OBJECTIVE:The use of molecular pathology is critical in diagnostics and theranostics. Today, cytological smears are utilized for molecular testing more often than ever. Accurate tumor cell percentage estimation is essential for reliable molecular testing, but its consistency remains uncertain. This study evaluates the reliability of tumor cell percentage estimations among an expert cytopathologist, a molecular cytopathologist, and a molecular pathologist. MATERIAL AND METHODS:Digital images from May-Grünwald-Giemsa (MGG)-stained smear slides of ten EBUS-guided mediastinal lymph node samples were selected. Five regions per slide were evaluated (50 areas from 10 patients). Three pathologists independently estimated tumor cell percentages using predefined categories (0-10%, 11-20%, 21-50%, etc.). Cells were also counted manually as the gold standard. RESULTS:The molecular cytopathologist (Observer 1 -) showed the highest consistency (Kappa = 0.69), followed by the expert cytopathologist (Observer 3 -, Kappa = 0.64), both demonstrating substantial agreement with the gold standard. The molecular pathologist (Observer 2 -) displayed moderate consistency (Kappa = 0.52). Agreement was most significant in the 71-100% category, aligning in over 95% of cases. The lowest value occurred in the 11-20% category. In this category, tumor proportions were frequently overestimated compared to the gold standard. CONCLUSION:Variability in tumor percentage estimations shows the need for standardized protocols and training. Substantial agreement was reached in specific categories. However, discrepancies in borderline cases highlight the importance of accurate assessments. More research is needed to improve estimation methods.

Background Preanalytical processes-including sample collection, fixation, and handling-significantly influence the integrity of nucleic acids, which in turn impacts the accuracy of next-generation sequencing (NGS)-based biomarker analyses. Though commonly utilized, cytological specimens remain underrepresented in studies evaluating preanalytical quality.Methods We retrospectively analyzed 1048 NGS tests performed between May 2019 and December 2022, encompassing cytological materials (smear slides and cell blocks), small/core biopsies, and resection specimens. Quality control (QC) was assessed using pre-sequencing cycle threshold (Ct) values and post-sequencing metrics such as fragment length, on-target unique fragments, deduplication ratio, and unique start.Results Overall, 22.9% of samples did not meet manufacturer Ct thresholds. The final QC failure rates were 12.4% for RNA and 3.5% for DNA. RNA QC failures were significantly more frequent in cytology and resection specimens compared to biopsies. However, post-sequencing analysis revealed that smear samples exhibited significantly higher median DNA and RNA fragment lengths compared to FFPE specimens, indicating superior nucleic acid preservation in samples that passed QC.Conclusion Cytological specimens are viable for NGS-based molecular testing, particularly when preanalytical variables are standardized and optimized. DNA quality from smears may even exceed that of FFPE samples, while RNA integrity remains more sensitive to preparatory conditions. These findings support the broader use of cytological materials in molecular diagnostics and highlight the need for tailored preanalytical workflows.

Automatic cell detection is a key task in digital pathology, where manual counting remains impractical due to its time-consuming nature and susceptibility to variability and error. Current deep learning approaches still have difficulty achieving accurate detection, particularly in images with crowded cell distributions. In such settings, capturing the global organization of cells within tissue becomes critical; however, the topological structure underlying cell arrangements is often ignored by existing models. To address these limitations, we propose topology-guided hard example mining (TG-HEM), a novel training strategy that incorporates topological constraints into the training of cell detection networks through loss reweighting. In contrast to pixel-centric HEM techniques, TG-HEM identifies challenging regions by quantifying topological discrepancies between ground truth and predicted cell distributions using persistent homology, rather than relying solely on local pixel-wise errors. By assigning higher importance to regions with larger topological inconsistencies and further emphasizing hard-to-learn pixels within these regions, the proposed approach guides backpropagation toward regions that reflect structural differences in cell distributions. This formulation enables HEM at both the region and pixel levels, allowing the network to better capture higher-order organization in crowded cell distributions. We evaluate TG-HEM across multiple network architectures and on two datasets: the publicly available BRCA-M2C dataset and our in-house KUCell dataset, which we release as part of this work. The experimental results show that the proposed TG-HEM approach consistently improves both cell counting and localization accuracy compared to existing HEM strategies. These improvements are achieved without introducing additional model complexity or inference-time overhead, and with only negligible impact on training time. The KUCell dataset is available at https://mysite.ku.edu.tr/cgunduz/downloads/KUCell, and the codes are available at https://github.com/caki35/TGHEM.

Introduction: Pancreatic ductal adenocarcinoma (PDAC) frequently requires neo-adjuvant therapy, leaving cytologic preparations – especially endoscopic ultrasound-guided fine-needle aspiration smears – as the only naïve tissue available for molecular testing. However, their applicability remains underappreciated due to limited data and concerns about specimen adequacy. This study aimed to evaluate the feasibility of performing molecular analysis on cytologic smears to detect targetable alterations in PDAC. Methods: Molecular analysis was conducted on 120 PDAC samples: 41 cytology specimens, 50 core biopsies, and 29 resections. KRAS mutations and homologous recombination repair gene alterations were assessed. Rapid on-site evaluation guided triage in all FNA cases. DNA and RNA isolations were performed, followed by quality control (QC) assessment and sequencing. Results: DNA isolation succeeded in 92/95 cases (97%), with a 100% success rate in cytologic specimens. RNA isolation passed QC in 71/84 samples (83%), with failures more common in smears (n = 8). KRAS mutations were detected in 71/85 patients (82%), with the highest detection in cytologic specimens (92%) compared to biopsies (78%) and resections (80%). Conclusion: Molecular testing is feasible and may even be more successful in cytologic smears than in biopsies or resections. High diagnostic yield and rapid processing favor their integration into routine molecular workflows. The superior performance of smears may relate to reduced stromal content and minimal processing delays. Cytologic specimens showed 100% DNA QC success, even when RNA QC failed, supporting their reliability. Although RNA analysis had a modest failure rate, its overall success suggests it can be incorporated into routine testing, particularly as fusion-driven targets gain clinical relevance.

OBJECTIVE:Loss of mismatch repair (MMR) protein expression, assessed via immunohistochemistry (IHC), and microsatellite instability (MSI) status, determined through molecular methods, are two tumor-agnostic predictive biomarkers for immunotherapy eligibility. However, there remains no consensus on the preferred testing method, nor on the type and extent of molecular testing required for optimal patient selection. This study investigates the correlation between MMR protein loss detected by IHC and MSI status identified through next-generation sequencing (NGS) to evaluate the concordance and potential complementary roles of these methods. MATERIAL AND METHODS:A total of 139 tumor samples were analyzed for MSI using NGS. The cohort included colorectal carcinoma (n=51), pancreatic ductal adenocarcinoma (n=22), cholangiocarcinoma (n=9), non-small cell lung carcinoma (n=6), adenoid cystic carcinoma (n=6), gastric adenocarcinoma (n=6), high-grade serous ovarian carcinoma (n=5), and 34 other tumor types. IHC was performed to assess MLH1, MSH2, MSH6, and PMS2 protein expression. The correlation between MSI status and MMR protein loss was evaluated. RESULTS:Twelve tumors (8.6%) were classified as MSI-High (microsatellite instable). Among them, ten exhibited MMR protein loss, whereas two MSI-High tumors (a mucinous adenocarcinoma of omental origin and a mucinous colon adenocarcinoma) retained MMR protein expression. No MMR-deficient tumors were identified as MSI-Low (microsatellite stable/MSS). CONCLUSION:A strong correlation exists between IHC-based MMR loss and NGS-based MSI detection. IHC remains widely used due to its accessibility and cost-effectiveness, whereas NGS offers higher accuracy and broader genomic insights. With its ability to detect multiple alterations simultaneously, NGS is particularly valuable when tissue is scarce. Combining both methods can improve diagnostic accuracy and guide optimal immunotherapy selection.

BACKGROUND:High-quality RNA is essential for accurate molecular testing. This study evaluates the impact of cytological preparation techniques (May-Grünwald-Giemsa [MGG], Papanicolaou [PAP], Diff-Quik, and air-dried) on RNA quality in smear slides. METHODS:A total of 182 smears were prepared from fresh surgical specimens of 26 patients using seven different techniques. RNA was isolated, reverse-transcribed, and analyzed using quantitative polymerase chain reaction (qPCR). RNA quality was assessed using ΔCt (ΔCt = 45 - Ct, cycle threshold), where higher ΔCt indicates better RNA quality. RESULTS:RNA quality, measured by ΔCt, showed clear differences (p < .001) in-between preparation methods, whereas RNA concentration did not differ significantly among smear types (p = .07). MGG-stained smears (both film- and coverslip-mounted) demonstrated the highest and most consistent ΔCt values. PAP-stained smears yielded the lowest ΔCt values, indicating the poorest RNA quality. Air-dried unstained smears showed highly variable ΔCt values and frequent amplification failures. Diff-Quik preparations had intermediate performance. Mounting method (film vs. coverslip) did not significantly affect RNA quality. CONCLUSION:Among cytology smear techniques, MGG provided the best RNA preservation, PAP the worst, and air-dried slides yielded inconsistent results. These findings highlight the critical role of smear preparation in preserving RNA for molecular testing, especially RNA-based next-generation sequencing.

Cell detection and segmentation are integral parts of automated systems in digital pathology. Encoder-decoder networks have emerged as a promising solution for these tasks. However, training of these networks has typically required full boundary annotations of cells, which are labor-intensive and difficult to obtain on a large scale. However, in many applications, such as cell counting, weaker forms of annotations--such as point annotations or approximate cell counts--can provide sufficient supervision for training. This study proposes a new mixed-supervision approach for training multitask networks in digital pathology by incorporating cell counts derived from the eyeballing process--a quick visual estimation method commonly used by pathologists. This study has two main contributions: (1) It proposes a mixed-supervision strategy for digital pathology that utilizes cell counts obtained by eyeballing as an auxiliary supervisory signal to train a multitask network for the first time. (2) This multitask network is designed to concurrently learn the tasks of cell counting and cell localization, and this study introduces a consistency loss that regularizes training by penalizing inconsistencies between the predictions of these two tasks. Our experiments on two datasets of hematoxylin-eosin stained tissue images demonstrate that the proposed approach effectively utilizes the weakest form of annotation, improving performance when stronger annotations are limited. These results highlight the potential of integrating eyeballing-derived ground truths into the network training, reducing the need for resource-intensive annotations.

Background:Desmoplastic infantile ganglioglioma/astrocytoma (DIG/DIA) is a rare, low-grade tumor of infants. They are usually composed of a mixed astrocytic and neuronal component with desmoplastic stroma and embryonal-looking areas. Despite some recent reports, clinical, morphological and molecular features of DIG/DIAs are still not well characterized. Here, we present a series of 8 DIG/DIA cases. Methods:Hacettepe University and Koc University Hospital, Departments of Pathology, databases were screened for DIG/DIA. Eight patients were identified. All the slides were reevaluated, and patients' clinical data were obtained. All cases were tested for BRAF V600 mutation and 3 BRAF V600 wild-type cases were sequenced. Results:Median age at the diagnosis was 5.5 months (4-30 months). The female to male ratio was 6:2. Two cases recurred. Four cases showed BRAF p. V600 mutation. Of those BRAF p. V600 wild-type cases, one harbored TMEM106B::BRAF fusion, described for the first time in a DIG/DIA case. Conclusions:DIG/DIA is a low-grade tumor seen in early childhood and characterized by an indolent clinical course. The most common molecular signature of these tumors is BRAF alterations, including rearrangements. The primary differential diagnosis is infant-type hemispheric glioma and given the similarities, pathologists must remain careful to ensure accurate diagnosis.

Background PD-L1 expression guides immunotherapy decisions in non small cell lung cancer (NSCLC), yet sample type can impact assessment accuracy. This study aimed to compare PD-L1 expression between small (biopsies, cell blocks) and large (resection) NSCLC samples, assess interobserver variability, and examine whether PD-L1 scoring trends remained stable over a multi-year period. Methods A retrospective analysis was conducted on 494 NSCLC patients tested for PD-L1 (Ventana SP263) between 2018 and 2022. Sample type, tumor subtype, PD-L1 tumor proportion score (TPS), and reporting pathologist were recorded. Interobserver variability was analyzed based on routine diagnostic reports from different pathologists evaluating non-overlapping patient cohorts. Additionally, a subset of 43 patients had matched cell block and resection specimens collected from the same tumor, allowing direct comparison between preparations. Results Among the 494 NSCLC specimens, 152 were large and 342 were small samples. TPS results showed 112 samples (22%) with TPS ≥ 50%, 163 (34%) with TPS 1%–49%, and 219 (44%) with TPS < 1%. No significant differences in TPS categories were observed between cell blocks and tissue samples (p = 0.176) or between small and large samples (p = 0.326). TPS distributions across different pathologists (p = 0.260) and years (p = 0.250) remained consistent. In the matched 43 specimens, TPS concordance between cell block and resection was high (κ = 0.892). Conclusion Small biopsies and cell blocks provide reliable PD-L1 results comparable to resection specimens, supporting their use for PD-L1 testing in clinical settings to enhance timely immunotherapy access for NSCLC patients.

OBJECTIVES:We present the first study validating the recent Dako ALK assay (clone OTI1A4, in vitro diagnostic) for detecting ALK rearrangements in lung adenocarcinoma.METHODS:Lung adenocarcinoma cases between 2011 and 2023 were retrospectively collected to create a cohort of 203 samples. Cases were stained with Dako ALK OTI1A4 and Ventana ALK D5F3 and reviewed by 3 pathologists independently. Correlation between assays, including their sensitivity and specificity, was evaluated.RESULTS:The cohort (n = 203) consisted of resections, core needle biopsies, and cell blocks. Agreement between Dako ALK OTI1A4 and Ventana ALK D5F3 assays was "almost perfect," with κ = 0.89. The sensitivity and specificity of the Dako ALK OTI1A4 assay were 93.3% and 96%, respectively, in a subgroup of 55 molecularly confirmed cases (n = 30 with and n = 25 without ALK rearrangement).CONCLUSIONS:Immunohistochemistry-based assays provide a valid and reasonably priced alternative, especially in settings where molecular confirmatory tests are neither offered nor accessible. Given high interassay and molecular concordance, we propose that the novel Dako OTI1A4 assay can be reliably used to identify cases with ALK rearrangement.

Medical institutions continuously create a substantial amount of data that is used for scientific research. One of the departments with a great amount of archived data is the pathology department. Pathology archives hold the potential to create a case series of valuable rare entities or large cohorts of common entities. The major problem in creation of these databases is data extraction which is still commonly done manually and is highly laborious and error prone. For these reasons, we offer using large language models to overcome these challenges. Ten pathology reports of selected resection specimens were retrieved from electronic archives of Koç University Hospital for the initial set. These reports were de-identified and uploaded to ChatGPT and Google Bard. Both algorithms were asked to turn the reports in a synoptic report format that is easy to export to a data editor such as Microsoft Excel or Google Sheets. Both programs created tables with Google Bard facilitating the creation of a spreadsheet from the data automatically. In conclusion, we propose the use of AI-assisted data extraction for academic research purposes, as it may enhance efficiency and precision compared to manual data entry.

BACKGROUND:Cytomorphological evaluation of tissue touch imprints during rapid on-site evaluation or intraoperative pathology consultation has crucial value. However, literature on their utility for molecular testing is limited. In this study, we emphasize a further benefit of touch imprint slides and scrutinize our institutional experience on their use in molecular testing, specifically next generation sequencing (NGS).MATERIALS AND METHODS:NGS-based reports (2019-2023) of Koç University Hospital were retrospectively analyzed and circumstances in which sequencing was conducted on touch imprint slides were retrieved (n = 18). Type/location of the biopsy, diagnosis, results, and quality metrics were recorded.RESULTS:Touch imprints were addressed when they harbored more neoplastic cells compared with permanent biopsies, when suboptimal fixation mitigated deoxyribonucleic acid/ribonucleic acid (DNA/RNA) yield in resections or when the sample was obtained from bone and required decalcification. Diagnoses were diverse, namely non-small-cell lung cancer, gastric adenocarcinoma, glial tumor, Ewing sarcoma, and carcinoma of unknown primary. The percentage of tumor cells on slides stretched between 15% and 70%. Molecular findings ranged from KRAS mutations to TRIM1::NTRK2 and EWSR::FLI1 fusions. For five cases, sequencing did not yield any alteration, one study was not completed because it did not yield high-quality RNA.CONCLUSION:Touch imprint slides provide a reliable alternative, especially when neoplastic cells are scarce in permanent biopsies or decalcification deters nucleic acid quality. Based on our experience, we suggest making touch imprints on a routine basis, especially for every bone biopsy. Once digitally scanned duplicates are made, original slides can be safely used for DNA-/RNA-based molecular studies.

The guidelines recently recognized the intra-ampullary papillary tubular neoplasm (IAPN) as a distinct tumor entity. However, the data on IAPN and its distinction from other ampullary tumors remain limited. A detailed clinicopathologic analysis of 72 previously unpublished IAPNs was performed. The patients were: male/female=1.8; mean age=67 years (range: 42 to 86 y); mean size=2.3 cm. Gross-microscopic correlation was crucial. From the duodenal perspective, the ampulla was typically raised symmetrically, with a patulous orifice, and was otherwise covered by stretched normal duodenal mucosa. However, in 6 cases, the protrusion of the intra-ampullary tumor to the duodenal surface gave the impression of an "ampullary-duodenal tumor," with the accurate diagnosis of IAPN established only by microscopic correlation illustrating the abrupt ending of the lesion at the edge of the ampulla. Microscopically, the preinvasive component often revealed mixed phenotypes (44.4% predominantly nonintestinal). The invasion was common (94%), typically small (mean=1.2 cm), primarily pancreatobiliary-type (75%), and showed aggressive features (lymphovascular invasion in 66%, perineural invasion in 41%, high budding in 30%). In 6 cases, the preinvasive component was pure intestinal, but the invasive component was pancreatobiliary. LN metastasis was identified in 42% (32% in those with ≤1 cm invasion). The prognosis was significantly better than ampullary-ductal carcinomas (median: 69 vs. 41 months; 3-year: 68% vs. 55%; and 5-year: 51% vs. 35%, P =0.047). In conclusion, unlike ampullary-duodenal carcinomas, IAPNs are often (44.4%) predominantly nonintestinal and commonly (94%) invasive, displaying aggressive features and LN metastasis even when minimally invasive, all of which render them less amenable to ampullectomy. However, their prognosis is still better than that of the "ampullary-ductal" carcinomas, with which IAPNs are currently grouped in CAP protocols (while IAPNs are kindreds of intraductal tumors of the pancreatobiliary tract, the latter represents the ampullary counterpart of pancreatic adenocarcinoma/cholangiocarcinoma).

Objective: This study aims to identify activating mutations in the epidermal growth factor receptor (EGFR) gene in patients with non-small cell lung cancer (NSCLC) and to evaluate their correlation with responses to EGFR-tyrosine kinase inhibitors (TKI) treatment. This study aims to identify activating mutations in the epidermal growth factor receptor (EGFR) gene in patients with non-small cell lung cancer (NSCLC) and to evaluate their correlation with responses to EGFR-tyrosine kinase inhibitors (TKI) treatment. We conducted a comparative analysis of Real-Time PCR and immunohistochemistry to detect EGFR mutation status in non-small cell lung cancer patients, focusing on the sensitivity, specificity, and predictive values of immunohistochemistry.Material and Method: We evaluated 788 non-small cell lung cancer samples which were analyzed for EGFR mutation status by RT-PCR. We detected 126 EGFR mutated cases among these patients. We evaluated mutation-specific EGFR immunohistochemistry directed towards the exon 19 deletions (15 bp E746-A750) and exon 21 point mutation (L858R) to the 47 EGFR mutated patients histologic material and cell blocks of cytologic specimens.Results: 32 of the 47 cases (68%) had exon 19 deletion, 14 of them (30%) had point mutation in exon 21, and one of them (2%) showed exon 18 mutation. EGFR exon 19 (15 bp E746-A750 deletion) antibody showed a sensitivity of 100%, specificity of 40%, negative predictive value of 100%, and positive predictive value of 78%. The sensitivity of the exon 21 (L858R point mutation) antibody was 93%, specificity was 91%, negative predictive value was 97% and positive predictive value was 82%.Conclusion: Our investigation indicates that mutation-specific EGFR immunohistochemistry has demonstrated a notable sensitivity and specificity for exon 21. However, while sensitive, the exon 19 (15 bp E746-A750 deletion) antibody lacked specificity. While positive immunohistochemical staining may suggest the presence of an EGFR mutation, making the patient potentially eligible for TKI treatment, it should not be the sole determinant. If immunohistochemistry results are negative, it is essential to resort to molecular tests to ensure accurate diagnosis and appropriate therapeutic guidance. With evolving diagnostic landscapes, it is crucial to harness both IHC and molecular techniques judiciously for optimal patient care.

Malignant peritoneal mesothelioma (MPM) is an exceptionally rare tumor type. Although some somatic/germline genetic alterations including BAP1 loss have been identified in some cases, the molecular properties of MPMs are remained poorly understood. In recent years, anaplastic lymphoma kinase (ALK) gene rearrangement was revealed in a subset of (3.4%) MPMs. Low-grade serous carcinomas (LGSCs) are a rare subtype of ovarian carcinoma and have some morphologic and immunophenotypic overlapping features with MPMs and this may cause misdiagnosis in daily practice. Here, we report a case of 18-year-old women with STRN-ALK-rearranged MPM and no previous exposure to asbestos. This case was presented with bilateral pelvic masses and histologically was displaying pure papillary morphology with mild-to-moderate nuclear atypia, psammoma bodies, and diffuse PAX8 expression as LGSCs. With the detection of ALK alteration in some of the MPMs, a targeted treatment option has emerged for these unusual tumor types.

BACKGROUND:Vascular endothelial growth factor (VEGF) plays a pivotal role in the pathogenesis of autoimmune chronic inflammatory conditions and papillary thyroid carcinoma (PTC). We hypothesized that, as VEGF expression is increased both in PTC and in lymphocytic thyroiditis (LT), it may stimulate the development of PTC in patients with LT. To evaluate this, we examined both tumor and adjacent non-tumoral tissues of PTC patients with and without LT.METHODS:A total of 50 patients with PTC (52.50±7.41 years) and 17 patients with nodular goiter (NG) (50.47±10.38 years) were included in the study. According to the presence of LT, patients with PTC were further divided into two groups. Immunohistochemical analyses of VEGF were conducted in all patients and for PTC patients, both tumor tissue and adjacent non-tumoral tissue were evaluated.RESULTS:The scores for intensity of staining and percentage of labeled thyrocytes for VEGF were found to be significantly higher in the PTC patients than in the NG patients (P<0.001, P<0.001, respectively). The tumor tissue revealed similar scores for PTC patients with LT and without LT. However, the scores in adjacent non-tumoral tissue were higher in PTC patients with LT than in patients without LT (P=0.004, P=0.01, respectively).CONCLUSIONS:To the best of our knowledge, our results are the first to demonstrate that the expression of VEGF in adjacent non-tumoral tissue were higher in PTC patients with LT than in those without, which shows a possible role of VEGF expression in the progression of PTC in the presence of LT.

BACKGROUND:Mucoepidermoid carcinoma (MEC) showing Warthin's tumor (WT)-like features is a low-grade malignancy which should be differentiated from WT. Morphological features may be distinctly different in each case, causing diagnostic difficulties.CASE PRESENTATION:Three cases were presented and discussed with their morphologies. All cases that presented with a mass in the parotid gland went to parotidectomy, and all had preoperative fine-needle aspirations (FNAs). Case 1 was a 16-year-old female; FNA was suggestive of WT and initially interpreted as WT histologically. Case 2 was a 27-year-old male; FNA was interpreted as noninformative due to the presence of cyst fluid only. Case 3 was a 53-year-old male and cytologically was found to be suspicious for MEC which contained squamous and goblet cells on a mucoid background. On histopathological examination, case 2 and case 3 were morphologically consistent with low-grade MEC with WT-like features. Prominent lymphoid stroma and the cystic pattern were the characters of these tumors. Case 1 had the classical WT appearance with some mucinous and squamous metaplasia which could only be interpreted as MEC after the detection of MAML2 rearrangement by FISH. The other 2 showed either focal or relatively diffuse usual low-grade MEC findings, and case 3 was also confirmed by MAML2 rearrangement.CONCLUSION:Cytological and histopathological features revealed a spectrum. Differentiating WT-like MECs from ordinary WTs may be challenging. On the one end of the spectrum, they may look very much like WT, and on the other end, even though usual MEC features are present, still, WT-like appearance may pose diagnostic difficulty. Showing MAML2 rearrangement in these cases is very helpful. The presence of mucinous and squamous cells in an otherwise WT-like looking tumor should be alarming for MEC, and if possible, each case should be analyzed for MAML2 rearrangement.

OBJECTIVE:Lymph node metastasis is the most important factor both in the selection of treatment since many alternatives have been created in recent years, and in the evaluation of prognosis in lung cancer. The most unpredictable cause of lymph node false positivity in fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is anthracosis. The aim of this study is to compare 18F-FDG PET/CT texture information of anthracotic (ALN) and metastatic (MLN) lymph nodes, after re-evaluation of the cytological samples obtained from anthracotic lymph nodes by EBUS-TBNA.SUBJECTS AND METHODS:Ninety nine patients, 78 of whom had primary lung cancer were included in the study. Two hundred and three lymph nodes from 99 patients sampled by EBUS-TBNA and diagnosed cytologically as ALN or MLN were evaluated retrospectively. All ALN were classified as grades 1, 2 and 3 cytologically. Volume of interest (VOI) of 203 lymph nodes was re-drawn and maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) values were recorded.RESULTS:There was a statistically significant difference in MTV and TLG values in MLN and all ALN grades. However, only grade 1-2 ALNs could be differentiated from MLNs with SUVmax, and no statistically significant difference was found in grade 3 ALN and MLN. Metabolic tumor volume and TLG values over 4.10cm3 and 26.57 showed 60% and 59% sensitivity and 83% and 94 specificity respectively for the identification of MLN.CONCLUSION:The contribution of MTV and TLG values of 18F-FDG PET/CT to the differential diagnosis of ALN is much more valuable than SUVmax values, especially for grade 3 anthracosis. It was thought that cytological reporting of only grade 3 ALN could make a better contribution to the 18F-FDG PET/CT evaluation analysis.

Background/Aim: Ischemia/reperfusion (I/R) injury occurs during breast cancer surgery, especially those involving a modified radical mastectomy, lumpectomy, and axillary lymph node dissection. Tissue damage and stress due to I/R alter immune system functions, especially those of the myeloid cells. The immunologic impact of this I/R injury on myeloid-derived cancerous cells remains unknown. We sought to investigate the effect of I/R injury in the extremity close the breast tumor location on myeloid cell population in the liver and liver metastasis. Methods: 4T1 breast tumors were created in the left inguinal breast region of the experimental animals. When the tumor reached 0.5 cm in diameter, ischemia was produced on the left down-extremity for 90 min and reperfusion was induced for short (3 days), middle (7 days), and long terms (14 days). At the end of the reperfusion period, proximal limbs and livers were harvested. The limb and liver samples were histopathologically examined with H&E staining. Immune cell percentages were determined in the liver by flow cytometry. Results: There was an increase in muscle fiber degeneration and disorganization in the I/R induced proximal legs on days 3 and 7 of I/R in both tumor free and tumor bearing animals with a further impact in tumor bearing mice. Even though I/R injury did not affect tumor metastasis to the liver, it had an impact on liver myeloid cell percentages in both tumor free and tumor bearing animals. Additionally, tumor bearing mice demonstrated higher myeloid cell percentages in both the pre-I/R and post-I/R experimental groups. There was a remarkable change in the levels of granulocytic, and monocytic myeloid cells and macrophages due to the I/R injury. Conclusion: With the formation of short-term I/R injury in a distant site, tumor development and/or seeding to metastasis sites after surgery could be prevented. This study contributes to the understanding of the inflammatory process after I/R injury occurring during interventions.