The value of CDX2 and cytokeratins 7 and 20 expression in differentiating colorectal adenocarcinomas from extraintestinal gastrointestinal adenocarcinomas: cytokeratin 7-/20+ phenotype is more specific than CDX2 antibody

Primary Mucinous Adenocarcinoma of the Renal Pelvis: A Case Report

Mucinous adenocarcinomas of the upper urinary tract are extremely rare, and the majority of information available comes from case reports or short case series. Intestinal metaplasia is considered a premalignant condition in carcinogenesis. Here we present a case of a 55-year-old male who presented with a left flank mass extending to the left hemiabdomen and macroscopic hematuria. Pathologic findings revealed that the kidney was transformed into a multiloculated cystic mass measuring 18 × 12 × 11 cm, with a dilated pelvicalyceal system obstructed by a stone at the renal hilus and filled with a gray, soft, gelatinous material. Histopathologic sections showed glandular metaplasia of the proximal ureter ascending to the renal pelvis, lined by intestinal-type columnar epithelium containing goblet cells admixed with malignant glands floating in abundant extracellular mucin, along with poorly differentiated areas composed of signet ring cells. Immunohistochemistry studies showed positive periodic acid Schiff (PAS)/periodic acid Schiff-diastase (PAS-D), consistent with the mucinous nature of the intracellular and extracellular materials. Positive immunohistochemical staining for CK7, CK20, and CDX2 (CK7+/CK20+/CDX2+) highlighted the intestinal differentiation of this neoplasm. This offers evidence for the intestinal metaplasia-dysplasia-carcinoma sequence rather than a teratomatous or coelomic epithelial origin in mucinous ovarian-like cystadenocarcinoma involving the renal pelvis.

Evaluation of the Immunohistochemical Scoring System of CDX2 Expression as a Prognostic Biomarker in Colon Cancer

Encoded by the CDX2 homeobox gene, the CDX2 protein assumes the role of a pivotal transcription factor localized within the nucleus of intestinal epithelial cells, orchestrating the delicate equilibrium of intestinal physiology while intricately guiding the precise development and differentiation of epithelial tissue. Emerging research has unveiled that positive immunohistochemical expression of this protein shows that the CDX2 gene exerts a potent suppressive impact on tumor advancement in colorectal cancer, impeding the proliferation and distant dissemination of tumor cells, while the inhibition or suppression of CDX2 frequently correlates with aggressive behavior in colorectal cancer. In this study, we conducted an immunohistochemical assessment of CDX2 expression on a cohort of 43 intraoperatively obtained tumor specimens from patients diagnosed with colon cancer at Colțea Clinical Hospital in Bucharest, between April 2019 and December 2023. Additionally, we shed light on the morphological diversity within colon tumors, uncovering varying differentiation grades within the same tumor, reflecting the variations in CDX2 expression as well as the genetic complexity underlying these tumors. Based on the findings, we developed an innovative immunohistochemical scoring system that addresses the heterogeneous nature of colon tumors. Comprehensive statistical analysis of CDX2 immunohistochemical expression unveiled significant correlations with known histopathological parameters such as tumor differentiation grades (p-value = 0.011) and tumor budding score (p-value = 0.002), providing intriguing insights into the complex involvement of the CDX2 gene in orchestrating tumor progression through modulation of differentiation processes, and highlighting its role in metastatic predisposition. The compelling correlation identified between CDX2 expression and conventional histopathological parameters emphasizes the prognostic significance of the CDX2 biomarker in colon cancer. Moreover, our novel immunohistochemical scoring system reveals a distinct subset of colon tumors exhibiting reserved prognostic outcomes, distinguished by their "mosaic" CDX2 expression pattern.

A Somatic BRCA2-Mutated Pancreatic Adenocarcinoma With Sustained Exceptional Response to Modified FOLFIRINOX

Homologous recombination repair (HRR) pathway deficiency opens multiple therapeutic avenues within pancreatic cancer. Patients with HRR deficiency-associated gene mutations such as BRCA1, BRCA2, and PALB2 are more susceptible to platinum-based chemotherapies and in those with somatic BRCA mutations, PARP inhibitor therapy prolongs progression-free survival. The case discussed herein illustrates the therapeutic opportunities offered through the identification of HRR deficiency in pancreatic cancer, as well as the challenges associated with treatment and prevention of central nervous system metastases in long-term survivors of pancreatic cancer.

High KRT17 expression in tumour budding indicates immunologically 'hot' tumour budding and predicts good survival in patients with colorectal cancer

Objectives

Emerging evidence has demonstrated that tumour budding (TB) is negatively associated with T-lymphocyte infiltration in CRC. Despite extensive research, the molecular characteristics of immunologically 'hot' TB remain poorly understood.

Methods

We quantified the number of TB by haematoxylin-eosin (H&E) sections and the densities of CD3+ and CD8+ T-lymphocytes by immunohistochemistry in a CRC cohort of 351 cases who underwent curative resection. We analysed the differential expression and T-lymphocyte infiltration score of 37 human epithelial keratins in CRC using RNA sequencing from the TCGA dataset. In 278 TB-positive cases, KRT17 expression was evaluated in tumour centre (TC) and TB with a staining score. Patient demographic, clinicopathological features and survival rates were analysed.

Results

In a CRC cohort of 351 cases, low-grade TB was associated with high CD3+ and CD8+ T-cell densities in the invasive margin (IM) but not in the TC. Of 37 human epithelial keratins, only KRT17 expression in TB had an apparent association with TB-grade and T-lymphocyte infiltration. In 278 TB-positive cases, high KRT17 expression in TB (KRT17TB) was negatively associated with low-grade TB and positively associated with high CD3+ and CD8+ T-cell densities in IM. High KRT17TB predicted early tumour grade, absence of lymph node metastasis and absence of tumour deposits. Additionally, patients with high KRT17TB had good overall survival and disease-free survival. Notably, low KRT17TB can specifically identify those patients with a poor prognosis among colorectal cancer patients with low TB and high T-lymphocyte infiltration.

Conclusions

KRT17 can be employed as a new indicator for distinguishing different immunological TBs.

Metastatic gastric adenocarcinoma to the cutaneous neck and chest wall

This case describes an atypical cutaneous presentation of metastatic gastric carcinoma in a patient initially presenting with dysphagia and a sclerotic red plaque overlying the anterior neck and chest. Skin biopsy revealed metastatic adenocarcinoma from the upper gastrointestinal tract. Esophagogastroduodenoscopy revealed stage IV metastatic gastric adenocarcinoma. Treatment with chemotherapy was initiated.

Primary Serous Cystadenocarcinoma of the Spleen

Tumours of the spleen are uncommon, and most are metastases from primaries in other organs. Primary splenic malignancies are subdivided into two main groups: lymphoid and non-lymphoid. Primary splenic cystadenocarcinomas are extremely rare, and only reports of the mucinous variant exist. We present the case of a female in her eighth decade of life who was found to have an incidental complex splenic mass with a cystic component, which showed an interval increase in size on serial imaging. After further investigation, including positron emission tomography (PET), endoscopic ultrasound (EUS), and laparoscopy, she successfully underwent distal pancreatectomy, splenectomy, and partial gastrectomy for a suspected locally invasive pancreatic malignancy. Histology and immunohistochemical analyses were consistent with the first recorded case of primary serous cystadenocarcinoma of the spleen in the literature.

Quantitative mRNA expression measurement at home

mRNA measurement is dominated by RT-PCR, which requires expensive laboratory equipment and personnel with advanced degrees. Loop-mediated isothermal amplification (LAMP) is a versatile technique for detecting target DNA and RNA. The sensitivity of LAMP in early reports has been below that of the standard RT-PCR tests. Here, we report the use of a fluorescence-based RT-LAMP protocol to measure CDX2 expression patterns, which match extremely well to the standards of sophisticated RT-PCR techniques (r = 0.99, p < 0.001). The assay works on diverse sample types such as cDNA, mRNA, and direct tissue sample testing in 25 min compared to more than 3 h for RT-PCR. We have developed a new protocol for designing RT-LAMP primers that reduce false positives due to self-amplification and improve quantification. A simple device with a 3D-printed box enables the measurement of mRNA expression at home, outdoors, and point-of-care setting.

A novel frameshift mutation of the endoglin(ENG) gene causes hereditary hemorrhagic telangiectasia in a Chinese family

PURPOSE

Hereditary hemorrhagic telangiectasia (HHT) is a dominantly inherited disorder that involves epistaxis, mucocutaneous telangiectases, and visceral arteriovenous malformations (AVMs). This study aims to investigate the genetic causes in a Chinese family with HHT.

METHODS

HHT was confirmed according to Curaçao's diagnostic criteria. Three patients diagnosed with HHT and healthy members were recruited. Whole-exome sequencing (WES) and sanger sequencing were performed to define the patient's genetically pathogenic factor.

RESULTS

The proband presented with recurrent epistaxis, hepatopulmonary arteriovenous malformation, and adenocarcinoma. A novel frameshift mutation (c.1376_1377delAC, p.H459Lfs*41) of the ENG gene was revealed in affected individuals by WES. There was no report of this variant and predicted to be highly damaging by causing truncation of the ENG protein.

CONCLUSION

We report a novel variant in the ENG gene in Chinese that extends the mutational and phenotypic spectra of the ENG gene, and also demonstrates the feasibility of WES in the application of genetic diagnosis of HHT.

Case Report: Recurrent colonic metastasis from lung cancer-diagnostic pitfalls and therapeutic challenge of a peculiar case

Lung cancer (LC) mortality exceeds 20%, and detecting metastases from LC is becoming a challenging step in understanding the real prognostic role of specific localization. We report a case of a patient with lung metastasis to the colon with local recurrence at the anastomosis after radical resection for metastasis. In both cases, the diagnosis was on oncological follow-up, and surgery was offered in consideration of reasonable life expectancy, good control of LC, and high risk of intestinal occlusion. A 67-year-old male, with a history of LC 18 months ago, was referred to our surgical unit after a positron emission tomography CT total body, where an area of intense glucose metabolism (SUV max: 35.6) at the hepatic colic flexure was reported. A colonoscopy revealed an ulcerated, bleeding large neoplasm distally to hepatic flexure, almost causing resulting total occlusion. Histologic examination revealed a tumor with complete wall thickness infiltration, which appears extensively ulcerated, from poorly differentiated squamous carcinoma (G3), not keratinizing, with growth in large solid nests, often centered by central necrosis. Two of the 30 isolated lymph nodes were metastatic. The omental flap and resection margins were free from infiltration. The malignant cells exhibited strong positive immunoreactivity only for p40. The features supported metastatic squamous carcinoma of lung origin rather than primary colorectal adenocarcinoma. After 8 months from surgery, intense Fluorodeoxyglucose (FDG) uptake of tissue was confirmed in the transverse colon. Colonoscopy evidenced an ulcerated substenotic area that involved ileocolic anastomosis on both sides. Reoperation consisted of radical resection of ileocolic anastomosis with local lymphadenectomy and ileotransverse anastomosis. The second histologic examination also revealed poorly differentiated squamous carcinoma (G3), not keratinizing, with positive immunoreactivity only for p40, suggesting the origin of LC. This case report confirmed that the possibility of colonic secondary disease should be part of the differential diagnosis in asymptomatic patients and those with a history of LC diagnosis. In addition, relapse of colonic metastasis is infrequent but should be considered during follow-up of LC. More studies on colonic metastasis of LC are required to better understand the clinical features and outcomes.

Development of a Genetically Engineered Mouse Model Recapitulating LKB1 and PTEN Deficiency in Gastric Cancer Pathogenesis

The LKB1 and PTEN genes are critical in gastric cancer (G.C.) development. LKB1, a robust tumor suppressor gene, encodes a serine/threonine kinase that directly triggers the activation of AMPK-an integral cellular metabolic kinase. The role of the LKB1 pathway extends to maintaining the stability of epithelial junctions by regulating E-cadherin expression. Conversely, PTEN, a frequently mutated tumor suppressor gene in various human cancers, emerges as a pivotal negative regulator of the phosphoinositide 3-kinase (PI3K) signaling pathway. This study is set to leverage the H+/K+ ATPase Cre transgene strain to precisely target Cre recombinase expression at parietal cells within the stomach. This strategic maneuver seeks to selectively nullify the functions of both LKB1 and PTEN in a manner specific to the stomach, thereby instigating the development of G.C. in a fashion akin to human gastric adenocarcinoma. Moreover, this study endeavors to dissect the intricate ways in which these alterations contribute to the histopathologic advancement of gastric tumors, their potential for invasiveness and metastasis, their angiogenesis, and the evolving tumor stromal microenvironment. Our results show that conditional deletion of PTEN and LKB1 provides an ideal cancer microenvironment for G.C. tumorigenesis by promoting cancer cell proliferation, angiogenesis, and metastasis.

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.

Long-Term Oncological Control by Repeated Minimally Invasive Hepatectomy for Intrahepatic Cholangiocarcinoma Exhibiting Atypical Marker Expression of CK7-CK20+: A Case Report

There are few reports of repeated liver resections being performed multiple times for intrahepatic recurrence of intrahepatic cholangiocarcinoma (ICC). We performed five minimally invasive liver resections and two minimally invasive lung resections for ICC with metachronous intrahepatic recurrence and lung metastases. Pathological examination revealed that all resected tumors were moderately differentiated mass-forming ICC with immunohistochemical marker expression of CK7 negative and CK20 positive. We present this as a rare case of ICC with atypical marker expression in which long-term tumor control was achieved with multiple minimally invasive liver resections over 47 months from the initial diagnosis.

Deep Learning-Enabled Diagnosis of Liver Adenocarcinoma

BACKGROUND & AIMS

Diagnosis of adenocarcinoma in the liver is a frequent scenario in routine pathology and has a critical impact on clinical decision making. However, rendering a correct diagnosis can be challenging, and often requires the integration of clinical, radiologic, and immunohistochemical information. We present a deep learning model (HEPNET) to distinguish intrahepatic cholangiocarcinoma from colorectal liver metastasis, as the most frequent primary and secondary forms of liver adenocarcinoma, with clinical grade accuracy using H&E-stained whole-slide images.

METHODS

HEPNET was trained on 714,589 image tiles from 456 patients who were randomly selected in a stratified manner from a pool of 571 patients who underwent surgical resection or biopsy at Heidelberg University Hospital. Model performance was evaluated on a hold-out internal test set comprising 115 patients and externally validated on 159 patients recruited at Mainz University Hospital.

RESULTS

On the hold-out internal test set, HEPNET achieved an area under the receiver operating characteristic curve of 0.994 (95% CI, 0.989-1.000) and an accuracy of 96.522% (95% CI, 94.521%-98.694%) at the patient level. Validation on the external test set yielded an area under the receiver operating characteristic curve of 0.997 (95% CI, 0.995-1.000), corresponding to an accuracy of 98.113% (95% CI, 96.907%-100.000%). HEPNET surpassed the performance of 6 pathology experts with different levels of experience in a reader study of 50 patients (P = .0005), boosted the performance of resident pathologists to the level of senior pathologists, and reduced potential downstream analyses.

CONCLUSIONS

We provided a ready-to-use tool with clinical grade performance that may facilitate routine pathology by rendering a definitive diagnosis and guiding ancillary testing. The incorporation of HEPNET into pathology laboratories may optimize the diagnostic workflow, complemented by test-related labor and cost savings.

An Early-Stage Colon Cancer Develops Intrabiliary Growth Type Metastasis 7 Years After Curative Colectomy

Although liver metastasis commonly occurs in patients with colorectal cancer (CRC), it is infrequent that it presents several years after curative resection for early-stage disease. Even more unusual is development of intrabiliary growth type metastasis rather than parenchymal metastasis. When this occurs, it can be mistaken for cholangiocarcinoma. We present a case in a patient with history of pT1N0M0 CRC treated with sigmoidectomy 7 years previously who presented with abdominal pain and MRI revealing left hepatic ductal dilation with no accompanying mass. With a recent normal colonoscopy and carcinoembryonic antigen, he was diagnosed with cholangiocarcinoma. Anatomic hepatic resection was performed, and final pathology with immunohistochemistry revealed staining consistent with CRC metastasis rather than cholangiocarcinoma. Intrabiliary growth type metastasis is a rare occurrence, which leads to its misdiagnosis. Patients with an intrabiliary tumor and a history of CRC should have immunohistochemistry to confirm the diagnosis to ensure appropriate adjuvant treatment and counseling.

A rare case of esophageal metastasis from signet-ring cell carcinoma of the cecum

BACKGROUND

Metastatic esophageal cancer is rare. Its common primary lesions include lung cancer and breast cancer. Metastatic esophageal cancer originating from colorectal cancer is rarer.

CASE PRESENTATION

A 79-year-old woman visited our hospital because of lower abdominal discomfort. She was endoscopically diagnosed with type 0-IIa + IIc cancer of the cecum, and biopsy of the lesion showed signet-ring cell carcinoma. With a preoperative clinical staging of cStage I (cT2, cN0, cM0), the patient underwent laparoscopic ileocecal resection with D3 lymphadenectomy. Histopathological examination of the resected specimens revealed signet-ring cell carcinoma [type 4, pT4a, pN3 (No. 203), M0, pRM1, stage IIIc, R1]. Despite radial margin positivity, the patient refused resection of the residual tumor and received oral tegafur and uracil. KRAS mutation test showed KRAS wild-type colon cancer, but she refused anti-epidermal growth factor receptor therapy. One year after surgery, her blood carcinoembryonic antigen concentration elevated. Colonoscopy showed anastomotic recurrence and biopsy of the lesion showed signet-ring cell carcinoma. Upper gastrointestinal endoscopy showed multiple longitudinal submucosal tumors with erosions on their surfaces in the esophagus. Tumor biopsy revealed signet-ring cell carcinoma. Immunohistochemistry showed that the histological type of the esophageal tumors was the same as that of the primary colon cancer. Based on these findings, the esophageal tumors were diagnosed with metastasis from signet-ring cell carcinoma of the cecum. The oral chemotherapy was replaced with FOLFOX plus bevacizumab. However, the patient's condition required treatment discontinuation, and she died of cancer progression 1 year and 5 months after surgery.

CONCLUSIONS

To our knowledge, this is the first case report on metastatic esophageal cancer from signet-ring cell carcinoma of the cecum. Esophagoscopy showed multiple longitudinal submucosal tumors, which is similar to an endoscopic finding of intramural metastasis from primary esophageal cancer. We consider that the multiple longitudinal submucosal tumors are a notable feature of our case. When metastatic esophageal cancer is suspected, clinicians, endoscopists, and pathologists should consider signet-ring cell carcinoma of the colon as one of potential primary lesions. This consideration could lead the specialists to appropriate examinations and treatments, thereby improving clinical outcomes in patients with the metastasis.

The EMT factor ZEB1 paradoxically inhibits EMT in BRAF-mutant carcinomas

Despite being in the same pathway, mutations of KRAS and BRAF in colorectal carcinomas (CRCs) determine distinct progression courses. ZEB1 induces an epithelial-to-mesenchymal transition (EMT) and is associated with worse progression in most carcinomas. Using samples from patients with CRC, mouse models of KrasG12D and BrafV600E CRC, and a Zeb1-deficient mouse, we show that ZEB1 had opposite functions in KRAS- and BRAF-mutant CRCs. In KrasG12D CRCs, ZEB1 was correlated with a worse prognosis and a higher number of larger and undifferentiated (mesenchymal or EMT-like) tumors. Surprisingly, in BrafV600E CRC, ZEB1 was associated with better prognosis; fewer, smaller, and more differentiated (reduced EMT) primary tumors; and fewer metastases. ZEB1 was positively correlated in KRAS-mutant CRC cells and negatively in BRAF-mutant CRC cells with gene signatures for EMT, cell proliferation and survival, and ERK signaling. On a mechanistic level, ZEB1 knockdown in KRAS-mutant CRC cells increased apoptosis and reduced clonogenicity and anchorage-independent growth; the reverse occurred in BRAFV600E CRC cells. ZEB1 is associated with better prognosis and reduced EMT signature in patients harboring BRAF CRCs. These data suggest that ZEB1 can function as a tumor suppressor in BRAF-mutant CRCs, highlighting the importance of considering the KRAS/BRAF mutational background of CRCs in therapeutic strategies targeting ZEB1/EMT.

Predictive Potential of Biomarkers of Intestinal Barrier Function for Therapeutic Management with Teduglutide in Patients with Short Bowel Syndrome

INTRODUCTION

The human intestinal tract reacts to extensive resection with spontaneous intestinal adaptation. We analyzed whether gene expression analyses or intestinal permeability (IP) testing could provide biomarkers to describe regulation mechanisms in the intestinal barrier in short bowel syndrome (SBS) patients during adaptive response or treatment with the glucagon-like peptide-2 analog teduglutide.

METHODS

Relevant regions of the GLP-2 receptor gene were sequenced. Gene expression analyses and immunohistochemistry were performed from mucosal biopsies. IP was assessed using a carbohydrate oral ingestion test.

RESULTS

The study includes 59 SBS patients and 19 controls. Increases in gene expression with teduglutide were received for sucrase-isomaltase, sodium/glucose cotransporter 1, and calcium/calmodulin serine protein kinase. Mannitol recovery was decreased in SBS but elevated with teduglutide (Δ 40%), showed a positive correlation with remnant small bowel and an inverse correlation with parenteral support.

CONCLUSIONS

Biomarkers predicting clinical and functional features in human SBS are very limited. Altered specific gene expression was shown for genes involved in nutrient transport but not for genes controlling tight junctions. However, mannitol recovery proved useful in describing the absorptive capacity of the gut during adaptation and treatment with teduglutide.

The first case report of metastatic rectal adenocarcinoma to the oral vestibule in a young woman

BACKGROUND

The available literature regarding metastasis to the oral cavity from colorectal cancer, especially rectal cancer, is currently limited. With this in mind, we aimed to report the first case of rectal adenocarcinoma metastasis to the oral vestibule.

CASE REPORT

A 36-year-old Caucasian female with a 17-months history of rectal adenocarcinoma and several metastases was referred to the Dental Oncology Service due to a nodular swelling in the oral cavity. Intraoral examination showed a large, painless nodule with superficial necrosis on the right side of the mandibular vestibule. An incisional biopsy was performed, and the microscopic analysis demonstrated an infiltrative tumor characterized by islands of malignant epithelial cells with a columnar appearance and tubular pattern. The epithelial component presented pseudoductal structures resemble intestinal mucosa, which exhibited intraluminal secretion. The neoplastic cells were immunoreactive for CDX2 and Cytokeratin 20, and negative for Cytokeratin 7. Therefore, the final diagnosis of metastatic rectal adenocarcinoma was established. Unfortunately, the patient died 23 months after the diagnosis of the primary tumor.

CONCLUSION

The study highlights that metastases to the oral cavity should be considered in the differential diagnosis of large reactive lesions affecting young patients, especially in the setting of a patient history of cancer.

The Role of Immunohistochemistry in the Differential Diagnosis between Intrahepatic Cholangiocarcinoma, Hepatocellular Carcinoma and Liver Metastasis, as Well as Its Prognostic Value

Intrahepatic cholangiocarcinoma (iCCA) is the second most frequent primary hepatic malignant tumor, after hepatocellular carcinoma (HCC). Its incidence has risen worldwide, yet the only potentially curative treatment, surgical resection, is seldom applicable, and the median overall survival remains extremely low. So far, there are no personalized therapy regimens. This study investigated whether routine immunohistochemical stains have diagnostic and/or prognostic value in iCCA. Clinical, imaging, and pathology data were retrospectively gathered for patients diagnosed with iCCA, HCC, or liver metastases assessed using liver needle biopsies. Three study groups with an equal number of cases (n = 65) were formed. In the iCCA group, CK19, CA19-9, CK7, and CEA demonstrated the highest sensitivities (100%, 100%, 93.7%, and 82.6%, respectively). The most relevant stains used for diagnosing HCCs were Glypican 3, CD34 (sinusoidal pattern), and Hep Par 1, with corresponding sensitivities of 100%, 100%, and 98.2%. The immunohistochemical panels for diagnosing metastatic tumors were chosen after correlating the clinical data and morphologic H&E aspects. Moderate/intensely positive CK7 expression and absent/low amount of intratumoral immune cells were favorable prognostic factors and correlated with increased overall survival in both the univariate analysis and the multivariate regression adjusted for age, existence of cirrhosis, number of tumors, and tumor differentiation.

Immunoexpression of CDX2 in metastatic nonintestinal adenocarcinomas: an immunohistochemical pitfall and its pathological implications

Background

CDX2, a homeobox gene is the marker of intestinal differentiation. Its expression may lead to misdiagnosis while evaluating metastasis from unknown primary. In the present narrative, we discuss the clinical, morphological, and immunohistochemical (IHC) findings of metastatic adenocarcinoma of the lymph node that displayed nuclear immunoexpression of CDX2. However, the clinical and radiological picture supported the non-intestinal primary; prostate in one and lung in the other.

Case presentation

A 68-year-old man presented cervical lymph node enlargement. An epithelial tumor with acinar and cribriform pattern was seen that showed expression of CK, CDX2, and PSA in IHC. The patients complained of nonspecific symptoms related to both the gastrointestinal system and the prostate. Serum PSA was diagnostic (> 500 ng/ml). Similarly, core biopsy from mediastinal lymph node from a 51-year-male was received with possible differential of cancer and tuberculosis. Moderately differentiated adenocarcinoma was observed with the expression of EMA, CK 7, CDX2, and TTF1. The expression of both CDX2 and TTF1 was patchy. When the patient was called and all the details were sought the computed tomography (CT) thorax showed a lower chest wall lesion and multiple metastasis. The case was hence signed off as primary from lung on basis of clinical picture.

Conclusion

Such deviants must be reported and recorded. The knowledge of these will make a pathologist cautious and thus avoid misdiagnosis.

Concurrent Splenic Marginal Zone B Cell Lymphoma and Metastatic Pancreatic Adenocarcinoma Diagnosed on Splenectomy for Suspected Splenic Abscess

Splenic marginal zone lymphoma (SMZL) is an uncommon low-grade B-cell lymphoma. It is an indolent lymphoma with a median survival rate of greater than 10 years. Most patients are asymptomatic, but some patients may present with upper abdominal pain and distention, while others may present with splenomegaly, emaciation, fatigue, or weight loss. Due to the long median survival, patients with SMZL may develop a second primary malignancy. Pancreatic adenocarcinoma is the most common malignant neoplasm of the pancreas. It has a poor prognosis with a five-year survival rate of 10%. Fifty percent of patients have metastatic disease on presentation. However, the spleen is not a common site of metastasis for malignant tumors from other primary sites including the pancreas. Here we present a case of a 78-year-old African American patient, who was found to have previously undiagnosed, concurrent metastatic pancreatic adenocarcinoma and SMZL diagnosed on splenectomy for a suspected splenic abscess.

A review of 14 cases of perianal Paget's disease: characteristics of anorectal cancer with pagetoid spread

BACKGROUND

Perianal Paget's disease (PPD) is an intraepithelial invasion of the perianal skin and is frequently associated with underlying anorectal carcinoma. The relatively rare nature of this disease has made it difficult to develop treatment recommendations. This study aims to analyze the clinical and pathological features of perianal Paget's disease (PPD) and to explore rational treatment options and follow-up for this disease.

METHODS

The National Cancer Center Hospital database was searched for all cases of perianal Paget's disease diagnosed between 2006 and 2021. In the 14 patients identified, we reviewed the diagnosis, management, and outcomes of adenocarcinoma with pagetoid spread, including suspected or recurrent cases.

RESULTS

All 14 cases met the inclusion criteria. The median follow-up period after diagnosis was 4.5 (range, 0.1-13.0) years. Pagetoid spread before initial treatment was suspected in 12 cases (85.7%). Underlying rectal cancer was identified in 6 cases, and no primary tumor was detected in the other 6 cases. Seven patients had recurrent disease, with the median time to recurrence of 34.6 (range, 19.2-81.7) months. The time to the first relapse was 3 months, and that to the second relapse was 6 months. The overall 5-year survival rate was 90.0%.

CONCLUSIONS

Endoscopic and radiologic evaluation, as well as immunohistologic examination, should be performed. is to differentiate PPD with and without underlying anorectal carcinoma. The time to first recurrence varies widely, and long-term and regular follow-up for more than 5 years is considered necessary for local recurrence and distant metastasis.

Case report and literature review: Robot-assisted laparoscopic left renal mucinous cystadenocarcinoma radical nephrectomy

Background

Mucinous cystadenocarcinoma (MC) of the kidney is a rare renal epithelial tumor originating from the renal pelvic urothelium. There are only a few published reports on MC. Due to its rare and unknown tissue origin, its diagnosis is difficult which almost can be diagnosed through the pathological method.

Case presentation

In this case report, we report a female patient whose chief complaint was low back pain lasting for one month. The three-dimensional computed tomography scan of the urinary system detected approximately 7 cm of a left renal cystic mass. The renal cystic mass was diagnosed as MC after robot-assisted laparoscopic radical nephrectomy. The MC originated from the kidney after completing colorectal adenocarcinoma and ovarian adenocarcinoma.

Conclusions

We reported a case of MC of the kidney which was a rare renal tumor. We not only aimed to present an unusual case of MC and review the previous literature on its pathology and differential diagnosis, but also used new method to treat this type of tumor.

Mucinous Adenocarcinoma of the Colon with Clear Cell Component: A Case Report and Literature Review

Clear cell adenocarcinomas of the colon are defined as a subtype of colorectal adenocarcinoma with clear cell morphology. A 65-year old man was admitted to a Gastroenterology Department for diagnostic evaluation of a tumor in the sigmoid colon found on CT. There, the patient developed complete bowel obstruction and was operated urgently, where intraoperatively, a large tumor in the sigmoid fixated to the lateral abdominal wall was revealed. A subtotal colectomy was performed. Histopathological analysis of the surgical specimen was conducted. The immunohistochemistry staining was positive for CEA, CDX2, and CD20 and negative for CK7, CD10, MUC2, AFP, and PAS staining. Mismatch repair protein testing was negative. The pathological diagnosis was mucinous carcinoma with a clear cell component which bears an extremely low incidence that has been scarcely reported in literature. This stresses the need for more case reports like ours to be published.

Pattern of Expression of CDX2 in Colorectal Cancer and its Role in Prognosis: An Ambispective Observational Study

Introduction Caudal-type homeobox 2 (CDX2), a nuclear protein, is essential for the proliferation and development of intestinal epithelial cells and is frequently downregulated during tumorigenesis. CDX2 inhibits cell growth as well as stimulates differentiation by activating intestinal specific genes, thus lack of CDX2 favors tumor growth and aggressiveness.

Objectives We aimed to evaluate the pattern of CDX2 expression in all stages of colorectal cancer (CRC) and study its association with baseline characteristics and prognosis.

Materials and Methods Study was conducted as an ambispective observational study, enrolling cases of CRC retrospectively from January 2014 to July 2016 (30 months), and prospectively during next 18-month period till January 2018. We performed CDX2 staining by immunohistochemistry on the available biopsy blocks of CRC patients during the study period. Total 286 patients were registered during the study period, of which only 110 biopsy blocks were available for staining. CDX2 scoring was done by a semiquantitative method on whole tissue section for the intensity and percentage of the cells showing positivity. Correlation of CDX2 expression was done with baseline clinical and histopathologic characteristics, and survival.

Results Of 110 patients, 77 (70%) constituted colon cancer and 33 (30%) were rectal cancer. The median age was 54.2 years, 62 (56.4%) being male and 48 (43.6%) female with male-to-female ratio 1.3:1. In the study cohort, 33 (30%) patients had stage II disease, 30 (27.3%) stage III, and 47 (42.7%) were stage IV. Seventy-three (66.4%) were positive for CDX2 and 37 (33.4%) were negative. Loss of CDX2 expression was significantly associated with advanced stage, rectal site, poor grade of differentiation, and presence of lymphovascular invasion (LVSI). With median follow-up of 16 months, progression-free survival (PFS) at 2 years was 30% for CDX2 negative patients compared with 67% for CDX2 positive (p = 0.009), while overall survival (OS) at 2 years was 46% for CDX2 negative versus 77% for positive patients (p = 0.01).

Conclusion Loss of CDX2 expression is associated with advanced stage, higher tumor grade, presence of LVSI, and worse PFS and OS and thereby functions as a poor prognostic factor in CRC.

Loss of SATB2 expression correlates with cytokeratin 7 and PD-L1 tumor cell positivity and aggressiveness in colorectal cancer

Colorectal carcinoma (CRC) is a disease that causes significant morbidity and mortality worldwide. To improve treatment, new biomarkers are needed to allow better patient risk stratification in terms of prognosis. This study aimed to clarify the prognostic significance of colonic-specific transcription factor special AT-rich sequence-binding protein 2 (SATB2), cytoskeletal protein cytokeratin 7 (CK7), and immune checkpoint molecule programmed death-ligand 1 (PD-L1). We analyzed a cohort of 285 patients with surgically treated CRC for quantitative associations among the three markers and five traditional prognostic indicators (i.e., tumor stage, histological grade, variant morphology, laterality, and mismatch-repair/MMR status). The results showed that loss of SATB2 expression had significant negative prognostic implications relative to overall survival (OS) and cancer-specific survival (CSS), significantly shortened 5 years OS and CSS and 10 years CSS in patients with CRC expressing CK7, and borderline insignificantly shortened OS in patients with PD-L1 + CRC. PD-L1 showed a significant negative impact in cases with strong expression (membranous staining in 50-100% of tumor cells). Loss of SATB2 was associated with CK7 expression, advanced tumor stage, mucinous or signet ring cell morphology, high grade, right-sided localization but was borderline insignificant relative to PD-L1 expression. CK7 expression was associated with high grade and SATB2 loss. Additionally, a separate analysis of 248 neoadjuvant therapy-naïve cases was performed with mostly similar results. The loss of SATB2 and CK7 expression were significant negative predictors in the multivariate analysis adjusted for associated parameters and patient age. In summary, loss of SATB2 expression and gain of CK7 and strong PD-L1 expression characterize an aggressive phenotype of CRC.

Metachronous isolated penile metastasis from sigmoid colon adenocarcinoma: A case report

BACKGROUND

Sigmoid colon adenocarcinoma has a high incidence among gastrointestinal tumors, and it very rarely metastasizes to the penis. The literature reports that the prognosis after penile metastasis is generally poor, with a median survival of about 9 mo. Metachronous isolated metastasis to the penis originating from sigmoid colon adenocarcinoma has not been reported so far. Here, we report a case of sigmoid colon adenocarcinoma with isolated penile metastasis occurring 2 years after surgery. The mass was pathologically confirmed as metastatic adenocarcinoma, and oral chemotherapy with capecitabine was given after surgery. The tumor did not recur during the 2-year follow-up period.

CASE SUMMARY

A 79-year-old man presented to the urology department with "a mass located at the root of the penis since 1 mo". Enhanced computed tomography (CT) examination suggested a 12 mm × 10 mm × 9 mm nodule at the root of the right penile corpus cavernosum. Cranial, pulmonary, and abdominal CT; and bone scan did not show any tumorigenic lesions. The carcinoembryonic antigen (CEA) level was slightly elevated (6.01 ng/mL, reference value 0-5 ng/mL). The patient had undergone laparoscopic radical sigmoidectomy for sigmoid colon cancer 2 years ago. The postoperative pathology showed moderately differentiated adenocarcinoma of the sigmoid colon, and the stage was PT2N0M0. The penile mass was removed under general anesthesia. The postoperative pathology showed adenocarcinoma, and immunohistochemistry showed CDX2(+), CK20(+), and Villin(+). Based on the medical history, he was diagnosed with penile metastasis from sigmoid colon adenocarcinoma. The CEA level returned to normal (3.34 ng/mL) 4 d after surgery. Oral chemotherapy with capecitabine was given subsequently, and tumor recurrence was not found during the 2-year follow-up period.

CONCLUSION

To our knowledge, this is a rare case of metachronous isolated penile metastasis from sigmoid colon adenocarcinoma. The penis is a potential site of metastasis of colon adenocarcinoma, and the possibility of metastasis should be considered in patients with a history of colon cancer who present with a penile mass. Solitary penile metastasis can be removed surgically, in combination with chemotherapy, and it may have good long-term outcomes.

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.

An Extremely Rare Case of Thyroid Metastasis from Advanced Gastric Cancer

Metastases to the thyroid area are extremely rare in cancer, more specifically, in gastric cancer, where intraperitoneal metastases are absent. Herein, we describe a case of a 41-year-old man who had advanced gastric cancer with metastasis to the right thyroid area, which was found 6 years after curative surgery. The patient presented with multiple enlarged right cervical lymph nodes and a right thyroid mass of 1.2 cm. We assumed that the patient had primary thyroid cancer as he had no signs of other metastases. We performed fine-needle cytology under ultrasonography on the thyroid nodule. However, with a positive carcinoembryonic antigen and a negative thyroid transcription factor 1 immunohistochemical staining results, the patient was diagnosed with metastatic adenocarcinoma that was of gastric origin. Subsequently, the patient was treated with radiotherapy and chemotherapy. This report aimed to raise the concern that gastric cancer may cause metastasis to the peri-thyroid area, involving the thyroid, parathyroid, and regional lymph nodes.

A case of gastric metastasis originating from right-sided colon cancer 4 years after colectomy

The stomach is rarely a metastatic site of other primary cancers. Gastric metastasis from colonic cancer is exceptional. We hereby report a case of a 54-year-old male patient who underwent a right hemicolectomy for right-sided colon cancer. The pathology exam revealed well differentiated adenocarcinoma, it was classified stage IIb. Regular controls performed including colonoscopy were normal. Four years after colectomy, the patient was admitted for hematemesis with epigastric pain with detoriation of general condition . Gastroscopy revealed a large ulceroproliferative mass in the antropyloric region. Histology showed that this tumor was an adenocarcinoma similar to the primary right colon cancer, which led to the diagnosis of metastatic gastric cancer originating from colon cancer.

Diagnostic and prognostic biomarkers in colorectal cancer and the potential role of exosomes in drug delivery

Colorectal cancer (CRC) is third most common cancer with second most common cause of death worldwide. One fourth to one fifth of the CRC cases are detected at advance stage. Early detection of colorectal cancer might help in decreasing mortality and morbidity worldwide. CRC being a heterogeneous disease, new non-invasive approaches are needed to complement and improve the screening and management of CRC. Reliable and early detectable biomarkers would improve diagnosis, prognosis, therapeutic responses, and will enable the prediction of drug response and recurrence risk. Over the past decades molecular research has demonstrated the potentials of CTCs, ctDNAs, circulating mRNA, ncRNAs, and exosomes as tumor biomarkers. Non-invasive screening approaches using fecal samples for identification of altered gut microbes in CRC is also gaining attention. Exosomes can be potential candidates that can be employed in the drug delivery system. Further, the integration of in vitro, in vivo and in silico models that involve CRC biomarkers will help to understand the interactions occurring at the cellular level. This review summarizes recent update on CRC biomarkers and their application along with the nanoparticles followed by the application of organoid culture in CRC.

Engineered colorectal cancer tissue recapitulates key attributes of a patient-derived xenograft tumor line

The development of physiologically relevantin vitrocolorectal cancer (CRC) models is vital for advancing understanding of tumor biology. Although CRC patient-derived xenografts (PDXs) recapitulate key patient tumor characteristics and demonstrate high concordance with clinical outcomes, the use of thisin vivomodel is costly and low-throughput. Here we report the establishment and in-depth characterization of anin vitrotissue-engineered CRC model using PDX cells. To form the 3D engineered CRC-PDX (3D-eCRC-PDX) tissues, CRC PDX tumors were expandedin vivo, dissociated, and the isolated cells encapsulated within PEG-fibrinogen hydrogels. Following PEG-fibrinogen encapsulation, cells remain viable and proliferate within 3D-eCRC-PDX tissues. Tumor cell subpopulations, including human cancer and mouse stromal cells, are maintained in long-term culture (29 days); cellular subpopulations increase ratiometrically over time. The 3D-eCRC-PDX tissues mimic the mechanical stiffness of originating tumors. Extracellular matrix protein production by cells in the 3D-eCRC-PDX tissues resulted in approximately 57% of proteins observed in the CRC-PDX tumors also being present in the 3D-eCRC-PDX tissues on day 22. Furthermore, we show congruence in enriched gene ontology molecular functions and Hallmark gene sets in 3D-eCRC-PDX tissues and CRC-PDX tumors compared to normal colon tissue, while prognostic Kaplan-Meier plots for overall and relapse free survival did not reveal significant differences between CRC-PDX tumors and 3D-eCRC-PDX tissues. Our results demonstrate high batch-to-batch consistency and strong correlation between ourin vitrotissue-engineered PDX-CRC model and the originatingin vivoPDX tumors, providing a foundation for future studies of disease progression and tumorigenic mechanisms.

Combination of CDX2 H-score quantitative analysis with CD3 AI-guided analysis identifies patients with a good prognosis only in stage III colon cancer

AIM

Stratification of colon cancer (CC) of patients with stage II and III for risk of relapse is still needed especially to drive adjuvant therapy administration. Our study evaluates the prognostic performance of two known biomarkers, CDX2 and CD3, standalone or their combined information in stage II and III CC.

PATIENTS AND METHODS

CDX2 and CD3 expression was evaluated in Prodige-13 study gathering 443 stage II and 398 stage III primary CC on whole slide colectomy. We developed for this study an H-score to quantify CDX2 expression and used our artificial intelligence (AI)-guided tissue analysis ColoClass to detect CD3 in tumour core and invasive margin. Association between biomarkers and relapse-free survival was investigated.

RESULTS

Univariate analysis showed that the combined variable CD3-TC and CD3-IM was associated with prognosis in both stage II and stage III. CDX2, on the contrary, was associated with prognosis only in stage III. We subsequently associated CDX2 and combined immune parameters only in stage III. This multivariate analysis allowed us to distinguish a proportion of stage III CC harbouring a high CDX2 expression and a high immune infiltration with a particularly good prognosis compared to their counterpart.

CONCLUSION

This study validated the prognostic role of CDX2 and CD3 evaluated with immunohistochemistry procedures in stage III but not in stage II. This association would be conceivable in a routine pathology laboratory and could help oncologist to consider chemotherapy de-escalation for a part of stage III patients.

Modeling colorectal cancer: A bio-resource of 50 patient-derived organoid lines

BACKGROUND AND AIM

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. To improve outcomes for these patients, we need to develop new treatment strategies. Personalized cancer medicine, where patients are treated based on the characteristics of their own tumor, has gained significant interest for its promise to improve outcomes and reduce unnecessary side effects. The purpose of this study was to examine the potential utility of patient-derived colorectal cancer organoids (PDCOs) in a personalized cancer medicine setting.

METHODS

Patient-derived colorectal cancer organoids were derived from tissue obtained from treatment-naïve patients undergoing surgical resection for the treatment of CRC. We examined the recapitulation of key histopathological, molecular, and phenotypic characteristics of the primary tumor.

RESULTS

We created a bio-resource of PDCOs from primary and metastatic CRCs. Key histopathological features were retained in PDCOs when compared with the primary tumor. Additionally, a cohort of 12 PDCOs, and their corresponding primary tumors and normal sample, were characterized through whole exome sequencing and somatic variant calling. These PDCOs exhibited a high level of concordance in key driver mutations when compared with the primary tumor.

CONCLUSIONS

Patient-derived colorectal cancer organoids recapitulate characteristics of the tissue from which they are derived and are a powerful tool for cancer research. Further research will determine their utility for predicting patient outcomes in a personalized cancer medicine setting.

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.

Aim: The aim of this study was to investigate the correlation between the aberrant immunostaining of colorectal carcinoma and different clinicopathological characteristics.

Materials and methods: Immunohistochemical expression of CK20, CK7, and CDX2 was evaluated in 71 cases of colorectal carcinoma. Statistical analysis was performed to identify correlations between the morphological characteristics and the immunoprofile of colorectal carcinoma.

Results: Positive cytoplasmic and/or membranous signal for CK20 was observed in 66.2% of colorectal carcinomas. CK7 positive immunostaining was seen in 7% of the cases. In terms of combined expression of CK20 and CK7, the proportion of immunoprofile CK20+/CK7− was the highest, accounting for 46 out of 71 colorectal carcinomas, followed by CK20−/CK7−, then CK20−/CK7+ and CK20+/CK7+. Concerning CDX2, the majority of colorectal carcinomas (87.3%) showed positive staining. Statistically significant correlation was established between CDX2 expression and histologic grade and depth of tumour invasion. Loss of CK20 positivity was associated with higher histologic grade. No association between CK7 expression and histopathologic features was established.

Conclusions: The results support the heterogeneity of colorectal cancer. Over 35% of the cases in this study showed deviations from the expected immunoprofile. This should be taken into consideration when diagnosing colorectal carcinoma in metastatic regions.

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.

Diagnostic and Prognostic Roles of CDX2 Immunohistochemical Expression in Colorectal Cancers

The study is aimed to evaluate the diagnostic and prognostic role of the immunohistochemical expression of the Caudal-type homeobox transcription factor 2 (CDX2) in colorectal cancers (CRCs) through a meta-analysis. By searching relevant databases, 38 articles were eligible to be included in this study. We extracted the information for CDX2 expression rates and the correlation between CDX2 expression and clinicopathological characteristics. The estimated rates of CDX2 expression were 0.882 [95% confidence interval (CI) 0.774−0.861] and 0.893 (95% CI 0.820−0.938) in primary and metastatic CRCs, respectively. Furthermore, based on their histologic subtype, CDX2 expression rates of adenocarcinoma and medullary carcinoma were 0.886 (95% CI 0.837−0.923) and 0.436 (95% CI 0.269−0.618), respectively. There was a significant difference in CDX2 expression rates between adenocarcinoma and medullary carcinoma in the meta-regression test (p < 0.001). In addition, CDX2 expression was significantly lower in CRCs with the BRAFV600E mutation than in CRCs without mutation. Patients with CDX2 expression had better overall and cancer-specific survival rates than those without CDX2 expression. Thus, CDX2 is a useful diagnostic and prognostic marker CRCs.

Four-Year Disease-Free Remission in a Patient With POLE Mutation-Associated Colorectal Cancer Treated Using Anti-PD-1 Therapy

The stability of the human genome depends upon a delicate balance between replication by high- and low-fidelity DNA polymerases. Aberrant replication by error-prone polymerases or loss of function of high-fidelity polymerases predisposes to genetic instability and, in turn, cancer. DNA polymerase epsilon (Pol ε) is a high-fidelity, processive polymerase that is responsible for the majority of leading strand synthesis, and mutations in Pol ε have been increasingly associated with various human malignancies. The clinical significance of Pol ε mutations, including how and whether they should influence management decisions, remains poorly understood. In this report, we describe a 24-year-old man with an aggressive stage IV high-grade, poorly differentiated colon carcinoma who experienced a dramatic response to single-agent checkpoint inhibitor immunotherapy after rapidly progressing on standard chemotherapy. His response was complete and durable and has been maintained for more than 48 months. Genetic testing revealed a P286R mutation in the endonuclease domain of POLE and an elevated tumor mutational burden of 126 mutations per megabase, both of which have been previously associated with response to immunotherapy. Interestingly, tumor staining for PD-L1 was negative. This case study highlights the importance of genetic profiling of both early and late-stage cancers, the clinical significance of POLE mutations, and how the interplay between genetic instability and immune-checkpoint blockade can impact clinical decision-making.

An immunohistochemical expression of CK5/6, CK7, and CK20 on cell blocks in metastatic cervical lymphadenopathy

Background

The neck is a common site of both primary and secondary malignancies. Many tumors from the head and neck (oral cavity, larynx, and pharynx), lung, and gastrointestinal tract metastasize to cervical lymph nodes. At most times, tumors are diagnosed by morphology, sometimes it is difficult to diagnose an unknown primary presenting as metastatic lymphadenopathy solely on the basis of morphology. Specific histological cell types can be confirmed by the use of immunohistochemistry.

Aim

The present study evaluated the utility of cell block over fine-needle aspiration cytology (FNAC) and immunohistochemical expression of CK5/6, CK7, and CK20 in metastatic cervical lymphadenopathy.

Methods:

This prospective study design was used on a total of 50 cases. FNAC smears and cell blocks were made in all the cases. All the cell blocks were compared with FNAC findings and further subjected to immunohistochemical (IHC) analysis. The necessary statistical analysis was done.

Results and Conclusion

Our study showed that the combined use of the cell block technique and FNAC was more useful and sensitive in diagnosing the metastatic cervical lymph nodes and the accuracy can be further improved by the use of IHC on the cell blocks. The combined use of CK5/6, CK7, and CK20 in metastatic cervical lymphadenopathy is helpful in diagnosing squamous cell carcinoma and adenocarcinoma with known/unknown primary sites.

Ductal breast carcinoma metastasized to the rectum: A case report and review of the literature

BACKGROUND

Gastrointestinal (GI) metastasis from breast cancer (BC) is rarely encountered in clinical practice. Nonspecific symptoms and long intervals make early diagnosis difficult. Therefore, increased awareness of GI metastasis secondary to BC and a deep understanding of the clinical and pathological features, and intervention for GI metastasis are fundamental to avoid delay in correct diagnosis and management.

CASE SUMMARY

The present report discusses the case of a Chinese female patient aged 36 years. The patient presented with difficult defecation along with bloody stools and hypogastralgia. In 2015, she had undergone right modified radical mastectomy and axillary lymph node dissection in another hospital to treat the infiltrating ductal breast carcinoma pT1N1M0. The presenting symptoms were investigated by colonoscopy, which indicated a circumferential stricture in the lower rectum at 3 cm from the anal edge. Further investigation with positron emission tomography-computed tomography revealed an uptake of fluorodeoxyglucose within the distal rectum as well as in the left acetabulum. The samples from laparoscopic exploration were biopsied, which revealed metastases of BC. Immunohistochemical analysis of the tumor confirmed that the patient had rectal metastasis of infiltrating ductal BC.

CONCLUSION

Rectal metastasis should be considered when patients with a history of BC present with changed bowel habits.

[A Case of Ascending Colon Cancer with Skull Metastasis]

A 55-year-old woman became aware of a tumor on the left side of the head in July, 2020 and was referred to our hospital in September because of its rapid growth. A head CT showed a neoplastic lesion of the skull. A CT from the neck to the pelvis revealed an ascending colon tumor and multiple lesions in the liver, which was suspected as metastasis. A colonoscopy also showed a type 2 like lesion in the ascending colon, and a biopsy showed adenocarcinoma. A pedunculated polyp had been pointed out in the ascending colon at another hospital four years previously, and the pathological result was an adenoma, but endoscopic mucosal resection was not performed. It is considered that the adenoma became advanced colon cancer with metastasis through the mechanism of multistage carcinogenesis. Metastatic lesions of the ascending colon cancer was suspected with regard to the skull lesion. In addition to the rapid growth, surgical removal was desirable from the viewpoint of cosmetology, and surgery was performed in November. The postoperative pathological diagnosis was a metastatic skull tumor derived from ascending colon cancer. The diagnosis was Stage IVb according to the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma (9^th Edition). Although chemotherapy was started after surgery, the metastatic liver cancer increased rapidly and the patient passed away in April, 2021.

Rare Metastasis of Gastric Cancer to the Thyroid Gland: A Case Report and Review of Literature

Background: It is common for patients with gastric cancer to develop distant metastases in the liver, lung, bone, and brain. Although the thyroid also has an abundant blood supply, gastric cancer metastasis to the thyroid is uncommon. Due to the rarity of such metastasis, its clinical features are not well understood. Here, we present the case of a patient with gastric cancer metastasis to the thyroid treated at our hospital.

Case Summary: We report the case of a 63-year-old female with a mass in the anterior neck and mild hoarseness for 6 months. The patient underwent proximal subtotal gastrectomy for Siewert III oesophagogastric junction cancer 6 years ago. Subsequently, she received 8 cycles of adjuvant chemotherapy. Her condition was stable until mild hoarseness developed for no apparent reason 6 months prior to presenting at our clinic. Both ultrasonography and computed tomography confirmed a heterogeneous mass in the right lobe of the thyroid gland. Blood thyroid function tests and tumor marker expression levels were normal. Thyroid malignancy was suspected, and the patient underwent a right thyroidectomy. During the surgery, a tumor was found that had invaded the right recurrent laryngeal nerve and trachea. H&E staining and immunohistochemistry results suggested that the cancer cells originated from gastric cancer. The patient was diagnosed with thyroid metastasis of gastric cancer. She refused further treatment and died within 6 months.

Conclusion: Metastasis of gastric cancer to the thyroid is rare and is associated with a poor prognosis. Immunohistochemical diagnosis is essential for a conclusive diagnosis. For patients with a history of malignant tumors, the possibility of metastatic thyroid nodules should be ruled out when diagnosing thyroid nodules.

Histopathological and Immunohistochemical Evaluation of CDX2 and Ki67 in Colorectal Lesions with their Expression Pattern in Different Histologic Variants, Grade, and Stage of Colorectal Carcinomas

Background:

A variety of colorectal lesions are surgically treated encompassing both benign and malignant polyps and colorectal cancer (CRC). CRC is the third most common cause of death in developed countries. Over the last decade, CDX2 has been linked to CRC progression, with reduced expression of the protein associated with more advanced tumor stage, vessel invasion, and metastasis.

Aims and Objectives:

To analyze the histopathology and immunohistochemistry (IHC) of CDX2 and Ki67 with their expression pattern; in different lesions of colon and rectum with special reference to various grade/stage/histological variants of CRC and to find out whether they can be used as possible predictive marker.

Materials and Methods:

The study conducted was hospital based, both retrospective and perspective type comprising colorectal samples of total 367 cases (N) within a period of 2½ years. Surgical samples were collected, then grossed, processed, stained with routine hematoxylin and eosin stain in our department followed by IHC of CDX2 and Ki67 in only 60 randomly selected cases (n = 60).

Results:

Out of total 367 cases, 265 cases were prospective study and 102 cases were retrospective study (240 cases were colonic lesions, and 127 are rectal lesions). The samples included were both from colonoscopy biopsy (small) 319 cases and 48 colectomy specimen (large). Mean age of the study participants was 49.62 years with a standard deviation of 17.34 years and predominantly male, but the difference was not statistically significant (P > 0.05). Colon (238 cases, 64.9%) as a whole affected more than rectum and left sided tumors more than the right side. All 60 cases were found to be positive for CDX2 expression (i.e., 100%); majority (n = 38) being carcinoma cases possessing high score and was statistically significant (P = 0.008, using Chi-square test) indicating strong association, whereas Ki-67 showed an increased index from noneoplastic to neoplastic cases.

Conclusion:

These markers can be used as future predictive biomarkers which will precisely evaluate risk group, prognosis, and response to therapy hence can be used as target therapy reducing irrational treatment.

Vaginal oligometastatic disease of colorectal primary: Report of a novel therapeutic approach

Vaginal oligometastatic disease of colorectal primary is a rare malignancy with few reported cases in the literature and no standardized treatment paradigm. We report on the definitive management of an unusual case of an elderly woman with the aforementioned disease. A 78-year-old African-American woman presented with vaginal spotting and was found to have a vaginal lesion. Final pathology was consistent with moderately differentiated adenocarcinoma of colorectal primary. Extensive work up, which included endoscopies, pathologic analyzes, and imaging workup, did not reveal a primary gastrointestinal malignancy. The patient underwent partial vaginectomy and final pathology once again confirmed moderately differentiated adenocarcinoma of colorectal primary (CDX 2 and CEA positive, ER/PR, and CK 7 negative) with negative margins. She went on to receive adjuvant concurrent chemoradiation with 5-FU based chemotherapy. She received 45 Gy in 25 fractions to the whole pelvis followed by an HDR brachytherapy boost to 12 Gy in two fractions. Unfortunately, 10 months after completing radiation, she was found to have adenocarcinoma arising from a hepatic flexure colon polyp on colonoscopy. She required definitive surgical resection and was staged as mpT3N0M1. She received 12 cycles of 5-FU and at 2-year follow-up was found to be disease free with no evidence of locoregional recurrence or distant metastatic disease. Continued long-term follow up is warranted.

Cytokeratin 7 expression as a predictor of an unfavorable prognosis in colorectal carcinoma

Colorectal carcinoma (CRC) is associated with significant morbidity and mortality worldwide. Cytokeratins (CKs) are widely expressed in various types of carcinomas, whereas in CRC it is usually CK7 − and CK20 + . A subset of CRCs is CK7 + . This study aims to determine the prevalence of CK7 expression in CRC and its impact on overall survival. We analyzed 300 randomly selected surgically treated CRC cases using paraffin embedded tumor tissue samples and evaluated CK7 and CK20 expression using the tissue microarray method. Tumors with positivity > 10% and > 25% of tumor cells were considered CK7 and CK20 positive, respectively. Expression of both CKs and several clinical-pathological variables (stage, grade, laterality, mismatch-repair/MMR status) were evaluated using patient follow up data (Kaplan–Meier analysis of cancer-specific survival (CSS)). Significant results include shorter CSS (restricted mean 4.98 vs. 7.74 years, P = 0.007) and 5-year survival (29.4% vs. 64.6%, P = 0.0221) in CK7 + tumors compared to CK7 − tumors, respectively; without significant association with grade, stage or right-sided location. These results were significant in a multivariate analysis. CK20 + tumors are more frequently MMR-proficient and left-sided. MMR-deficient tumors are more frequently right-sided and had longer survival. CK7 expression, right-sided location (rmean CSS 6.83 vs. 8.0 years, P = 0.043), MMR-proficiency (rmean CSS 7.41 vs. 9.32 years, P = 0.012), and UICC stages III + IV (rmean CSS 6.03 vs. 8.92 years, P < 0.001) of the tumor correlated with negative prognostic outcomes, whereas the most significant results concern stage and CK7 positivity. The result concerning negative prognostic role of CK7 differs from those obtained by several previous studies focused on this topic.

MiR-30a and miR-200c differentiate cholangiocarcinomas from gastrointestinal cancer liver metastases

Prior studies have demonstrated the utility of microRNA assays for predicting some cancer tissue origins, but these assays need to be further optimized for predicting the tissue origins of adenocarcinomas of the liver. We performed microRNA profiling on 195 frozen primary tumor samples using 14 types of tumors that were either adenocarcinomas or differentiated from adenocarcinomas. The 1-nearest neighbor method predicted tissue-of-origin in 33 samples of a test set, with an accuracy of 93.9% at feature selection p values ranging from 10-4 to 10-10. According to binary decision tree analyses, the overexpression of miR-30a and the underexpression of miR-200 family members (miR-200c and miR-141) differentiated intrahepatic cholangiocarcinomas from extrahepatic adenocarcinomas. When binary decision tree analyses were performed using the test set, the prediction accuracy was 84.8%. The overexpression of miR-30a and the reduced expressions of miR-200c, miR-141, and miR-425 could distinguish intrahepatic cholangiocarcinomas from liver metastases from the gastrointestinal tract.