Dong Hoon Shin

Invasive mucinous adenocarcinoma (IMA) of the lung is a distinct subtype of lung adenocarcinoma with unique clinicopathologic features; however, its histogenesis remains incompletely understood. Although mucinous metaplasia has been suspected as a precursor lesion, direct molecular evidence supporting this progression is limited. In this study, we applied morphology‐guided spatial transcriptomics to investigate epithelial lineage relationships across the mucinous spectrum of lung lesions. Formalin‐fixed, paraffin‐embedded lung tissues from 26 patients were analyzed using the GeoMx digital spatial profiling platform. A total of 118 cytokeratin‐positive regions of interest representing normal bronchioles, bronchiolar metaplasia, mucinous metaplasia, mucinous dysplasia, IMA, nonmucinous terminal respiratory unit–type adenocarcinoma, squamous metaplasia/dysplasia, and squamous cell carcinoma were profiled. Spatial transcriptomic data were integrated with two independent public cohorts and mapped to the Human Lung Cell Atlas for epithelial cell‐type assignment. Unsupervised clustering identified a distinct mucinous cluster comprising IMA and most mucinous dysplasia regions, characterized by enrichment of gastric‐type differentiation markers, including MUC5AC , MUC6 , TFF1 , TFF2 , and CLDN18 . Label‐transfer analysis demonstrated that mucinous metaplasia and dysplasia were predominantly associated with club and goblet cell identities, whereas IMAs showed enrichment of club and goblet signatures. In contrast, nonmucinous adenocarcinomas consistently aligned with alveolar type 2 cell identity across all datasets. Immunohistochemistry confirmed uniform CLDN18 expression in IMAs and its absence in nonmucinous adenocarcinomas. These findings provide spatial transcriptomic evidence supporting a club cell–associated mucinous pathway in lung tumorigenesis and identify CLDN18 as a defining molecular feature of IMA. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Introduction and importance: The coexistence of sclerosing pneumocytoma (SP) and typical carcinoid (TC) within the same lesion is extremely rare. Case presentation: The patient is a 66-year-old woman who was incidentally found to have a 2.2 cm nodule in the right upper lobe during a routine physical examination using computed tomography. A wedge resection of the right upper lobe via thoracoscopy was performed, confirming that the tumor was a mixture of SP and TC by immunohistochemistry. No tumor recurrence or metastasis was observed during the follow-up period of 15 months. Clinical discussion: A case of SP and TC coexisting in the same mass caused the diagnostic challenges and required clinicopathologic correlation analysis because of the rarity. Conclusion: We reviewed the relevant literature to enhance our understanding of the pathologic diagnosis and pathogenesis of this case and to provide valuable insights for the differential diagnosis of pulmonary nodules.

Background: Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods.Methods: A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2.Results: All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%).Conclusions: Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.

Background/Objectives: This study evaluated the impact of fluorescence lymph node mapping (FLNM) using indocyanine green (ICG) on the diagnostic accuracy of preoperative computed tomography (CT) in right-sided colon cancer. Methods: A total of 218 patients who underwent laparoscopic right hemicolectomy with D3 lymph node dissection (LND) were analyzed: 86 patients in the FLNM group and 132 in the conventional surgery group. The FLNM technique allowed for enhanced intraoperative visualization of lymph node (LN) and more precise dissection, improving the identification of metastatic LNs. The diagnostic value of preoperative CT staging was assessed in both the FLNM and control groups by calculating the apparent prevalence, true prevalence, sensitivity, specificity, positive predictive value (PPV), negative predictive value, positive likelihood ratio (PLR), negative likelihood ratio, false positive and false negative proportions, and accuracy. Results: FLNM increased the accuracy of CT staging for detecting D3 LN metastasis in advanced cancer cases, with a higher PPV, PLR, and accuracy. In the FLNM group, the false-positive rate was significantly reduced, and the specificity was higher compared to the control group. Multivariate analysis identified FLNM as an independent factor associated with improved D3 LN metastasis detection. These findings suggest that incorporating FLNM into surgical procedures enhances the diagnostic value of preoperative CT by improving the precision of LND, particularly in patients with advanced colon cancer. Conclusions: The use of FLNM for D3 LND enhances the diagnostic accuracy of cN staging in right-sided colon cancer by improving surgical precision.

Background and Objectives: This study aimed to explore biomarker change after NAC (neoadjuvant chemotherapy) and to investigate biomarker expression as a prognostic factor in patients with residual disease (RD) after NAC. Materials and Methods: We retrospectively evaluated 104 patients with invasive breast cancer, who underwent NAC and surgery at Pusan National University Hospital from 2015 to July 2022. The expression of the biomarker was assessed, and the overall survival (OS) and disease-free survival (DFS) were investigated. Results: After NAC, 24 patients (23.1%) out of 104 total patients had a pathological complete response (pCR). We found that changes in at least one biomarker were observed in 41 patients (51.2%), among 80 patients with RD. In patients with RD after NAC (n = 80), a subtype change was identified in 20 patients (25.0%). Any kind of change in the HER2 status was present 19 (23.7%) patients. The hormone receptor (HR)+/HER2+ subtype was significantly associated with better disease-free survival (DFS) (HR, 0.13; 95% CI, 0.02–0.99; p = 0.049). No change in p53 was associated with better DFS, and negative-to-positive change in p53 expression after NAC was correlated with worse DFS (p < 0.001). Negative-to-positive change in p53 was an independent, worse DFS factor in the multivariate analysis (HR,18.44; 95% CI, 1.86–182.97; p = 0.013). Conclusions: Biomarker change and subtype change after NAC were not infrequent, which can affect the further treatment strategy after surgery. The expression change of p53 might have a prognostic role. Overall, we suggest that the re-evaluation of biomarkers after NAC can provide a prognostic role and is needed for the best decision to be made on further treatment.

The progression of idiopathic pulmonary fibrosis (IPF) is diverse and unpredictable. We identified and validated a new biomarker for IPF progression. To identify a candidate gene to predict progression, we assessed differentially expressed genes in patients with advanced IPF compared with early IPF and controls in three lung sample cohorts. Candidate gene expression was confirmed using immunohistochemistry and Western blotting of lung tissue samples from an independent IPF clinical cohort. Biomarker potential was assessed using an enzyme-linked immunosorbent assay of serum samples from the retrospective validation cohort. We verified that the final candidate gene reflected the progression of IPF in a prospective validation cohort. In the RNA-seq comparative analysis of lung tissues, CD276, COL7A1, CTSB, GLI2, PIK3R2, PRAF2, IGF2BP3, and NUPR1 were up-regulated, and ADAMTS8 was down-regulated in the samples of advanced IPF. Only CTSB showed significant differences in expression based on Western blotting (n = 12; p < 0.001) and immunohistochemistry between the three groups of the independent IPF cohort. In the retrospective validation cohort (n = 78), serum CTSB levels were higher in the progressive group (n = 25) than in the control (n = 29, mean 7.37 ng/mL vs. 2.70 ng/mL, p < 0.001) and nonprogressive groups (n = 24, mean 7.37 ng/mL vs. 2.56 ng/mL, p < 0.001). In the prospective validation cohort (n = 129), serum CTSB levels were higher in the progressive group than in the nonprogressive group (mean 8.30 ng/mL vs. 3.00 ng/mL, p < 0.001). After adjusting for baseline FVC, we found that CTSB was independently associated with IPF progression (adjusted OR = 2.61, p < 0.001). Serum CTSB levels significantly predicted IPF progression (AUC = 0.944, p < 0.001). Serum CTSB level significantly distinguished the progression of IPF from the non-progression of IPF or healthy control.

김진우, et al. J Korean Soc Radiol. 2024 Sep;85(5):954-959. https://doi.org/10.3348/jksr.2024.0042

Rationale: Small bowel diaphragm disease (SBDD) is a rare case, caused by long-term administration of nonsteroidal anti-inflammatory drugs (NSAIDs). The circumferential diaphragm in the lumen of small bowel causing mechanical obstruction is the characteristic finding. Patient concerns: A 74-year-old male was transferred to Pusan National University Yangsan Hospital (PNUYH) due to abdominal pain lasting for 2 months. He was treated in the local medical center (LMC) with Levin tube insertion and Nil Per Os (NPO) but showed no improvement. Diagnosis: According to abdomen-pelvis computed tomography (CT) result, small bowel obstruction due to the adhesion band was identified, showing dilatation of the small bowel with abrupt narrowing of the ileum. Interventions: Laparoscopic exploration was done but failed to find an adhesion band. An investigation of the whole small bowel was done with mini-laparotomy. At the transitional zone, the intraluminal air could not pass so the segmental resection of small bowel including the transitional zone and end-to-end anastomosis was done. Outcomes: After surgery, every laboratory finding recovered to the normal range in 4 days, but the patient’s ileus lasted for 8 days. The patient’s symptoms were relieved after defecation, he was discharged on postoperative day 10. Lessons: For patients who show mechanical obstruction without an operation history but with long-term administration of NSAIDs, the clinicians should suspect small bowel diaphragm disease.

Background: The distinction between D3 lymph nodes and actual lymphatic pathways in primary tumors can be difficult during surgery, making it challenging to confirm the completeness of D3 lymph node dissection. Fluorescence lymph node mapping (FLNM) is a promising method for lymph node visualization. Purpose: This study aimed to assess whether FLNM enhances the effectiveness of D3 lymph node dissection in patients with right-sided colon cancer. Methods: Endoscopic submucosal indocyanine green injection were performed on the distal margin of the colon cancer. In an FLNM group, the lymphatic drainage pathway and distribution of D3 lymph nodes were explored. Pathological evaluations were conducted for the fluorescent D3 and non-fluorescent D3 lymph nodes. Results: The FLNM group showed a significantly higher number of harvested lymph nodes in the D3 area. In stage III patients, the proportion of D3 lymph node metastasis was significantly higher in the FLNM group. The harvested D3 lymph node count showed a proportional correlation with a metastatic lymph node count of up to 15. Conclusion: FLNM could be considered a promising new strategy to potentially increase harvested D3 lymph node counts in colon cancer surgery.

2023 International Conference on Solid State Devices and Materials ,Highly Reliable Dual-mode Memristor with Digital and Analog Features