Summary Benign serrated polyps are commonly found in the colorectum but have rarely been described in other parts of the gastrointestinal tract. We report a series of 9 serrated polyps arising in the ...duodenum with clinicopathologic features, immunohistochemical expression profile of mucins (MUC2, MUC5AC, MUC6), and molecular analysis for BRAF and KRAS . The polyps were diagnosed as incidental endoscopy findings in 9 different patients, comprising 3 male and 6 female patients, with a mean age of 52.2 years (range, 21-72 years). The second part of the duodenum was the most common site (n = 5), followed by the ampulla (n = 1) and the distal duodenum (n = 1), with the location of the 2 remaining polyps unspecified. Other upper gastrointestinal tract pathology features included Barrett esophagus for 5 patients, Helicobacter gastritis for 1 patient, and mild chronic gastritis for 1 patient. The histologic appearance of the polyps was similar to microvesicular hyperplastic polyp in the colorectum. Immunostaining for mucins showed MUC6 expression in the crypt bases of all polyps, MUC5AC expression in 8 cases (89%), and mucin 2 expression in 6 cases (67%). Molecular testing was successful in 6 polyps, showing BRAF mutation (V600E) in 2 polyps, KRAS mutation in 2 polyps, and no mutation for either gene in 2 polyps. Colonoscopy reports were available for 6 patients, of whom 4 were diagnosed with hyperplastic polyps or sessile serrated polyps in the colorectum. However, no patient met the criteria for serrated polyposis. Although probably rare and of uncertain malignant potential, hyperplastic polyp should be considered in the differential diagnosis of benign duodenal polyp.
Sessile serrated adenomas (SSAs) are the precursors of at least 15% of colorectal carcinomas, but their biology is incompletely understood. We performed a clinicopathological and molecular analysis ...of a large number of the rarely observed SSAs with dysplasia/carcinoma to better define their features and the pathways by which they progress to carcinoma.
A cross-sectional analysis of 137 SSAs containing regions of dysplasia/carcinoma prospectively collected at a community GI pathology practice was conducted. Samples were examined for BRAF and KRAS mutations, the CpG island methylator phenotype (CIMP) and immunostained for MLH1, p53, p16, β-catenin and 0-6-methylguanine DNA methyltransferase (MGMT).
The median polyp size was 9 mm and 86.5% were proximal. Most were BRAF mutated (92.7%) and 94.0% showed CIMP. Mismatch repair deficiency, evidenced by loss of MLH1 (74.5%) is associated with older age (76.7 versus 71.0; p<0.0029), female gender (70% versus 36%; p<0.0008), proximal location (91% versus 72%; p<0.02), CIMP (98% versus 80%; p<0.02) and lack of aberrant p53 (7% versus 34%; p<0.001) when compared with the mismatch repair-proficient cases. Loss of p16 (43.1%) and gain of nuclear β-catenin (55.5%) were common in areas of dysplasia/cancer, irrespective of mismatch repair status.
SSAs containing dysplasia/carcinoma are predominantly small (<10 mm) and proximal. The mismatch repair status separates these lesions into distinct clinicopathological subgroups, although WNT activation and p16 silencing are common to both. Cases with dysplasia occur at a similar age to cases with carcinoma. This, together with the rarity of these 'caught in the act' lesions, suggests a rapid transition to malignancy following a long dwell time as an SSA without dysplasia.
Cystic lesions of the retrorectal space Brown, Ian S; Sokolova, Anna; Rosty, Christophe ...
Histopathology,
January 2023, 2023-Jan, 2023-01-00, 20230101, Letnik:
82, Številka:
2
Journal Article
Recenzirano
Cysts of the retrorectal space comprise a heterogeneous group of rare lesions. Most develop from embryological remnants and include tailgut cysts, dermoid cysts, rectal duplication cysts, anal canal ...duplication cysts, sacrococcygeal teratomas and anterior meningocoele. Tailgut cyst is the most common cyst of developmental origin, usually presenting as a multilocular cystic mass with mucoid content and lined by multiple epithelial types. Compared with tailgut cysts, rectal duplication cysts display all layers of the large bowel wall including a well‐defined muscularis propria. Retrorectal cysts of non‐developmental origin are far less common and represent lesions that either infrequently involve the retrorectal space or undergo extensive cystic change. This review provides an overview of the various histological types of cystic lesions of the retrorectal space, divided into cysts of developmental origin and those of non‐developmental origin. A practical pathological and multidisciplinary approach to diagnosing these lesions is presented.
Pathological features of retrorectal cysts.
Gastrointestinal polyposis disorders are a group of syndromes defined by clinicopathologic features that include the predominant histologic type of colorectal polyp and specific inherited gene ...mutations. Adenomatous polyposis syndromes comprise the prototypical familial adenomatous polyposis syndrome and other recently identified genetic conditions inherited in a dominant or recessive manner. Serrated polyposis syndrome is defined by arbitrary clinical criteria. The diagnosis of hamartomatous polyposis syndromes can be suggested from the histologic characteristics of colorectal polyps and the association with various extraintestinal manifestations. Proper identification of affected individuals is important due to an increased risk of gastrointestinal and extragastrointestinal cancers.
We have previously reported activating mutations of the gene coding for the fibroblast growth factor receptor 3 (FGFR3) in invasive cervical carcinoma. To further analyze the role of FGFR3 in ...cervical tumor progression, we extended our study to screen a total of 75 invasive tumors and 80 cervical intraepithelial neoplasias (40 low-grade and 40 high-grade lesions).
Using single strand conformation polymorphism (SSCP) followed by DNA sequencing, we found FGFR3 mutation (S249C in all cases) in 5% of invasive cervical carcinomas and no mutation in intraepithelial lesions. These results suggest that, unlike in bladder carcinoma, FGFR3 mutation does not or rarely occur in non invasive lesions. Compared to patients with wildtype FGFR3 tumor, patients with S249C FGFR3 mutated tumors were older (mean age 64 vs. 49.4 years, P = 0.02), and were more likely to be associated with a non-16/18 HPV type in their tumor. Gene expression analysis demonstrated that FGFR3 mutated tumors were associated with higher FGFR3b mRNA expression levels compared to wildtype FGFR3 tumors. Supervised analysis of Affymetrix expression data identified a significant number of genes specifically differentially expressed in tumors with respect to FGFR3 mutation status.
This study suggest that tumors with FGFR3 mutation appear to have distinctive clinical and biological characteristics that may help in defining a population of patients for FGFR3 mutation screening.
The colon is the most common site for endometriosis outside the genital tract. It has a varied presentation and can mimic numerous other conditions, both clinically and pathologically. We ...investigated the clinicopathological features of a series of colorectal endometriosis with a particular emphasis on the features seen in cases with colonic mucosal involvement. A total of 114 consecutive cases of colorectal endometriosis were reviewed. Forty-eight percent did not have a prior diagnosis of endometriosis and in 34 patients (30%) the endometriosis was determined as the cause for the presentation. Mucosal involvement was present in 31 specimens. Features of chronic colitis were seen in the adjacent mucosa in 90% of cases whilst there were glandular changes mimicking adenocarcinoma in two cases (1.8%). Fifty percent of cases with mucosal involvement also showed glands with a hybrid intestinal-endometrial phenotype by morphology and/or by immunohistochemistry. Endometriosis is an important mimic of other conditions.
Aims
To develop and validate a deep learning algorithm to quantify a broad spectrum of histological features in colorectal carcinoma.
Methods and results
A deep learning algorithm was trained on ...haematoxylin and eosin‐stained slides from tissue microarrays of colorectal carcinomas (N = 230) to segment colorectal carcinoma digitised images into 13 regions and one object. The segmentation algorithm demonstrated moderate to almost perfect agreement with interpretations by gastrointestinal pathologists, and was applied to an independent test cohort of digitised whole slides of colorectal carcinoma (N = 136). The algorithm correctly classified mucinous and high‐grade tumours, and identified significant differences between mismatch repair‐proficient and mismatch repair‐deficient (MMRD) tumours with regard to mucin, inflammatory stroma, and tumour‐infiltrating lymphocytes (TILs). A cutoff of >44.4 TILs per mm2 carcinoma gave a sensitivity of 88% and a specificity of 73% in classifying MMRD carcinomas. Algorithm measures of tumour budding (TB) and poorly differentiated clusters (PDCs) outperformed TB grade derived from routine sign‐out, and compared favourably with manual counts of TB/PDCs with regard to lymphatic, venous and perineural invasion. Comparable associations were seen between algorithm measures of TB/PDCs and manual counts of TB/PDCs for lymph node metastasis (all P < 0.001); however, stronger correlations were seen between the proportion of positive lymph nodes and algorithm measures of TB/PDCs. Stronger associations were also seen between distant metastasis and algorithm measures of TB/PDCs (P = 0.004) than between distant metastasis and TB (P = 0.04) and TB/PDC counts (P = 0.06).
Conclusions
Our results highlight the potential of deep learning to identify and quantify a broad spectrum of histological features in colorectal carcinoma.
The main histologic feature of celiac disease is increased intraepithelial lymphocytes (IELs) with or without villous atrophy of the duodenal mucosa. The aim of this study was to document a broad ...range of additional morphologic changes in intestinal mucosa biopsy specimens from patients with celiac disease. Our cohort comprised 150 patients with positive tissue transglutaminase serologic findings; 7 were at Corazza stage A1, 58 at stage B1, and 85 at stage B2. IEL counts per 100 epithelial cells ranged from 34 to 156 (mean, 88.6); a significant neutrophilic infiltrate was present in 85 cases (56.7%); eosinophil count ranged from 3 to 50 per high-power field (mean, 14.6). Additional findings included morphologic changes in enterocytes in 68.7%, subepithelial collagen thickening in 45.3%, and associated lymphocytic gastritis in 30.4% of patients. We demonstrated that these underrecognized features, which can be misleading, are not uncommon in celiac disease and were positively associated with more advanced stages of the disease (P < .0001).
Background
Secondary carcinoma involving the gastrointestinal (GI) tract is an uncommon finding in biopsy specimens. The diagnosis can be challenging for tumours mimicking a primary carcinoma and ...when the clinical context is unknown.
Methods and results
A multicentre retrospective study was performed to evaluate the clinical and histological features of a series of secondary carcinoma in GI biopsies. A total of 197 cases from 190 patients (median age = 67 years; 57% females) were reviewed. In 16% of patients, the primary carcinoma was unknown. Most lesions presented endoscopically as mucosal or submucosal masses (58%). In 13%, the endoscopy was non‐suspicious for malignancy. The most common tumours were carcinomas of the breast (38%), kidney (13%), lung (12%), prostate (8%) and ovary (7%). The sites of involvement were the stomach (34%), colon (27%), rectum (18%), duodenum (13%), oesophagus (5%), jejunum (3%) and anus (0.5%). Histological patterns of infiltration were mucosal (76%), submucosal (41%), lymphatic (14%), and epithelial colonisation (8%). Submucosal infiltration was found significantly more frequently in carcinomas of the prostate (67%) and lung (62%), compared with carcinomas of the ovary (27%) and breast (23%). Histological obstructive changes were observed in 36% of all cases, with the highest rate in prostate carcinoma (53%) and the lowest rate in kidney carcinoma (8%).
Conclusion
Awareness of the main clinical and histological patterns of secondary carcinomas in GI tract biopsies may help pathologists to raise the possibility of this uncommon diagnosis and confirm it with the judicious use of immunohistochemistry.
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