Objectives: Intradiscal steroid injection (ISI) use has been proven as a low-risk and rapid treatment for disc degeneration disease (DDD). However, the histological effects of steroids on human discs remain poorly understood. The purpose of this study is to investigate whether ISI induces histologic degeneration of the disc. Methods: In this study, a histological analysis was carried out on the nucleus pulposus obtained from 150 patients who underwent posterior lumbar interbody fusion. Among these individuals, 59 received ISI before the surgery, while 91 did not. After staining with hematoxylin and eosin, the histological classification was performed based on chondrocyte proliferation (C1, C2, and C3) and granular matrix change (M1 and M2). Logistic regression analysis was used to identify the main factors influencing chondrocyte proliferation and granular matrix change.Additionally, histological differences between the ISI group and the non-ISI group were analyzed. Results: Chondrocyte proliferation and granular matrix changes were not significantly different between the ISI and non-ISI groups. The logistic regression analysis indicated that age is the most significant risk factor for both chondrocyte proliferation (P = 0.02) and granular matrix changes (P < 0.01). Conclusions The most crucial factor in disc degeneration is age. ISI does not accelerate the histological degeneration of chondrocyte proliferation and granular matrix. Therefore, the ISI could be considered as a histologically safe alternative in patients with DDD.

Desmoplastic Spitz nevus is a rare variant of Spitz nevus characterized by predominantly spindle-shaped or epithelioid nevus cells within the fibrotic stroma that can be confused with fibrous lesions. A 43-year-old woman presented with a 1-cm-sized dome-shaped papule on the dorsum of her left foot. The lesion showed histopathological features of a desmoplastic Spitz nevus with structures that resemble adenoma. Immunohistochemical staining was positive for S-100 protein, Melan-A, and SOX-10. Herein, we report this case because desmoplastic Spitz nevus is rare and can lead to confusion regarding the diagnosis of adnexal neoplasms.

Background: Next-generation sequencing (NGS) is an approved test to select patients for BRAF V600E targeted therapy in Korea. However, the high cost, long turnaround times, and the need for sophisticated equipment and skilled personnel limit the use of NGS in daily practice. Immunohistochemistry (IHC) is a rapid and relatively inexpensive assay available in most laboratories. Therefore, in this study, we evaluate the usefulness of BRAF VE1 IHC in terms of predictive value and interobserver agreement in non–small cell lung cancers (NSCLCs). Methods: A total of 30 cases with known BRAF mutation status were selected, including 20 cases of lung adenocarcinomas, six cases of colorectal adenocarcinomas, and four cases of papillary thyroid carcinomas. IHC for BRAF V600E was carried out using the VE1 antibody. Fifteen pathologists independently scored both the staining intensity and the percentage of tumor cell staining on whole slide images. Results: In the lung adenocarcinoma subset, interobserver agreement for the percentage of tumor cell staining and staining intensity was good (percentage of tumor cell staining, intraclass correlation coefficient = 0.869; staining intensity, kappa = 0.849). The interobserver agreement for the interpretation using the cutoff of 40% was almost perfect in the entire study group and the lung adenocarcinoma subset (kappa = 0.815). Sensitivity, specificity, positive predictive value, and negative predictive value of BRAF VE1 IHC were 80.0%, 90.0%, 88.9%, and 81.8%, respectively. Conclusions BRAF VE1 IHC could be a screening test for the detection of BRAF V600E mutation in NSCLC. However, further studies are needed to optimize the protocol and to establish and validate interpretation criteria for BRAF VE1 IHC.

Molecular biomarker testing is the standard of care for non–small cell lung cancer (NSCLC) patients. In 2017, the Korean Cardiopulmonary Pathology Study Group and the Korean Molecular Pathology Study Group co-published a molecular testing guideline which contained almost all known genetic changes that aid in treatment decisions or predict prognosis in patients with NSCLC. Since then there have been significant changes in targeted therapies as well as molecular testing including newly approved targeted drugs and liquid biopsy. In order to reflect these changes, the Korean Cardiopulmonary Pathology Study Group developed a consensus statement on molecular biomarker testing. This consensus statement was crafted to provide guidance on what genes should be tested, as well as methodology, samples, patient selection, reporting and quality control.

Background: Previously developed prediction models for type 2 diabetes mellitus (T2DM) have limited performance. We developed a deep learning (DL) based model using a cohort representative of the Korean population. Methods: This study was conducted on the basis of the National Health Insurance Service-Health Screening (NHIS-HEALS) cohort of Korea. Overall, 335,302 subjects without T2DM at baseline were included. We developed the model based on 80% of the subjects, and verified the power in the remainder. Predictive models for T2DM were constructed using the recurrent neural network long short-term memory (RNN-LSTM) network and the Cox longitudinal summary model. The performance of both models over a 10-year period was compared using a time dependent area under the curve. Results: During a mean follow-up of 10.4±1.7 years, the mean frequency of periodic health check-ups was 2.9±1.0 per subject. During the observation period, T2DM was newly observed in 8.7% of the subjects. The annual performance of the model created using the RNN-LSTM network was superior to that of the Cox model, and the risk factors for T2DM, derived using the two models were similar; however, certain results differed. Conclusion The DL-based T2DM prediction model, constructed using a cohort representative of the population, performs better than the conventional model. After pilot tests, this model will be provided to all Korean national health screening recipients in the future.

Collagenous fibroma (CF) is a rare benign tumor that occurs at various anatomical sites including the head and neck. CFs are often omitted from differential diagnosis before surgery. We describe a case of CF in a 54-year-old male who presented with a growing neck mass of 1-year duration at the site of previous right hemithyroidectomy for papillary thyroid carcinoma (PTC). Although radiologic findings demonstrated a benign tumor, surgical excision was carried out per patient’s preference and to rule out recurrent thyroid cancer. The mass was severely adherent to the surrounding muscles, but was resected completely without any injury to the adjacent structures. Histological studies revealed CF. The postoperative course was uneventful without vocal fold paralysis. CFs can be a diagnostic challenge in preoperative evaluation. Conservative excision was sufficient in most cases without recurrence. Clinicians should be aware of CFs in diagnosis, especially in postoperative site.

Background: Previously developed prediction models for type 2 diabetes mellitus (T2DM) have limited performance. We developed a deep learning (DL) based model using a cohort representative of the Korean population. Methods: This study was conducted on the basis of the National Health Insurance Service-Health Screening (NHIS-HEALS) cohort of Korea. Overall, 335,302 subjects without T2DM at baseline were included. We developed the model based on 80% of the subjects, and verified the power in the remainder. Predictive models for T2DM were constructed using the recurrent neural network long short-term memory (RNN-LSTM) network and the Cox longitudinal summary model. The performance of both models over a 10-year period was compared using a time dependent area under the curve. Results: During a mean follow-up of 10.4±1.7 years, the mean frequency of periodic health check-ups was 2.9±1.0 per subject. During the observation period, T2DM was newly observed in 8.7% of the subjects. The annual performance of the model created using the RNN-LSTM network was superior to that of the Cox model, and the risk factors for T2DM, derived using the two models were similar; however, certain results differed. Conclusion The DL-based T2DM prediction model, constructed using a cohort representative of the population, performs better than the conventional model. After pilot tests, this model will be provided to all Korean national health screening recipients in the future.

Molecular biomarker testing is the standard of care for non–small cell lung cancer (NSCLC) patients. In 2017, the Korean Cardiopulmonary Pathology Study Group and the Korean Molecular Pathology Study Group co-published a molecular testing guideline which contained almost all known genetic changes that aid in treatment decisions or predict prognosis in patients with NSCLC. Since then there have been significant changes in targeted therapies as well as molecular testing including newly approved targeted drugs and liquid biopsy. In order to reflect these changes, the Korean Cardiopulmonary Pathology Study Group developed a consensus statement on molecular biomarker testing. This consensus statement was crafted to provide guidance on what genes should be tested, as well as methodology, samples, patient selection, reporting and quality control.

With advances in target therapy, molecular analysis of tumors is routinely required for treatment decisions in patients with advanced non-small cell lung cancer (NSCLC). Liquid biopsy refers to the sampling and analysis of circulating cell-free tumor DNA (ctDNA) in various body fluids, primarily blood. Because the technique is minimally invasive, liquid biopsies are the future in cancer management. Epidermal growth factor receptor (EGFR) ctDNA tests have been performed in routine clinical practice in advanced NSCLC patients to guide tyrosine kinase inhibitor treatment. In the near future, liquid biopsy will be a crucial prognostic, predictive, and diagnostic method in NSCLC. Here we present the current status and future perspectives of liquid biopsy in NSCLC.

BACKGROUND: Assessment of programmed cell death-ligand 1 (PD-L1) immunohistochemical staining is used for treatment decisions in non-small cell lung cancer (NSCLC) regarding use of PD-L1/programmed cell death protein 1 (PD-1) immunotherapy. The reliability of the PD-L1 22C3 pharmDx assay is critical in guiding clinical practice. The Cardiopulmonary Pathology Study Group of the Korean Society of Pathologists investigated the interobserver reproducibility of PD-L1 staining with 22C3 pharmDx in NSCLC samples.METHODS: Twenty-seven pathologists individually assessed the tumor proportion score (TPS) for 107 NSCLC samples. Each case was divided into three levels based on TPS: <1%, 1%–49%, and ≥50%.RESULTS: The intraclass correlation coefficient for TPS was 0.902±0.058. Weighted κ coefficient for 3-step assessment was 0.748±0.093. The κ coefficients for 1% and 50% cut-offs were 0.633 and 0.834, respectively. There was a significant association between interobserver reproducibility and experience (formal PD-L1 training, more experience for PD-L1 assessment, and longer practice duration on surgical pathology), histologic subtype, and specimen type.CONCLUSIONS: Our results indicate that PD-L1 immunohistochemical staining provides a reproducible basis for decisions on anti–PD-1 therapy in NSCLC.
Carcinoma, Non-Small-Cell Lung ; Cell Death ; Immunohistochemistry ; Immunotherapy ; Observer Variation ; Pathology