Objective: Traumatic occult pneumothorax is defined as a pneumothorax that cannot be identified with a simple chest X-ray and can be detected only by chest computed tomography (CT). The purpose of this study was to retrospectively recognize the difference between thoracostomy and conservative treatment of traumatic occult pneumothorax. Methods: Among the thoracic trauma inpatients who visited a single emergency room (ER) from January 2021 to May 2022, adult patients aged over 18 years, diagnosed with traumatic pneumothorax who survived their ER stay and with abnormalities were included as the final study subjects and their histories were compared. Results: Of the total of 269 thoracic trauma patients, 110 were diagnosed with traumatic pneumothorax, of which 30 were traumatic occult pneumothorax patients. Multiple logistic regression analyses performed in the traumatic occult pneumothorax patient group showed that as the pneumothorax size increased, the probability of finding an occult pneumothorax decreased (odds ratio [OR]=0.93; 95% confidence interval [CI], 0.89-0.98). In very severe cases of rib fractures (OR=0.65; 95% CI, 0.43-0.98), the probability of detecting occult pneumothorax was reduced. Among the patients with traumatic occult pneumothorax, 15 patients underwent thoracostomy. Cases of hemothorax (70%; P=0.05), surgery (26.67%; P<0.01), and higher injury severity scores (12.87±7.69; P=0.02) were more common in the thoracostomy group. Conclusion Usually traumatic occult pneumothorax is treated conservatively with regular follow-up, but thoracostomy is necessary when it is accompanied by hemothorax and for patients requiring surgery and having a higher injury severity score.

Objective: Traumatic occult pneumothorax is defined as a pneumothorax that cannot be identified with a simple chest X-ray and can be detected only by chest computed tomography (CT). The purpose of this study was to retrospectively recognize the difference between thoracostomy and conservative treatment of traumatic occult pneumothorax. Methods: Among the thoracic trauma inpatients who visited a single emergency room (ER) from January 2021 to May 2022, adult patients aged over 18 years, diagnosed with traumatic pneumothorax who survived their ER stay and with abnormalities were included as the final study subjects and their histories were compared. Results: Of the total of 269 thoracic trauma patients, 110 were diagnosed with traumatic pneumothorax, of which 30 were traumatic occult pneumothorax patients. Multiple logistic regression analyses performed in the traumatic occult pneumothorax patient group showed that as the pneumothorax size increased, the probability of finding an occult pneumothorax decreased (odds ratio [OR]=0.93; 95% confidence interval [CI], 0.89-0.98). In very severe cases of rib fractures (OR=0.65; 95% CI, 0.43-0.98), the probability of detecting occult pneumothorax was reduced. Among the patients with traumatic occult pneumothorax, 15 patients underwent thoracostomy. Cases of hemothorax (70%; P=0.05), surgery (26.67%; P<0.01), and higher injury severity scores (12.87±7.69; P=0.02) were more common in the thoracostomy group. Conclusion Usually traumatic occult pneumothorax is treated conservatively with regular follow-up, but thoracostomy is necessary when it is accompanied by hemothorax and for patients requiring surgery and having a higher injury severity score.

Objective: Traumatic occult pneumothorax is defined as a pneumothorax that cannot be identified with a simple chest X-ray and can be detected only by chest computed tomography (CT). The purpose of this study was to retrospectively recognize the difference between thoracostomy and conservative treatment of traumatic occult pneumothorax. Methods: Among the thoracic trauma inpatients who visited a single emergency room (ER) from January 2021 to May 2022, adult patients aged over 18 years, diagnosed with traumatic pneumothorax who survived their ER stay and with abnormalities were included as the final study subjects and their histories were compared. Results: Of the total of 269 thoracic trauma patients, 110 were diagnosed with traumatic pneumothorax, of which 30 were traumatic occult pneumothorax patients. Multiple logistic regression analyses performed in the traumatic occult pneumothorax patient group showed that as the pneumothorax size increased, the probability of finding an occult pneumothorax decreased (odds ratio [OR]=0.93; 95% confidence interval [CI], 0.89-0.98). In very severe cases of rib fractures (OR=0.65; 95% CI, 0.43-0.98), the probability of detecting occult pneumothorax was reduced. Among the patients with traumatic occult pneumothorax, 15 patients underwent thoracostomy. Cases of hemothorax (70%; P=0.05), surgery (26.67%; P<0.01), and higher injury severity scores (12.87±7.69; P=0.02) were more common in the thoracostomy group. Conclusion Usually traumatic occult pneumothorax is treated conservatively with regular follow-up, but thoracostomy is necessary when it is accompanied by hemothorax and for patients requiring surgery and having a higher injury severity score.

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Purpose: Optimal treatment for stage IIIA/N2 non–small cell lung cancer (NSCLC) is controversial. We aimed to assess the efficacy and safety of adjuvant pembrolizumab for stage IIIA/N2 NSCLC completely resected after neoadjuvant concurrent chemoradiation therapy (CCRT). Materials and Methods: In this open-label, single-center, single-arm phase 2 trial, patients with stage IIIA/N2 NSCLC received adjuvant pembrolizumab for up to 2 years after complete resection following neoadjuvant CCRT. The primary endpoint was disease-free survival (DFS). Secondary endpoints included overall survival (OS) and safety. As an exploratory biomarker analysis, we evaluated the proliferative response of blood CD39+PD-1+CD8+ T cells using fold changes in the percentage of proliferating Ki-67+ cells from days 1 to 7 of cycle 1 (Ki-67D7/D1). Results: Between October 2017 and October 2018, 37 patients were enrolled. Twelve (32%) and three (8%) patients harbored EGFR and ALK alterations, respectively. Of 34 patients with programmed cell death ligand 1 assessment, 21 (62%), nine (26%), and four (12%) had a tumor proportion score of < 1%, 1%-50%, and ≥ 50%, respectively. The median follow-up was 71 months. The median DFS was 22.4 months in the overall population, with a 5-year DFS rate of 29%. The OS rate was 86% at 2 years and 76% at 5 years. Patients with tumor recurrence within 6 months had a significantly lower Ki-67D7/D1 among CD39+PD-1+CD8+ T cells than those without (p=0.036). No new safety signals were identified. Conclusion Adjuvant pembrolizumab may offer durable disease control in a subset of stage IIIA/N2 NSCLC patients after neoadjuvant CCRT and surgery.

Background: Recent reports have suggested that pneumonitis is a rare complication following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).However, its clinical features and outcomes are not well known. The aim of this study was to identify the clinical characteristics and outcomes of patients with vaccine-associated pneumonitis following vaccination against SARS-CoV-2. Methods: In this nationwide multicenter survey study, questionnaires were distributed to pulmonary physicians in referral hospitals. They were asked to report cases of development or exacerbation of interstitial lung disease (ILD) associated with the coronavirus disease 2019 vaccine. Vaccine-associated pneumonitis was defined as new pulmonary infiltrates documented on chest computed tomography within 4 weeks of vaccination and exclusion of other possible etiologies. Results: From the survey, 49 cases of vaccine-associated pneumonitis were identified between February 27 and October 30, 2021. After multidisciplinary discussion, 46 cases were analyzed. The median age was 66 years and 28 (61%) were male. The median interval between vaccination and respiratory symptoms was 5 days. There were 20 (43%), 17 (37%), and nine (19%) patients with newly identified pneumonitis, exacerbation of pre-diagnosed ILD, and undetermined pre-existing ILD, respectively. The administered vaccines were BNT162b2 and ChAdOx1 nCov-19/AZD1222 each in 21 patients followed by mRNA-1273 in three, and Ad26.COV2.S in one patient. Except for five patients with mild disease, 41 (89%) patients were treated with corticosteroid. Significant improvement was observed in 26 (57%) patients including four patients who did not receive treatment. However, ILD aggravated in 9 (20%) patients despite treatment. Mortality was observed in eight (17%) patients. Conclusion These results suggest pneumonitis as a potentially significant safety concern for vaccines against SARS-CoV-2. Clinical awareness and patient education are necessary for early recognition and prompt management. Additional research is warranted to identify the epidemiology and characterize the pathophysiology of vaccine-associated pneumonitis.

Objective: Early identification of COVID-19 in patients is important to prevent significant worsening of the disease. This study was undertaken to verify whether MEWS (Modified Early Warning Score), NEWS(National Early Warning Score), ROX index, and CURB-65, which are early diagnostic tools for severe respiratory diseases, could be applied to patients visiting the emergency room for COVID-19. Methods: This retrospective observational study included patients who visited an emergency medical center from September 1 to October 31, 2020, and from January 1 to February 28, 2021. Based on the vital signs and blood tests during the emergency room visit, severity evaluation tools and early diagnostic tools for severe cases were used and compared according to their area under the curve (AUC) values. The primary outcome was in-hospital mortality, while the secondary outcomes were intensive care unit admission rate and the need for mechanical ventilation based on these four tools (MEWS, NEWS, ROX index, and CURB-65). Results: A total of 667 patients were analyzed. No significant difference was determined between the non-survivor group and survivor group in the MEWS values (P=0.13), but statistically significant differences were observed for NEWS (5 vs. 1, P<0.05), CURB-65 (2 vs. 1, P<0.05), and ROX index (16.61 vs. 23.1, P<0.01). The AUC value of NEWS for death prediction indicated a good predictive power at 0.80, while that of MEWS showed a low predictive power at 0.57, which was statistically significant. Moreover, the AUC values of CURB-65 and ROX index did not differ significantly from values obtained for NEWS. Conclusion As early diagnostic tools for predicting death in COVID-19 patients, NEWS, ROX index, and CURB-65 showed excellent discrimination ability, whereas MEWS showed statistically and significantly lower discrimination ability.

Clear cell acanthoma is a rare benign tumor, which usually presents as a solitary erythematous to brown colored papule or nodule, with a predilection for the lower leg of t hemiddle-aged and older individuals. An 11-year-old male presented with a 1-month history of bilateral brownish colored and exudative plaques on the both areolae.Histopathologic examination showed psoriasiform proliferation of pale keratinocytes and neutrophil exocytosis. Therefore, the patient was diagnosed with clear cell acanthoma. Typically, clear cell acanthoma occurs as a unilateral lesion on the leg in an adult. However, our case shows a bilateral lesion as well as the uncommon age and site.To our knowledge, this case of bilateral clear cell acanthoma has been rarely reported in Korea. Herein, we report a case of clear cell acanthoma that occurred on both areolae in a child.

Background/Aims: There have been little research on the cancer risks of patients with Peutz-Jeghers syndrome (PJS) in Korea. We aimed to investigate the clinical features of PJS patients and their cancer incidence rate. Methods: Patients with PJS from nine medical centers were enrolled. In those patients diagnosed with cancer, data obtained included the date of cancer diagnosis, the tumor location, and the cancer stage. The cumulative risks of gastrointestinal cancers and extra-gastrointestinal cancers were calculated using the Kaplan-Meier method. Results: A total of 96 PJS patients were included. The median age at diagnosis of PJS was 23.4 years. Cancer developed in 21 of the 96 patients (21.9%). The age of PJS diagnosis was widely distributed (0.9 to 72.4 years). The most common cancers were gastrointestinal cancer (n = 12) followed by breast cancer (n = 6). The cumulative lifetime cancer risk was calculated to be 62.1% at age 60. The cumulative lifetime gastrointestinal cancer risk was 47.1% at age 70. The cumulative lifetime extra- gastrointestinal cancer risk was 40.3% at age 60. Conclusions PJS onset may occur at any age and the risks of gastrointestinal and extra-gastrointestinal cancer are high. Thorough surveillance of PJS patients for malignancies is vital.

Purpose: We aimed to compare the oncological outcomes and toxicities of definitive proton beam therapy (PBT) and photon beam therapy in patients with limited-stage small cell lung cancer (LS-SCLC). Materials and Methods: We retrospectively reviewed 262 patients with newly diagnosed LS-SCLC who underwent definitive PBT (n = 20; proton group) or photon beam therapy (n = 242; photon group) with concurrent chemotherapy between January 2016 and February 2021 and compared overall survival (OS), progression-free survival (PFS), dose-volume parameters, and toxicities between the groups. Results: The median follow-up duration was 24.5 months (range, 3.7 to 78.7). Baseline lung function was significantly worse and clinical target volume (CTV) was larger in the proton group (CTV: 296.6 vs. 215.3 mL; p = 0.080). The mean lung V10 was 37.7% ± 16.8% and 51.6% ± 24.5% in the proton and photon groups, respectively (p = 0.002). Two-year OS and PFS rates were 57.2% and 35.7% in the proton group and 65.3% and 40.8% in the photon group, respectively (p = 0.542 and 0.748, respectively). Grade ≥2 radiation pneumonitis and esophagitis occurred in 5 (25.0%) and 7 (35.0%) PBT-treated patients and 66 (27.3%) and 40 (16.5%) photon beam therapy-treated patients, respectively (p = 0.826 and 0.062, respectively). Conclusion Although the proton group had poorer lung function and a larger CTV than that in the photon group, both groups exhibited comparable treatment outcomes and radiation-related toxicities in LS-SCLC. PBT may be a valuable therapeutic modality in patients with poor pulmonary function or extensive disease burden owing to its lung-sparing ability.