype analysis specifically of gastrointestinal polyp morphology has not been done. The prevalence of various morphologic features of
4
ACCEPTED MANUSCRIPT these polyps in known genetic backgrounds remains poorly defined. This needs to be rectified as polyp morphology is one of the major factors contributing to correct diagnosis,
T
clinical management and research study design in these syndromes. Appropriate
RI P
identification of individuals and families affected with these syndromes is crucial as these syndromes are associated with high rates of malignancy and a thorough cancer screening is
SC
necessary in order to enhance the opportunity for early detection [2].
The aim of this study was to systematically review the histological features of JuvPS,
MA NU
PJS, CS, and non-syndromic hamartomatous polyps within the University of Utah polyposis registry and surgical pathology archives, blinded to known genetic and clinical syndromic backgrounds, to assess the value of histologic features for diagnostic utility.
ED
Materials and Methods:
PT
Approval for the conduction of this study was obtained by the University of Utah's Institutional Review Board. The pathology database at the University of Utah Medical Center
CE
was searched from January 2000 to December 2011 using the terms "hamartomatous polyp(s)", "juvenile polyp(s)", "peutz-Jegher's syndrome", "Cowden Syndrome" and
AC
"intestinal ganglioneuroma". This search yielded 476 cases that were then scanned by the Clinical Genetics Department, in order to identify those who have confirmed CS, PJS, or JuvPS, either by a genetic mutation or by clinical criteria. Among the non-syndromic cases, 45 that matched the polyposis cases by age were selected to serve as a control group. After comprehensive review of their medical charts, 32 were confirmed as definite sporadic cases. The archival histologic slides from the 4 groups (CS, PJS, JuvPS, and non-syndromic patients) were obtained and intermixed with each other. A systematic review was performed by 2 pathologists with interest in gastrointestinal pathology using a doubleheaded microscope, and a consensus regarding each of the following histological features
5
ACCEPTED MANUSCRIPT was rendered for every polyp. The gross features recorded were total number of polyps, their location, polyp size, and configuration (exophytic/sessile). The microscopic features
T
examined included surface erosion, expanded and inflamed lamina propria, active
RI P
inflammation, expanded edematous lamina propria, expanded fibrotic lamina propria, smooth muscle fibers in the lamina propria, glandular distortion, dilated cystic glands, mucin
SC
in cystic glands, serrated architecture, thick intra-luminal mucin (defined as dense deeply eosinophilic mucin), "onion-skin" arrangement of fibroblasts around glands, lobular clusters
MA NU
of glands, stromal ganglion cells, nerve fiber proliferation in the lamina propria, lymphoid follicles, mucosal stromal fat, mild (low-grade) dysplasia, and severe (high-grade) dysplasia. For each feature the diagnosis given was either present or absent, except smooth muscle fibers in the lamina propria that was graded as follows: zero for absence of smooth muscle
ED
fibers in the lamina propria, 1 when scattered delicate fibers were present, and 2 when conspicuous broad strands of smooth muscle crossed the lamina propria. The review was
PT
blinded to knowledge of the clinical syndrome and genetics.
CE
The catalogued histological features were then analyzed for prevalence in each
AC
group. The prevalence was then compared between the 4 groups in an attempt to find features that differ significantly between the groups, in order to better define diagnostic polyp morphology relative to known genetic and clinical backgrounds. Genetic analysis of PTEN, STK11, and SMAD4: Genetic testing of PTEN, STK11, and SMAD4 was performed using standard clinical techniques, which typically consisted of sequencing of all exons and adjacent introns, in addition to large rearrangement testing. Or in the case of a known mutation in the family, site specific testing for the familial mutation may have been performed. Statistical analysis:
6
ACCEPTED MANUSCRIPT The proportion of polyps with interested features was calculated for each of the 4 groups. The difference of the proportion among the 4 groups was assessed by permutation
T
of group at individual level. Specifically, observed chi-square statistic was calculated from
RI P
the original data. The symptom group of each subject was permuted and chi-square statistic was calculated for the permutated data. 1000 permutations performed for 1000 times and p
SC
value was calculated the proportion of the permuted statistic that not less than observed statistic. This permutation method was applied to all comparison of proportion on interested
the lamina propria and location. Results:
MA NU
feathers. Fisher exact test was used to assess the association between smooth muscle in
ED
The group of patients with clinically confirmed hamartomatous polyposis syndromes included 15 with CS from 14 different families (9 confirmed mutations; 6 clinical diagnoses),
PT
13 with PJS from 11 different families (8 confirmed mutations; 5 clinical diagnoses), and 12
CE
with JuvPS from 10 different families (6 confirmed mutations; 6 clinical diagnoses). Thirty two cases of sporadic hamartomatous polyps served as a control group. A total of 375 polyps
AC
were examined. Table 1 summarizes the various polyps seen in each category. Hamartomatous and juvenile polyps comprised the vast majority of polyp type in each group. A polyp was classified as juvenile polyp if it had the characteristic features: cystically dilated glands filled with mucus, separated by an inflamed and edematous stroma. Hamartomatous polyps without these features were classified as hamartoma. Table 2 compares the various gross and histological features between the 4 groups. Colonic predominance with >75% colonic polyps and
