Expression of cytokeratin 7/20 and Ki67 in Helicobacter pylori-associated gastritis and intestinal metaplasia.

INTRODUCTION: Cytokeratins (CKs) have been associated with precancerous and cancerous gastric lesions in patients with Helicobacter pylori-associated chronic gastritis, making them useful for diagnosing epithelial tumors. METHODOLOGY: A retrospective study was conducted utilizing 200 formalin-fixed paraffin-embedded gastric biopsy samples collected from the lesser curvature of the stomach. Samples from the control group, patients with H. pylori infection, and patients with H. pylori-associated gastritis, with complete and incomplete intestinal metaplasia (IM) were immunostained. Monoclonal antibodies were utilized to determine the expression of CK7, CK20, and Ki-67. RESULTS: Patients infected with H. pylori had strong CK20 expression on the surface, and weak CK7 expression on the surface and deep glands; while non-specific chronic gastritis patients had weak focal CK7 expression and strong CK20 expression. The normal gastric mucosa of patients in the control group had relatively weak CK7 expression, restricted to a few cells in the neck and deep glands. CK20 showed diffuse strong reactivity on the surface. On the other hand, patients with complete IM showed a CK7 staining pattern that was either negative or weakly focal on the surface and crypts associated with diffuse surface CK20 and focal crypt staining corresponding to gastric type IM. The Ki67 proliferating index was low (≤ 15%) in H. pylori infected patients, high (> 30%) in patients with incomplete IM, and intermediate (16-30%) in patients with complete IM. CONCLUSIONS: These results indicate a significant link between the expressions of CK7/CK20 and Ki67 in patients afflicted with H. pylori and IM.

Primary mucinous tumors of the renal pelvis: Clinical, histopathological, and molecular analysis of three cases.

Primary mucinous tumors of the renal pelvis are extremely rare and pose challenges in terms of diagnosis and treatment. This study reviewed the clinical and pathological characteristics of mucinous tumors of the renal pelvis, including mucinous cystadenocarcinomas and mucinous cystadenomas. Immunohistochemical analysis was conducted in three cases, along with KRAS gene detection using the Amplification Refractory Mutation System (ARMS) method. The results revealed mucinous epithelium with acellular mucinous pools in all cases, and acellular mucinous pools were observed in the renal parenchyma and perirenal fat capsules. All tumors expressed CK20 and CDX2, and one case showed KRAS gene mutation. The study suggests that mucinous cystadenomas of the renal pelvis may exhibit borderline biological behaviors. This study is the first to report a KRAS gene mutation in a mucinous cystadenoma of the renal pelvis, offering valuable insights into the diagnosis and treatment of this rare condition.

Enhancing upper tract urothelial carcinoma diagnosis: Utility of cytokeratin 17 and CK20/CD44/p53 immunohistochemical panel.

Upper tract urothelial carcinoma (UTUC) presents diagnostic challenges due to small biopsy specimen size, poor orientation, and technical obstacles that can yield equivocal diagnoses. This uncertainty often mandates repeated biopsies to evaluate the necessity of nephroureterectomy. Prior studies have suggested cytokeratin 17 (CK17) immunostain as an adjunctive tool for diagnosing bladder urothelial neoplasia in both urine cytology and tissue biopsy specimens. We evaluated the utility of CK17 in differentiating UTUC from benign urothelium and its ability to stratify low-grade from high-grade neoplasia. Our study involved a cohort of previously diagnosed cytology (n = 29) and tissue specimens from biopsies and resections (n = 85). We evaluated CK17 staining percentage in cytology and tissue samples and localization patterns in biopsy/resection samples. Our findings showed a statistically significant distinction (p < 0.05) between UTUC and benign tissue specimens based on full thickness localization pattern (odds ratio 8.8 [95% CI 1.53-67.4]). The percentage of CK17 staining failed to significantly differentiate neoplastic from non-neoplastic cases in cytology or tissue samples. Additionally, based on prior research showing the efficacy of CK20/CD44/p53 triple panel in bladder urothelial neoplasia, we utilized tissue microarrays to evaluate if these markers could distinguish UTUC from benign urothelium. We found that CK20/CD44/p53, individually or in combination, could not distinguish urothelial neoplasia from non-neoplasia. Full thickness CK17 urothelial localization by immunohistochemistry was highly reproducible with excellent interobserver agreement and may play a supplementary role in distinguishing upper tract urothelial neoplasia from benign urothelium.

TUMOR MARKERS EXPRESSION LEVELS IN GASTRIC CANCER PATIENT'S PERIPHERAL BLOOD BY RT-PCR ASSESSMENT.

BACKGROUND: Hematological recurrence is the second most frequent cause of failure in the treatment of gastric cancer. The detection of circulating tumor markers in peripheral blood by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) method may be a useful tool to predict recurrence and determine the patient's prognosis. However, no consensus has been reached regarding the association between the tumor markers level in peripheral blood and its impact on patient survival. AIMS: To evaluate the expression of the circulating tumor markers CK20 and MUC1 in peripheral blood samples from patients with gastric cancer by qRT-PCR, and to verify the association of their expression levels with clinicopathological characteristics and survival. METHODS: A total of 31 patients with gastric adenocarcinoma were prospectively included in this study. CK20 and MUC1 expression levels were analyzed from peripheral blood by the qRT-PCR technique. RESULTS: There was no statistically significant (p>0.05) association between CK20 expression levels and clinical, pathological, and surgical features. Higher MUC1 expression levels were associated with female patients (p=0.01). There was a correlation between both gene levels (R=0.81, p<0.001), and CK20 level and tumor size (R=0.39, p=0.034). CONCLUSIONS: CK20 and MUC1 expression levels could be assessed by qRT-PCR from total peripheral blood samples of patients with gastric cancer. CK20 levels were correlated to MUC1 levels as well as to tumor size. There was no difference in disease-free survival and overall survival regarding both genetic markers expression in this series.

Clinical impact of ampulla of Vater cancer subtype classification based on immunohistochemical staining.

BACKGROUND: The histological subtype is an important prognostic factor for ampulla of Vater (AoV) cancer. This study proposes a classification system for the histological subtyping of AoV cancer based on immunohistochemical (IHC) staining and its prognostic significance. METHODS: Seventy-five AoV cancers were analyzed for cytokeratin 7 (CK7), CK20, and causal-type homeobox transcription factor 2 (CDX2) expression by IHC staining. We differentiated the subtypes (INT, intestinal; PB, pancreatobiliary; MIX, mixed; NOS, not otherwise specified) into classification I: CK7/CK20, classification II: CK7/CK20 or CDX2, classification III: CK7/CDX2 and examined their associations with clinicopathological factors. RESULTS: Classifications I, II, and III subtypes were INT (7, 10, and 10 cases), PB (43, 37, and 38 cases), MIX (13, 19, and 18 cases), and NOS (12, 9, and 9 cases). Significant differences in disease-free survival among the subtypes were observed in classifications II and III using CDX2; the PB and NOS subtype exhibited shorter survival time compared with INT subtype. In classification III, an association was revealed between advanced T/N stage, poor differentiation, lymphovascular invasion (LVI), the PB and NOS subtypes, and recurrence risk. In classification III, the subtypes differed significantly in T/N stage and LVI. Patients with the PB subtype had advanced T and N stages and a higher incidence of LVI. CONCLUSIONS: Classification using CDX2 revealed subtypes with distinct prognostic significance. Combining CK7 and CDX2 or adding CDX2 to CK7/CK20 is useful for distinguishing subtypes, predicting disease outcomes, and impacting the clinical management of patients with AoV cancer.

Cytokeratin-20 negative nodal Merkel cell carcinoma with regressed primary: a potential pitfall in interpretation of nodal metastasis.

Merkel cell carcinoma (MCC) is a rare, highly aggressive cutaneous neuroendocrine carcinoma that affects sun-damaged skin. Histologically, the tumor consists of round cells with fine chromatin positive for cytokeratin 20 in ~90% of cases. Rare cases of MCC can regress spontaneously and present as nodal metastasis. Nodal MCC of unknown primary can cause a potential pitfall as they can be misinterpreted as other neuroendocrine carcinomas such as small cell carcinoma. We report a case of nodal MCC with an atypical immunohistochemistry pattern presented as bilateral axillary lymphadenopathy in a 90-year-old man with a remote history of a skin lesion that healed spontaneously leaving a scar.

Cutaneous Metastasis of Transverse Colon Cancer with an Aberrant Pattern of CK7/CK20/CDX2 and High Microsatellite Instability.

A 79-year-old woman was diagnosed with transverse colon cancer, moderately differentiated adenocarcinoma. She underwent surgery and postoperative adjuvant chemotherapy. At 80 years old, the patient exhibited changes in skin tone at the chest and abdomen with CK7+/CK20-/CDX2- immunostaining that was later identified as poorly differentiated adenocarcinoma. The diagnosis was cancer of unknown primary origin. The patient passed away three months after the detection of the skin lesion. Autopsy revealed recurrence at the transverse colon, multiple organ metastases, a similar postmortem immunostaining pattern, and high-frequency microsatellite instability (MSI-high). We herein report this case of CK7+/CK20-/CDX2- and MSI-high transverse colon cancer showing cutaneous metastasis.

Cytokeratin 20 expression is linked to stage progression and to poor prognosis in advanced (pT4) urothelial carcinoma of the bladder.

Cytokeratin 20 (CK20) expression is limited to umbrella cells in the normal urothelium. Since CK20 is often upregulated in neoplastic urothelial cells including dysplasia and carcinoma in situ, immunohistochemical CK20 analysis is often used for the assessment of bladder biopsies. CK20 expression is a feature of luminal bladder cancer subtype, but its prognostic relevance is disputed. In this study, we investigated CK20 on >2700 urothelial bladder carcinomas in a tissue microarray format by immunohistochemistry. Cytoplasmic and membranous CK20 staining was seen in 1319 (51.8%) cancers. The fraction of CK20 positive and especially strongly positive cases increased from pTaG2 low grade (44.5% strongly positive) and pTaG2 high grade (57.7%) to pTaG3 high grade (62.3%; p = 0.0006) but was lower in muscle-invasive (pT2-4) carcinomas (51.1% in all pTa vs. 29.6% in pT2-4; p < 0.0001). Within pT2-4 carcinomas, CK20 positivity was linked to nodal metastasis and lymphatic vessel invasion (p < 0.0001 each) and to venous invasion (p = 0.0177). CK20 staining was unrelated to overall patient survival if all 605 pT2-4 carcinomas were jointly analyzed but subgroup analyses revealed a significant association of CK20 positivity with favorable prognosis in 129 pT4 carcinomas (p = 0.0005). CK20 positivity was strongly linked to the expression of GATA3 (p < 0.0001), another feature of luminal bladder cancer. The combined analysis of both parameters showed best prognosis for luminal A (CK20+/GATA3+, CK20+/GATA3-) and worst outcome for luminal B (CK20-/GATA3+) and basal/squamous (CK20-/GATA3-) in pT4 urothelial carcinomas (p = 0.0005). In summary, the results of our study demonstrate a complex role of CK20 expression in urothelial neoplasms including neoexpression in pTa tumors, a subsequent loss of CK20 expression in a subset of tumors progressing to muscle-invasion, and a stage dependent prognostic role in muscle-invasive cancers.

Clinicopathologic Features and the Loss of ARID1A Expression in Ovarian Seromucinous Borderline Tumors and Seromucinous Carcinomas.

The current study highlighted the ARID1A and SALL4 expression and described histopathologic and immunohistochemical features of ovarian seromucinous tumors (SMTs) including borderline tumors (SMBTs) and seromucinous carcinomas (SMC; namely as endometrioid carcinoma with mucinous differentiation according to WHO 2020 classification). The clinicopathological and immunohistochemical features of 38 SMTs were analyzed, including ARID1A, SALL4, estrogen receptor (ER), progesterone receptor (PR), TP53, keratin 7, keratin 20, CEA, CDX2, WT1, PAX2, and PAX8. SMCs and SMBTs comprised 68.4% (n = 26) and 31.6% (n = 12) of all SMTs, respectively, studied. The mean age of diagnosis was 47.4 years and 41.4 years, and the mean size was 9 cm and 7.45 cm for SMC and SMBT, respectively. There was endometriosis or endometriotic cyst in 61.5% of SMCs and 50% of SMBTs. Immunohistochemically, loss of ARID1A staining was observed in 15 (65.2%) of 26 SMCs, and 3 (33.3%) of the 12 SMBTs. Only one SMC showed focal SALL4 positivity. All SMTs were positive for ER, PR, PAX8, and keratin 7. SMTs were negative for WT1, keratin 20, CDX2, and CEA (negative in 66.7% to 92.3% of the cases). While all SMBTs and 24 (92.3%) of 26 SMCs exhibited "wild-type" TP53 staining, 2 (7.7%) SMCs, both were stage III, showed mutant type TP53 overexpression. We indicate there is a similarity between SMC and SMBT according to the immunohistochemical features. SMBTs are keratin 7, ER, PR positive tumors, and some of them have loss of ARID1A expression and are likely to develop in the background of endometriosis similar to SMC.

Immunohistochemical phenotype of colorectal carcinoma in patients with KRAS mutation and mismatch repair status.

INTRODUCTION: Aberrant expression of CK7/CK20/CDX2 is reported in percentage of colorectal carcinomas (CRC).

A systematic review and meta-analysis of CK20, CD44, Ki67 and p53 as immunohistochemical markers in bladder carcinoma in situ.

BACKGROUND: Urothelial dysplasia and carcinoma in situ (CIS) are related to recurrence and progression of urothelial carcinoma. Differentiating CIS and dysplasia from reactive atypia is often difficult based only on histological features. The integration of histological findings with immunohistochemistry is used in routine practice to make a diagnosis of CIS and, for this purpose, the immunohistochemical markers CK20, CD44, Ki67 and p53 are used to supplement histology. In this work, we aimed to assess CK20, CD44, Ki67 and p53 as immunohistochemical markers in patients with CIS through a systematic review and meta-analysis. MATERIALS AND METHODS: A systematic review was performed by searching electronic databases for English-language studies published from January 2010 to April 2021. Studies were considered eligible if they evaluated the CK20, CD44, Ki67 and p53 expression in CIS. RESULTS: In total, 15 references were suitable for quantitative review. The overall rate of CK20, CD44, Ki67 and p53 expression in CIS was 43%, 31%, 44%, 38%, respectively. CONCLUSIONS: Our study supports the 2014 International Society of Urologic Pathology consensus that histological assessment remains the gold standard to diagnose urothelial CIS and suggests that a very close correlation between morphological, immunohistochemical and clinical data is essential to provide the best management for patients with bladder carcinoma.

Carcinoma of Unknown Primary Origin: Application of Immunohistochemistry With Emphasis to Different Cytokeratin 7 and 20 Staining Patterns.

BACKGROUND: Although the primary origin of some carcinomas may be obscure to clinicians, its identification is crucial as it affects prognosis and treatment (especially novel targeted therapies). Immunohistochemistry (IHC) may be helpful in identifying the primary origin of carcinomas. This retrospective survey aimed to evaluate the frequency and accuracy of each IHC marker used to determine the origin of carcinomas. METHODS: The review of pathology department archives revealed 307 cases of cancer of unknown primary origin (CUP) between 2015 and 2020, which were accessible in the department archives. Demographic information, site of biopsy, clinical and pathologic diagnoses, and IHC results of the patients were collected. RESULTS: The patients included 157 (51.15%) men and 150 (48.85%) women. The age of the patients ranged from 14 to 92 years, including 106 (34.5%) expired cases. In 27% of cases, the primary origin of carcinoma remained unknown. The agreement between pathologic and clinical diagnoses was 59%. The most common pattern of cytokeratin (CK) expression in CUP was CK7+/CK20- (55.3%), followed by CK7-/CK20- (19%), CK7+/CK20+ (15%), and CK7-/CK20+ (10.7%), respectively. CONCLUSION: The IHC analysis may improve the diagnosis of CUPs. However, the origin of some cases remains unknown despite an IHC analysis, thereby necessitating the use of more diagnostic procedures or gene expression studies for reaching a definitive diagnosis.

Xanthomatous Giant Cell Renal Cell Carcinoma: Another Morphologic Form of TSC -associated Renal Cell Carcinoma.

Over the past decade, several distinct novel renal epithelial neoplasms driven by underlying tuberous sclerosis comples ( TSC)/ mammalian target of rapamycin (MTOR) pathway mutations have been described. We report herein two distinctive TSC2 -mutated renal cell carcinomas which do not fit any previously described entity. The two renal carcinomas occurred in young patients (ages 10 and 31 y), and were characterized by highly permeative growth within the kidney with metastases to perirenal lymph nodes. The neoplastic cells were predominantly large, multinucleated giant cells having variably eosinophilic to xanthomatous cytoplasm with basophilic stippling and frequent vacuolization. While the discohesive nature of the neoplastic cells, xanthomatous cytoplasm, immunoreactivity for histiocytic markers and minimal immunoreactivity for conventional epithelial markers raised the possibility of a histiocytic neoplasm, multifocal immunoreactivity for cytokeratin 20 helped establish their epithelial nature. Despite the aggressive growth pattern of these neoplasms and lymph node metastases, mitotic figures were rare and Ki-67 indices were low (<1%). One patient with follow-up shows no evidence of disease seven years after nephrectomy with no adjuvant therapy. Next-generation sequencing demonstrated TSC2 mutations in each case. By immunohistochemistry, downstream markers of mTOR pathway activation S6K1, 4EBP1, and glycoprotein nonmetastatic melanoma protein B were all highly expressed in these neoplasms, suggesting mTOR pathway activation as the neoplastic driver. While the cytokeratin 20 immunoreactivity and focal basophilic cytoplasmic stippling suggest a relationship to eosinophilic solid and cystic renal cell carcinoma, and cytoplasmic vacuolization suggests a relationship to eosinophilic vacuolated tumor, these neoplasms appear to be distinctive given their permeative growth patterns and predominant xanthomatous giant cell morphology. Addition of cytokeratin 20 to a panel of epithelial markers helps avoid misdiagnosis in such cases.

Identifying KRT20 as a Potential Key Gene in Lymphatic Metastasis of Head and Neck Squamous Cell Carcinoma.

Background: Head and neck squamous cell carcinoma (HNSCC) was the seventh most common cancer worldwide in 2018. Lymphatic metastasis (LM) is closely related to HNSCC prognosis and recurrence. However, the underlying mechanism of LM remains unclear. Therefore, this study aimed to identify the key genes in the LM of HNSCC. Methods: We used The Cancer Genome Atlas (TCGA) to identify differentially expressed genes (DEGs) between LM and non-LM cases. A random forest model, the Search Tool for the Retrieval of Interacting Genes, Cytoscape, and cytoHubba were used to identify hub genes among DEGs, including KRT20 (Cytokeratins 20). We analyzed the survival of KRT20 in TCGA, and we overexpressed KRT20 in HNSCC cell lines to investigate its effects on migration and invasion. We also correlated the expression of KRT20 in HNSCC tissue microarrays with survival and clinicopathological features. Results: We identified 243 DEGs-143 upregulated genes and 100 downregulated genes. Further analysis revealed that KRT20 is a potential key gene associated with LM and overall survival rates among patients with HNSCC. Overexpression of KRT20 increased the migration and invasion ability of HNSCC cell lines Tu686 and FD-LSC-1. Tissue microarray studies demonstrated an overexpression of KRT20 among N1+ patients (including N1-N3 patients). Survival analysis results and the clinicopathological features of HNSCC tissue microarrays were consistent with our analysis of TCGA. Thus, a high KRT20 expression level might suggest an adverse HNSCC prognosis. Our gene set enrichment analysis showed that KRT20 participates in many metabolic pathways, including those related to tumorigenesis and cancer development. Conclusions: We propose that KRT20 may be a key gene in HNSCC with LM.

Significance of Intraperitoneal-free KRT20 and CEACAM6 mRNA Expression for Peritoneal Recurrence of Gastric Cancer.

BACKGROUND/AIM: Peritoneal lavage cytology is widely used to predict peritoneal recurrence after surgery, but cases of peritoneal recurrence are often recognized in patients with peritoneal lavage cytology negativity (CY0) who underwent no residual tumour (R0) surgery. We used peritoneal lavage fluid before and after gastric cancer surgery to detect cytokeratin 20 (KRT20) and carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) mRNA by RT-PCR. MATERIALS AND METHODS: We collected peritoneal lavage fluid before and after surgery from 58 patients who underwent gastrectomy. RNA was extracted from these samples and RT-PCR was performed. RNA expression was defined as positive and negative in cases with values higher or lower than the median value. We investigated the relationship between mRNA expression and clinicopathological and surgical factors and prognosis. RESULTS: Tumour invasion to the sub-serosa (T3) or penetration of the serosa (T4a), lymph node metastasis, and more than 150 ml intraoperative bleeding were significantly correlated with KRT20 mRNA expression. Multivariate analysis of its relationship with peritoneal recurrence showed that the odds ratio of CEACAM6 mRNA for recurrence was high (odds ratio=24.753; 95%CI=0.883-694.06; p=0.0592). All cases with peritoneal recurrence were CEACAM6-positive at pre- or post-surgery. The prognosis of peritoneal recurrence for both KRT20- and CEACAM6-positive cases was significantly poorer than that of other cases. The recurrence-free survival of the CEACAM6-positive group was significantly poorer than that of the CEACAM6-negative group. CONCLUSION: Measurement of CEACAM6 mRNA in peritoneal lavage fluid at pre- and post-surgery may be useful as a predictor of peritoneal recurrence.

Determining the relationship between cytokeratin expression and prognostic factors in human gastric cancer.

Determining the prognosis of gastric cancer is the most crucial step in the treatment process. Cytokeratins are intermediate filaments found in the intracellular structure of epithelial tissues. Recent researches have focused on determining the relationship between the expression of cytokeratins and the degree and prognosis of tumors. This study aimed to investigate the relationship between the incidence of cytokeratin-20 and cytokeratin-7 in patients with gastric carcinoma with factors influencing the prognosis. In this regard, the study was conducted cross-sectional. The expression of cytokeratin-20 and cytokeratin-7 was evaluated on 50 gastric adenocarcinoma specimens with different degrees of differentiation by the immunohistochemical method. We determined the relationship between the incidence of cytokeratin-20 and cytokeratin-7 with factors affecting the prognosis of patients, including the degree of differentiation of gastric cancer tissue, lymph node involvement, and the depth of tumor invasion. Data were statistically analyzed by Chi-square and Spearman tests. The results showed a statistically inverse relationship between the incidence of cytokeratin-20 and cytokeratin-7 with the degree of tissue differentiation and lymph node involvement in gastric cancer. Although there was a statistically significant relationship between the incidence of tissue invasion in gastric cancer and the incidence of cytokeratin-7, there was no association between the incidence of cytokeratin-20 and tissue invasion. In general, decreased cytokeratin-20 and cytokeratin-7 are associated with decreased tissue differentiation and increased lymph node involvement.

Immunohistochemical expression of CK20, CK7, and CDX2 in colorectal carcinoma in correlation with pathomorphological characteristics.

INTRODUCTION: Colorectal carcinoma is the third most common cancer worldwide. The usual immunophenotype of colorectal adenocarcinoma is CDX2 positive, CK20 positive, and CK7 negative. Aberrant expression is reported in a variety of colorectal carcinomas but its relation to morphological variables and survival data is still unclear.

Could double stain for p53/CK20 be a useful diagnostic tool for the appropriate classification of flat urothelial lesions?

BACKGROUND: The differential diagnosis between flat urothelial lesions [reactive urothelial atypia (RUA), atypia of unknown significance (AUS), urothelial dysplasia (UD) and carcinoma in situ (CIS)] has relevant prognostic and therapeutic implications. This crucial distinction could be very challenging but it is currently performed on hematoxylin and eosin (H&E) slides, with a great amount of partially discordant and/or not conclusive findings of the potential adjunctive role of immunohistochemistry. Herein, we tested double staining (DS) for p53/CK20 to verify if p53(+) cells, CK20(+) cells and double-positive cells (DPCs) are differentially expressed among these lesions and if p53/CK20 could be a useful tool in this diagnostic setting. METHODS: We tested 50, 9, 36 and 29 consecutive and retrospectively enrolled cases of RUA, AUS, UD and CIS, respectively. p53(+) cells, CK20(+) cells and DPCs were evaluated and compared by adopting the appropriate statistic tests (Mann-Whitney U and Kruskal-Wallis tests). RESULTS: We found that p53(+) cells (p = 0.000), CK20(+) cells (p = 0.000) and DPCs (p = 0.000) showed statistically significant differences among the different flat urothelial lesions. Besides, when dichotomized, both CIS and RUA are easily differentiable from their histological mimickers adopting all these markers; by contrast, AUS and UD did not reach statistically significant differences able to differentiate them from each other [p53(+) cells, p = 0.123; CK20(+) cells, p = 0.567; DPCs, p = 0.409], except if compared to CIS [AUS VS CIS: p53(+) cells, p = 0.013; CK20(+) cells, p = 0.000; DPCs, p = 0.000; UD vs CIS: p53(+) cells, p = 0.000; CK20(+) cells, p = 0.000; DPCs, p = 0.000]. CONCLUSIONS: p53(+) cells, CK20(+) cells and DPCs are differently expressed by flat urothelial lesions and p53/CK20 could be a time- and money-saving tool for the appropriate management of these lesions if applied to a routine scenario.

Robotic low anterior resection of rectal metastasis from small bowel adenocarcinoma: A case report.

A 69-year-old female underwent laparoscopic ileal partial resection for ileal adenocarcinoma. Pathological diagnosis was moderately differentiated tubular adenocarcinoma (UICC 8th; T4N0M0 StageIIB). The patient received adjuvant chemotherapy with modified 5-fluorouracil/leucovorin/oxaliplatin. Fourteen months after surgery, computed tomography revealed a mass in the upper rectum. Colonoscopy detected a submucosal protruding mass and a biopsy specimen showed moderately differentiated tubular adenocarcinoma. Robotic low anterior resection was performed. The tumor was located in the upper rectum and there was no macroscopic invasion or peritoneal dissemination. Pathologically, the tumor was moderately differentiated tubular adenocarcinoma located within the rectal wall with little evidence of a carcinoma component in the mucosal lining. Immunohistochemistry showed the same pattern as the previous ileal adenocarcinoma: negativity for cytokeratin 7 and positivity for cytokeratin 20 and caudal-type homeobox 2. In combination with the rectum showing no abnormalities in colonoscopy performed 15 mo previously, the mass was considered hematogenous metastasis from small bowel adenocarcinoma.

Cytokeratin 7 and cytokeratin 20 expression in cancer: A tissue microarray study on 15,424 cancers.

Combined analysis of cytokeratin 7 (CK7) and cytokeratin 20 (CK20) is often used for assessing the origin of metastatic cancer. To evaluate the diagnostic utility of CK7 and CK20, tissue microarrays containing 15,424 samples from 120 different tumor types and subtypes and 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry. CK7 positivity was seen in 52% (8.7% weak, 5.9% moderate, 37% strong) and CK20 positivity in 23% (5.1% weak, 3.4% moderate, 15% strong) of interpretable tumors. Of 8390 positive tumors, 1181 (14%) showed positivity for CK7 and CK20, 5380 (64%) showed positivity for CK7 alone, and 1829 (22%) showed positivity for CK20 alone. CK20 predominated in gastrointestinal tract, urothelial and Merkel cell carcinomas. CK7 was usually negative in prostate cancer and colorectal cancer. Combined evaluation of CK7/CK20 revealed the best diagnostic utility in CK20 positive tumors, where CK7 negativity is often linked to colorectal origin while CK7 positivity argues for urothelial origin or mucinous ovarian cancer. Associations with unfavorable tumor features were found for cytokeratin 7 loss in breast cancer of no special type, urothelial and renal cell carcinomas, for CK7 overexpression in high-grade serous ovarian and gastric cancer, and for CK20 overexpression in urothelial carcinoma. CK20 loss was linked to MSI in gastric (p = 0.0291) and colorectal adenocarcinoma (p < 0.0001). These analyses provide comprehensive data on the frequency of CK7 and CK20 immunostaining - alone or in combination - in human cancers. These data facilitate interpretation of CK7/CK20 immunostaining in cancers.