Lymphoid Stroma Research Articles

Clinicopathologic and molecular characterization of stages II-IV gastric cancer with Claudin 18.2 expression

Abstract Background Claudin 18.2 (CLDN18.2) is a promising target for targeted therapies in gastric cancer (GC). This study investigated the prevalence of CLDN18.2 expression in patients with stages II-IV GC or gastroesophageal junction (GEJ) adenocarcinoma and its correlation with clinicopathologic features and other crucial GC biomarkers. Methods We enrolled 1000 patients diagnosed with stages II-IV GC after surgical treatment. Immunohistochemistry for CLDN18 (43-14A clone), PD-L1 (22C3 pharmDx), HER2, and FGFR2 was performed. CLDN18.2 positivity was defined as moderate-to-strong (2+/3+) membranous staining in ≥75% of tumor cells. CLDN18.2 expression was compared with biomarker expression, Epstein-Barr virus (EBV) association and microsatellite instability status, and clinicopathologic features. Result CLDN18.2 was positive in 34.4% of the patients. CLDN18.2 positivity was significantly higher in the middle and upper thirds than in the lower third gastric location (P < .001), but there was no correlation with age, sex, or stage (P > .05). CLDN18.2 positivity was rare (2.8%) in mucinous adenocarcinoma but frequent (90.9%) in a majority of gastric carcinomas with lymphoid stroma. CLDN18.2 positivity was higher in EBV-associated (P < .001) and PD-L1-positive (PD-L1 CPS ≥ 5) GC (P = .014) but lower in HER2 positive GC (P = .005). CLDN18.2 positivity was not significantly associated with overall survival and disease-free survival. Conclusion This study provides a comprehensive evaluation of CLDN18.2 status and its correlation with the clinicopathologic characteristics of patients with stages II-IV GC in Korea and with crucial biomarkers. It may be valuable for guiding future drug development, expanding treatment options, and ultimately improving patient outcomes in GC.

Warthin tumor concomitant with mantle cell lymphoma: a case report and review of literature

RationaleWarthin tumor (WT) is the second most common benign tumor in salivary gland. It has a slow growth rate and most frequently occurs in the parotid gland. Most patients present with an incidental finding of a painless mass inferior/anterior to the ear. Besides the epithelial component of the tumor, WT is characteristically associated with lymphoid stroma that is considered benign. While there have been a few reports of malignant transformation of the lymphoid components in WT, cases of WT concomitant with mantle cell lymphoma (MCL) are extremely rare. To the best of our knowledge, two cases have been described in the English literature. Herein, we report a case of WT concomitant with MCL in a 70-year-old female patient, and emphasize the importance of careful examination of lymphoid stroma in WT so that concurrent lymphoma is not missed.Patient concernsA 70-year-old Chinese woman with a 40-year history of cigarette smoking presented with a one year history of a right submaxillary mass with recent enlargement.DiagnosisCervical ultrasound (US) and computed tomography (CT) scans of the neck revealed a well-circumscribed mass in the right parotid with a maximum diameter of 3.1 cm. Surgical resection of the mass was performed. Histopathological examination revealed a characteristic double-layer of neoplastic epithelium with prominent lymphoid stroma, suggesting WT. In addition, morphology and immunohistochemistry studies confirmed the coexistence of MCL. Thereafter, the final diagnosis of this case was WT concomitant with MCL.InterventionsThe patient was staged as stage I after clinical assessment. Due to the slow growth of parotid lesions, close observation was decided with periodic clinical and radiological monitoring.OutcomesCurrently, the patient demonstrates a stable disease by clinical evaluation.LessonsTo the best of our knowledge, reported cases of WT concomitant with MCL are very rare. This case highlights the importance of a comprehensive assessment of the lymphoid stroma of WT to avoid missed diagnosis of a lymphoma component in a collision tumor.

Assessing Morphological Diversity of Acinic Cell Carcinoma of Salivary Glands at a Tertiary Care Hospital in Pakistan.

Acinic cell carcinoma (AciCC) is a rare clinical entity and a salivary gland malignancy. It is associated with wide histological variations in the cytomorphological patterns. Sixty cases diagnosed as AciCC from 2002 to 2023 were assessed for diverse cytomorphological patterns. The mean age of patients at the time of diagnosis was 44.35±16.8 years ranging from 15 to 81 years. Females comprised 58.3% for a F: M ratio of 1.4:1. Fifty three cases (88.3%) occurred in the parotid gland, two cases in the nasal region (3.3%), and one case each in the soft plate and upper lip (1.7%). The location of the remaining three cases was not specified. The most common presenting complaint was a well-defined facial swelling associated with pain. The average tumor size was 3.8±1.9 cm. The most predominant architectural pattern was solid (83.3%) followed by microcystic (60%), then follicular (41.7%), papillary cystic (14.3%), and tubulocystic (28.6%), and AciCC with de-differentiation/high-grade transformation was reported in three cases (5%). In 83.3% of the cases (50 out of 60), we noticed a mixture of two or more growth patterns.Other degenerative changes included prominent lymphoid stroma, hemorrhage, and cystic change. Awareness and recognition of diverse cytomorphological patterns of AciCC, especially in institutions of a developing country where there is limited availability of highly specific and sensitive immunohistochemical stains or molecular diagnostics, are crucial and essential.

Micronodular thymic epithelial tumors with lymphoid hyperplasia and mimicking lesions.

Micronodular arrangement of epithelial cells and lymphoid B-cell hyperplasia with follicles are both peculiar histological features in thymic tissue. Such features may especially occur in thymic epithelial tumors. The most common form is called micronodular thymoma with lymphoid stroma. We have recently described some characteristics of thymic micronodular carcinoma with lymphoid hyperplasia, highlighting how this carcinomatous counterpart should not be misdiagnosed as a thymoma. In this review, we discuss these two entities but also other mimics, which may occur in the anterior mediastinum. These mimics include various types of cellular micronodules and lymphoid backgrounds encompassing a wide range of mediastinal lesions. Non-neoplastic lesions, such as thymic nodular epithelial hyperplasia, thymic lymphoid hyperplasia, or sarcoidosis, as well as tumors of very varying aggressiveness, such as micronodular thymic epithelial tumors, low-grade lymphoma, seminoma, or lymphoepithelial carcinoma, are discussed. We show how these lesions may be misleading and we describe how a correct diagnostic may be obtained in current practice.

C-C Chemokine 21-Expressing T-cell Zone Fibroblastic Reticular Cells, Abundant in Lymph Nodes, Are Absent in Cancer Lymphoid Stroma.

Cancer tissue generally possesses an immunosuppressive microenvironment. However, some cancers are associated with lymphoid stroma (i.e., a widely developed tertiary lymphoid structure). The T-cell zone (paracortex) of secondary lymphoid organs, particularly lymph nodes, is characterized by an abundance of T-cell zone fibroblastic reticular cells (TCZ-FRCs) that express C-C motif chemokine ligand 21 (CCL21) and smooth muscle actin (SMA). We analyzed the presence of TCZ-FRCs in 30 cases of carcinomas with lymphoid stroma of the breast, stomach, colon, tongue, and skin. Immunohistochemistry corroborated the abundance of CCL21+ SMA+ TCZ-FRCs in the normal lymph nodes. In sharp contrast, all 30 carcinomas with lymphoid stroma displayed no CCL21+ SMA+ TCZ-FRCs despite the affluence of T cells. Real-time reverse transcription polymerase chain reaction confirmed a marked decrease in the messenger ribonucleic acid expression of CCL21 and its receptor C-C motif chemokine receptor 7 in cancer lymphoid stroma compared to that in lymph nodes. Next, we analyzed the T cell phenotypes. The cancer lymphoid stroma demonstrated an abundance of CD3+ CD62L- memory-type T cells, in contrast to the presence of CD3+ CD62L+ naïve- and central memory T cells in the T cell zone of lymphoid tissues. Our data demonstrated the following: 1) Cancer lymphoid stroma lacked TCZ-FRCs with abundance of more activated T cells than in lymph nodes and 2) these were common phenomena in cancer lymphoid stroma irrespective of the histological types and organs involved.

The role of fibrinogen-like protein 1 in immune escape and tumor growth mechanism of Warthin’s tumor

Background: One of the benign tumors of the salivary glands is Warthin’s Tumor (WT), which consists of cystic bilayer papillary epithelial cells accompanied by the presence of a lymphoid stroma. Several cases have been reported to turn malignant. One of the markers developed to identify tumor proteins is fibrinogen-like protein 1 (FGL1). Along with lymphocyte-activation gene 3 (LAG-3), FGL1 establishes an immune checkpoint pathway that plays a role in the mechanism of tumor immune escape. Not much has been reported regarding FGL1 expression in WT, but some studies have reported that its expression is associated with tumor growth. Purpose: This study aims to analyze the location of FGL1 expression in WT and its relation to the mechanism of tumor immune release through the interaction between FGL1 and LAG-3. Methods: Cases of WT (n = 11) and breast cancer (n = 1) were used as positive controls. All cases were stained with hematoxylin-eosin and Recombinant Anti-FGL1 antibody. The FGL1 expression was observed in the cell membrane, cytoplasm, and lymphoid stroma. The results are presented in the form of figures. Results: All cases of WT expressed FGL1 in the cell membrane, cytoplasm, and lymphoid stroma. Its expression in the cell membrane and cytoplasm is possibly related to the process of tumorigenesis and the increasing size of the lesion. Additionally, its expression is seen in the lymphoid stroma, which is closely related to immune escape by inhibiting lymphocytes against tumor cells. Conclusion: Warthin’s tumor cells express FGL1, and this expression plays a role in tumor immune escape mechanisms and tumor growth.

Warthin’s Tumor in Submandibular Salivary Gland: An Uncommon Extra Parotid Location

Introduction: Salivary gland tumors are complex to diagnose both on histopathology and cytology. Majority of these tumours arise in the parotid glands, followed by submandibular glands, and rarely in minor salivary glands. Warthin’s tumor (WT), also known as papillary cystadenoma lymphomatosum, is characterized by a dense lymphoid stroma and a double layer of oncocytic epithelium with papillary and cystic architecture. Only 6-10% cases have been reported in the extra-parotid locations i.e. cervical lymph nodes, submandibular gland and larynx. Case Report: Our patient presented with painless bilateral submandibular swellings for 1.5 months with history of chronic smoking of two bundles of biddis per day for 32 years. Conclusion: Hereby, this case was unique in its presentation as it was located in an extra parotid region with bilateral origin, as these locations carry clinical significance in diagnosing and ruling out conditions like lymphoma.

Tumor-driven stromal reprogramming in the pre-metastatic lymph node

Background Metastatic dissemination is critically reliant on the formation of a receptive niche, a process which is thought to rely on signals derived from the primary tumor. Lymph nodes are continuously exposed to such signals through the flow of afferent lymph, allowing the potential reprograming of lymphoid tissue stroma in support of metastases or immunosuppression. The objective of this study was therefore to better characterize tumor-driven transcriptomic changes occurring to specific stromal populations within the tumor-draining lymph node. Methods We utilize single cell RNA sequencing of dissociated LN tissue extracted from tumor-bearing and naïve mice to profile the reprograming of tissue stroma within the pre-metastatic lymph node. Results Resulting data provides transcriptomic evidence of tumor-induced imprinting on marginal reticular cells (MRCs) and floor lymphatic endothelial cells (fLECs) populating the subcapsular sinus. These alterations appear to be unique to the tumor-draining LN and are not observed during inflammatory antigenic challenge. Notably, MRCs exhibit characteristics reminiscent of early desmoplastic CAF differentiation, fLECs engage distinct chemoattractant pathways thought to facilitate recruitment of circulating cancer cells, and both stromal populations exhibit signs of metabolic reprograming and immune-modulating potential. Conclusions Cumulatively, these findings build upon existing literature describing pre-metastatic niche formation and offer several promising avenues for future exploration.

Micronodular thymoma with lymphoid stroma: As benign as it sounds.

Micronodular thymoma (MNT) is a rare subtype of thymoma (reported incidence is approximately 1-5%). We report a case received as a core biopsy from the "right lung mass" of a 31-year-old female. CT scan showed an 8.1 cm large well-defined mass lesion in the right middle lobe, causing indentation and mild compression of the right atrium. Microscopically, the biopsy showed a thymic neoplasm comprised of multiple discrete and coalescing nodules of bland epithelioid tumor cells separated by an epithelial cell-free lymphocyte-rich stroma. On immunohistochemistry, cytokeratin highlighted the thymic epithelial cells. The lymphoid cells showed a naive T-cell phenotype (TdT+ CD 3+). It is worthwhile recognizing this rare variant of thymoma as almost all the patients present with localized low stage disease with rare/no reports of recurrences or distant metastases.

Endoscopic transmural resection as an alternative to colorectal surgery after high-risk (non-curative) endoscopic resection.

Endoscopic full-thickness resection (eFTR) is an emerging technique that enables effective and safe management of complex colorectal lesions. The full-thickness resection device (FTRD®, Ovesco, Germany) has primarily been used for non-exposed transmural resection of challenging subepithelial or epithelial lesions, where conventional methods may be limited. This technique represents an alternative to surgery in selected patients, and its applications are rapidly expanding. In recent years, eFTR has been described as an alternative to surgery for scars aiming to exclude residual tumors after non-curative endoscopic resection. We present a case of a 41-year-old woman with Lynch syndrome (dMLH1) with rectal adenocarcinoma at the age of 20 underwent anterior resection of the rectum and adjuvant chemoradiotherapy. At the age of 39, during endoscopic surveillance, she presented with a suspicious lesion (Paris 0-Is+IIa, NICE2, JNET2B) measuring 16mm in the hepatic angle, and underwent en bloc endoscopic mucosal resection (EMR). Histopathological analysis revealed a low-grade invasive adenocarcinoma with lymphoid stroma with deep invasion of the submucosa and resection margin involvement (vertical R1). After a multidisciplinary team discussion, complementary surgery was proposed but the patient refused, opting for close endoscopic and imaging surveillance. Two subsequent colonoscopies plus computed tomography (CT) scans showed no signs of macro or microscopic residual or recurrent tumor, even after extensive biopsies of the colonic scar. However, a CT scan 20months post-resection showed a de novo 2cm thickening of the parietal wall in the hepatic angle, consistent with the location of the previous endoscopic resection. Suspecting deep parietal tumor recurrence without superficial endoscopic findings, a transmural endoscopic resection using FTRD® of the EMR scar was performed, whose histology revealed no transparietal tumor recurrence.

Unusual or Uncommon Histology of Gastric Cancer.

This review comprehensively examines the diverse spectrum of gastric cancers, focusing on unusual or uncommon histology that presents significant diagnostic and therapeutic challenges. While the predominant form, tubular adenocarcinoma, is well-characterized, this review focuses on lesser-known variants, including papillary adenocarcinoma, micropapillary carcinoma, adenosquamous carcinoma, squamous cell carcinoma (SCC), hepatoid adenocarcinoma, gastric choriocarcinoma, gastric carcinoma with lymphoid stroma, carcinosarcoma, gastroblastoma, parietal cell carcinoma, oncocytic adenocarcinoma, Paneth cell carcinoma, gastric adenocarcinoma of the fundic gland type, undifferentiated carcinoma, and extremely well-differentiated adenocarcinoma. Although these diseases have different nomenclatures characterized by distinct histopathological features, these phenotypes often overlap, making it difficult to draw clear boundaries. Furthermore, the number of cases was limited, and the unique histopathological nature and potential pathogenic mechanisms were not well defined. This review highlights the importance of understanding these rare variants for accurate diagnosis, effective treatment planning, and improving patient outcomes. This review emphasizes the need for ongoing research and case studies to enhance our knowledge of these uncommon forms of gastric cancer, which will ultimately contribute to more effective treatments and better prognostic assessments. This review aimed to broaden the pathological narrative by acknowledging and addressing the intricacies of all cancer types, regardless of their rarity, to advance patient care and improve prognosis.

Mucoepidermoid carcinoma with Warthin like features- rare case report

Mucoepidermoid carcinoma with Warthin like features is a deceptive tumour and can be potentially misdiagnosed as a Warthin tumour which is benign, Warthin tumour with mucinous and squamous metaplasia or MEC transformed from Warthin tumour. We are presenting a case of a 25-year-old woman with recurrent solitary mass in the left parotid gland. Microscopically it consists of predominantly cystic areas and focal solid infiltrative tumour with mucinous, intermediate and epidermoid cells having complex architecture in a fibrotic stroma. Extracellular mucin pools seen. Cystic areas are lined by monolayered as well as bilayer epithelium with lymphoid stroma (Warthin like morphology). Occasional mitosis noted. No necrosis and perineural invasion seen. Immunohistochemically, the tumour is positive for P63, P40, CK5/6, EMA, Mucicarmine stain, diffusely positive for CK7. We reached at the final conclusion of low grade MEC, Warthin like features. Even though the cytogenetic studies are confirmatory, we emphasize the role of histomorphology study with IHC and clinical history in identifying this rare variant of MEC with Warthin like features.

Genetic landscape and PD-L1 expression in Epstein–Barr virus-associated gastric cancer according to the histological pattern

Epstein–Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct molecular subtype of gastric cancer. This study aims to investigate genomic and clinicopathological characteristics of EBVaGC according to the histological pattern. We retrospectively collected 18 specimens of surgically resected EBVaGCs. Whole-exome sequencing was performed for all cases. Moreover, PD-L1 expression and tumor-infiltrating lymphocyte (TIL) percentage were investigated. Among 18 EBVaGCs, 10 cases were of intestinal histology, 3 were of poorly cohesive histology, and the remaining 5 were of gastric carcinoma with lymphoid stroma histology. Whole-exome sequencing revealed that EBVaGCs with intestinal histology harbored pathogenic mutations known to frequently occur in tubular or papillary adenocarcinoma, including TP53, KRAS, FBXW7, MUC6, ERBB2, CTNNB1, and ERBB2 amplifications. One patient with poorly cohesive carcinoma histology harbored a CDH1 mutation. Patients with EBVaGCs with intestinal or poorly cohesive carcinoma histology frequently harbored driver mutations other than PIK3CA, whereas those with EBVaGCs with gastric carcinoma with lymphoid stroma histology lacked other driver mutations. Moreover, the histological pattern of EBVaGCs was significantly associated with the levels of TILs (P = 0.005) and combined positive score (P = 0.027). In conclusion, patients with EBVaGCs with different histological patterns exhibited distinct genetic alteration, PD-L1 expression, and degree of TILs.

P16 expression and presence of lymphoid stroma are correlated with good prognosis in mucoepidermoid carcinoma of the head and neck

BackgroundMucoepidermoid carcinoma (MEC) is the most common salivary gland malignancy. This study was designed to identify valuable prognosticator in MEC. MethodsHistopathologic analysis, immunohistochemistry, and in situ hybridization were performed on 128 carcinomas diagnosed as MEC of the head and neck. ResultsExpression of p16 was found in 96 cases (76%) of MEC. Lymphoid stroma was identified in 63 cases (49%). There was a significant correlation between loss of p16 expression and absence of lymphoid stroma. Expression of p16 was significantly associated with better clinicopathologic features. Lymphoid stroma was significantly associated with lower histologic grade. Overall survival (OS) was significantly longer in cases expressing p16 (P = 0.00096) and lymphoid stroma cases (P = 0.0023). Multivariate analysis revealed loss of p16 expression as negative prognosticators for OS. ConclusionOur data showed p16 expression and the presence of lymphoid stroma were significantly associated with good clinical outcomes. Testing for these factors could lead to better prognostication and treatment of patients with MEC.

A Rare Case of Primary Adenocarcinoma of the Gallbladder With Lymphoid Stroma

A Rare Case of Primary Adenocarcinoma of the Gallbladder With Lymphoid Stroma

Critical Appraisal of Histologic Grading for Mucoepidermoid Carcinoma of Salivary Gland: Is an Objective Prognostic 2-tiered Grading System Possible?

Multiple 3-tiered grading systems exist for mucoepidermoid carcinoma (MEC), leading to controversial results on the frequency and prognostic values of each grade. We aimed to identify prognostic histologic factors and to evaluate grading schemes in this retrospective study of 262 resected primary head and neck MECs. The rate of nodal metastasis was 8.4%. Large tumor size, tumor fibrosis, infiltrative border, lymphovascular invasion, perineural invasion, atypical mitosis, mitotic index (MI) ≥4/2mm 2 (4/10HPFs), necrosis, and pT4 stage were associated with increased risk of nodal metastasis. The 5-year recurrence-free survival (RFS) was 95%. Significant prognostic factors for RFS included infiltrative border, tumor-associated lymphoid stroma, architectural patterns (macrocystic, microcystic, and noncystic), anaplasia, atypical mitosis, MI, necrosis, lymphovascular invasion, margin, pT stage, and tumor size. Nuclear anaplasia, high mitotic rate, and ≥25% microcystic component were significant independent prognostic factors on multivariate survival analysis. There was no significant difference between low-grade (LG) and intermediate-grade (IG) MECs in terms of risk of nodal metastasis and outcomes using all 4 known grading systems. Rather, high-grade MEC was consistently associated with an increased risk of nodal metastasis at presentation and decreased RFS and distant metastasis-free survival (DMFS) compared with the LG/IG MECs. We therefore recommend simplifying MEC grading to a 2-tiered grading scheme using MI and/or tumor necrosis. Using a 2-tiered grading, high-grade histology independently predict RFS, and is associated with a 25% risk of nodal metastasis, a 5-year RFS of 76%, and a 5-year DMFS of 76%, whereas LG MEC has a nodal metastasis rate of 7.0%, 5-year RFS of 97% and 5-year DMFS of 99%.

Resection of a micronodular thymoma with lymphoid stroma achieved by robot-assisted thoracic surgery (RATS): a case report

Resection of a micronodular thymoma with lymphoid stroma achieved by robot-assisted thoracic surgery (RATS): a case report

Abstract B006: Dissecting metabolic alterations of clear cell renal cell carcinomas one cell at a time

Abstract Pseudohypoxia-related metabolic alterations are known to exist in clear-cell renal cell carcinoma (ccRCC). Here we characterized single-cell metabolic pathways with the 10Xmultiome assay comparing metabolic and compositional shifts in tumor vs. normal-adjacent samples. We analyzed 57 tumor and 6 normal-adjacent samples from the Dartmouth Renal Tumors Biobank collected between 1994-2009. Samples were enzymatically disassociated and stored at -80 C until 10X multiome processing. RNA counts were extracted using Seurat, cell types were deconvolved using Azimuth, and 85 KEGG metabolic pathways were interrogated using scMetabolism scores. Linear mixed-effects models compared the metabolic scores in 10 cell lineages (juxtaglomerular apparatus, glomeruli, proximal tubule system, nephron loop, distal tubules, collecting ducts, lymphoid, myeloid, endothelia, and other stroma cells) between tumor and normal adjacent adjusting for sex, patient age, stage and grade as fixed-effects and donor, and year of collection, as random-effects. P-values were calculated using Satterthwaite's method. The mean age at diagnosis was 61.7 yrs (SD: 12.5), and 67% were stages I/II. 79,804 tumor and 5,967 normal-adjacent cells were analyzed. 34,318 cells were nephron epithelia (juxtaglomerular, glomeruli, renal tubules), 5,947 were collecting ducts, 18,959 were immune, 13,445 were endothelial, and 13,112 were other stromal cells. Out of 85 KEGG metabolic pathways, nine were prioritized based on the kidney cancer literature; glycolysis, oxidative phosphorylation, TCA cycle, fatty acid biosynthesis, glutamine/glutamate, arachidonic acids, phenylalanine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, and glutathione. When comparing vs. the corresponding normal adjacent cell type, in tumor cells: 1) glutamine/glutamate expression increased in lymphoid, endothelial, and stromal cells; 2) fatty acid biosynthesis increased in myeloid and reduced in lymphoid, collecting ducts-like, and nephron loop-like cells, 3) glutathione and glycolysis increased in glomeruli-like and nephron loops-like, 4) glycolysis increased in collecting ducts-like and endothelial, 5) oxidative phosphorylation and TCA cycle genes decreased in distal tubules-like, collecting ducts-like, and endothelia, 6) arachidonic acid metabolism increased in nephron loops-like and glomeruli-like, and 7) phenylalanine, tyrosine, and tryptophan biosynthesis decreased in nephron loops-like, distal tubules-like, and collecting ducts-like cells. Cell-specific metabolic shifts were observed between tumor and normal adjacent samples that cannot be explained only by sample heterogeneity or cell lineages. Oxidative phosphorylation and TCA cycle modifications were observed in tumor endothelia and cells resembling distal tubules and collecting ducts. Similarly, glutamate and fatty acid alterations were focused on tumor microenvironment immune cells. Further dissecting these findings will provide additional therapeutic avenues for newer targets, such as glutaminase inhibitors and combinations with current therapies. Citation Format: Lucas A. Salas, Ze Zhang, Laurent Perreard, Fred W. Kolling, Jason R. Pettus, Brock C. Christensen. Dissecting metabolic alterations of clear cell renal cell carcinomas one cell at a time [abstract]. In: Proceedings of the AACR Special Conference: Advances in Kidney Cancer Research; 2023 Jun 24-27; Austin, Texas. Philadelphia (PA): AACR; Cancer Res 2023;83(16 Suppl):Abstract nr B006.

Detection of Human Boca Virus in Gastric Adenocarcinoma.

Background: Gastric cancer is one of the most common cancers worldwide. Human bocavirus (HBoV), a recently isolated virus, has been investigated for its role in many respiratory and enteric diseases. Few studies have reported its presence in solid tumors, such as lung and colon cancers. The aim of this study was to detect the presence of the HBoV1 genome in gastric adenocarcinoma, which has not yet been evaluated. Methods: Formalin-fixed paraffin-embedded (FFPE) blocks of 189 gastric tumors and 50 blocks of non-tumor gastric tissue products from elective weight reduction operations were collected. DNA extraction and real-time polymerase chain reaction (PCR) were performed for HBoV1 detection. DNA sequencing was performed using ABI Genetic Analyzer series 3500. Results: The mean age of the patients was 60±13.33 years. Tumors were more common in males than females (2.5/1). HBoV1 PCR was positive in 34 (18%) cases of GC and 10 (20%) cases of chronic gastritis (P>0.05). There was no association between age, sex, stage, and histologic subtype of the tumor and HBoV1 positivity (P>0.05) in tumor samples. The rate of intestinal metaplasia and presence of lymphoid stroma were also not more frequent in HBoV1-positive tumors (P>0.05). Conclusion: The HBoV1 can be detected in a relatively high proportion of Iranian patients with gastric cancer (18%) with no predilection for specific subtypes and no association with the degree of lymphocytic infiltration. HBoV1 can also be observed in approximately 20% of chronic gastritis cases. Further comprehensive studies are needed to elucidate the role of HBoV1 in gastric cancer development.

Warthin-like papillary thyroid carcinoma: a case report and comprehensive review of the literature.

Papillary Thyroid Carcinoma (PTC) is the most frequent endocrine malignancy with a variety of histological presentations. Warthin-like Papillary Thyroid Carcinoma (WLPTC) is an uncommon neoplasm that is recognized as a distinct subtype of PTC in the WHO classification of thyroid tumors. In this report, we present a novel case of WLPTC in a female patient and provide an in-depth review of the available literature on its clinical, pathological, and therapeutic characteristics. A 27-year-old female patient was referred for neck swelling. Ultrasound showed two suspicious thyroid nodules leading to a thyroidectomy. She was diagnosed with intermediate-risk bifocal foci of classic PTC and WLPTC, arising from a background of chronic lymphocytic thyroiditis (CLT). This pT1b(m) N1b M0 malignancy was treated with adjuvant isotopic ablation and suppressive thyroxine therapy. The 1-year outcomes were favorable. It covered articles published from 1995 to 2022, by searching PubMed and Google Scholar using specific terms. Out of 148 articles reviewed by two authors, 25 relevant articles were selected, including 13 case reports and 12 case series. The study included 150 cases of WLPTC. Data related to clinical presentation, imaging, histological features, management, and outcomes, were extracted. The mean age of diagnosis was 39 years, with a female predominance. The most common clinical presentation was neck swelling. Thyroid autoimmunity was positive in 71.6% of patients. Lymph node metastases were present in 28% of cases, with no reported distant metastases. Overall, the outcomes were favorable. WLPTC shares similar clinical and radiological presentations as classic PTC. The hallmark histological features of WLPTC are papillae lined with oncocytic tumor cells with papillary nuclear changes and lymphoid stroma. WLPTC is almost constantly associated with CLT. The management of WLPTC aligns with that of classic PTC with comparable stage and risk category, often resulting in favorable outcomes.