Lymphoepithelioma-like carcinoma of the duodenum: a very infrequent tumor

Pathological diagnosis and clinical feature analysis of descending duodenal mucosal adenocarcinoma: A case report

BACKGROUND

Mucosal adenocarcinoma of the descending duodenum is a very rare gastrointestinal tumor. Due to its low incidence, it has rarely been the focus of clinical and pathological studies. The clinical manifestations of these tumors are usually nonspecific, and they are easily misdiagnosed or missed. Pathological diagnosis is the gold standard for diagnosis, but due to the small number of cases, the relevant pathological characteristics and diagnostic criteria are not completely clear. The purpose of this study was to deepen the understanding of the diagnosis and treatment of this disease and to provide a clinical guidance.

CASE SUMMARY

A 61-year-old woman who was hospitalized with recurrent abdominal pain for more than 20 days. The patient developed epigastric pain with no obvious cause more than 20 days prior, mainly left epigastric pain and middle epigastric pain, and presented persistent dull pain without nausea or vomiting, fever or chills. The patient was treated at a local hospital, gastroscopy revealed a new lesion in the circum-intestinal cavity in the descending part of the duodenum, and pathological biopsy revealed mucous adenocarcinoma in the descending part of the duodenum. Currently, for further diagnosis and treatment, the patient is admitted to our hospital for surgical treatment for "malignant tumor of the duodenum" in the outpatient department.

CONCLUSION

Mucosal adenocarcinoma of the descending duodenum has a high misdiagnosis rate and missed diagnosis rate, clinical manifestations lack specificity, and pathological diagnosis is the main basis for diagnosis.

Lymphoepithelial Carcinoma of the Lung: A Case Report and Review of the Literature

Lymphoepithelial or lymphoepithelioma-like carcinoma is a poorly differentiated carcinoma located outside the nasopharynx with similar morphologic characteristics to its nasopharyngeal counterpart. Lymphoepithelial carcinoma of the lung is a rare subtype of squamous cell lung carcinoma frequently associated with Epstein-Barr virus (EBV) infection, accounting for approximately 1% of non-small cell lung carcinomas (NSCLC). We herewith present a case of a 78-year-old female patient who was diagnosed with lymphoepithelial carcinoma of the lung, emphasizing its distinct epidemiological features, clinical workup, and histopathological characteristics. Furthermore, we discuss its histologic differential diagnosis. Finally, we refer to this tumor's unique molecular and immunological profile and its treatment modalities, and we review the literature.

Lymphoepithelioma-like gastric adenocarcinoma. Descriptive case series

Lymphoepithelioma-like gastric adenocarcinoma is characterised by a large reactive lymphoplasmacytic infiltrate in the stroma and islets of undifferentiated cells, which express intense and widespread Epstein-Barr virus (EBV). This tumour type has higher survival rates than other gastric cancers, a more proximal location and less lymphatic spread. Our aim is to describe the clinical and pathological characteristics of our series of lymphoepithelioma-like gastric adenocarcinoma. We selected patients who underwent surgery for gastric adenocarcinoma lymphoepithelioma-like variant from 2014 onwards. The results of the following variables were collected: age (years), sex, pre-diagnostic clinical time (months), gastric tumour location, endoscopic biopsy histology, surgical technique, in situ hybridisation for EBER region (Epstein-Barr virus-associated non-coding RNA), microsatellite instability, degree of differentiation, level of resection, tumour size (cm), TNM T value, lymphadenopathy/resected node ratio, overall survival (months) and vital status. Our experience in the lymphoepithelioma-like variant presents as an advanced gastric cancer, possibly related to long-standing prediagnostic symptoms. It behaves as a tumour with expansive local growth with little capacity for lymphatic or metastatic involvement, which could be explained by the prominent intratumoral lymphoid stroma that acts as an antimetastatic barrier.

Molecular characteristics of primary pulmonary lymphoepithelioma-like carcinoma based on integrated genomic analyses

Primary pulmonary lymphoepithelioma-like carcinoma (pLELC) is a rare non-small cell lung cancer (NSCLC) subtype. Clinical features have been described in our previous report, but molecular characteristics remain unclear. Herein, pLELC genomic features were explored. Among 41,574 lung cancers, 128 pLELCs and 162 non-pLELC NSCLCs were enrolled. Programmed cell death ligand 1 (PD-L1) and protein 53 (p53) expression was detected in 47 surgically resected pLELC samples by immunohistochemical assays. Multiomics genomic analyses, including whole-genome sequencing (WGS), RNA whole-transcriptome sequencing (RNA-seq), and Epstein-Barr virus (EBV) integration analyses, were performed on eight frozen pLELC tissues and compared with 50 lung adenocarcinomas (LUADs) and 50 lung squamous cell carcinomas (LUSCs) from The Cancer Genome Atlas (TCGA) and another 26 EBV-positive nasopharynx cancers (EBV⁺-NPCs). Progression-free survival (PFS) and overall survival (OS) of pLELC patients were better than those of non-pLELC patients. High PD-L1 or p53 expression was associated with extended disease-free survival (DFS). pLELC had 14 frequently mutated genes (FMGs). Somatically mutated genes and enrichment of genetic lesions were found, which differed from observations in LUAD, LUSC, and EBV⁺-nasopharyngeal carcinoma (NPC). Three tumor-associated genes, zinc finger and BTB domain-containing 16 (ZBTB16), peroxisome proliferator activated receptor gamma (PPARG), and transforming growth factor beta receptor 2 (TGFBR2), were downregulated with copy number variation (CNV) loss. EBV was prone to integrating into intergenic and intronic regions with two upregulated miR-BamH1-A rightward transcripts (BARTs), BART5-3P and BART20-3P. Our findings reveal that pLELC has a distinct genomic signature. Three tumor-associated genes with CNV loss and two miR-BARTs might be involved in pLELC tumorigenesis.