Prospective Observation Study for Primary Spontaneous Pneumothorax: Incidence of and Risk Factors for Postoperative Neogenesis of Bullae.

PURPOSE: Details of the neogenesis of bullae (NOB), which causes recurrent primary spontaneous pneumothorax (PSP) following bullectomy, have not been reported and risk factors for NOB remain unclear. We aimed to clarify the details of NOB. METHODS: We conducted a prospective study using three computed tomography (CT) examinations performed 6, 12, and 24 months after bullectomy to identify the incidence of and risk factors for NOB. We enrolled 50 patients who underwent bullectomy for PSP. RESULTS: After excluding 11 patients who canceled the postoperative CT examination at 6 months after bullectomy, only 39 patients were analyzed. The incidence of NOB at 6, 12, and 24 months after bullectomy was 38.5%, 55.2%, and 71.2%, respectively. The rate of NOB in the operated lung was almost 2 times higher than that in the contralateral nonoperative lung. Male sex, multiple bullae on preoperative CT, long stapling line (≥7 cm), deep stapling depth (≥1.5 cm), and heavier resected sample (≥5 g) were suggested to be risk factors for NOB. CONCLUSIONS: We recognized a high incidence of postoperative NOB in PSP patients. Bullectomy itself seems to promote NOB. Postoperative NOB occurs frequently, especially in patients who require a large-volume lung resection with a long staple line.

[Resected Right Upper Lobe Lung Cancer with Displaced Bronchus and Anomalous Pulmonary Vein].

The patient is a 77-year-old man. He was referred to our hospital after a chest computed tomography (CT) scan revealed a 6.5 cm-sized mass in the right lung apex. Bronchoscopy revealed adenocarcinoma, clinical stageⅡB, and the patient was referred for surgery. Preoperative 3D-CT revealed the presence of a displaced bronchus, probably B1a, branching from the right main bronchus centrally from the upper lobe bronchus, and an abnormal vessel (V2) running dorsal to the upper lobe bronchus and the right main bronchus, and returning directly to the left atrium. Surgery was performed by resectioning the right upper lobe through a posterolateral incision, combined resection of the wall pleura, and lymph node dissection (ND2a-2). Because lung cancer surgery is sometimes accompanied by abnormal bronchial and pulmonary vascular branches, it is essential to thoroughly examine the patient before surgery for checking abnormal branches by bronchoscopy and 3D-CT.

Marginal calcification of thymoma: differences in the location of calcification indicate differences in the characteristics of thymomas.

Background: Thymic epithelial tumors (TETs) are the most common tumors located in the anterior mediastinum. Calcification is sometimes observed in thymomas, especially in thymomas, and has been reported to be an indicator of the invasive behavior of thymomas. However, whether or not all calcification indicates invasive behavior is unclear. The present study therefore analyzed the location, size, and patterns of thymoma calcification and the relationships between calcification and clinicopathological factors and prognosis. Methods: We conducted a retrospective study among 77 thymoma patients who underwent surgery between January 2012 and May 2022 and analyzed the relationship between the location of calcification and clinicopathological findings. The patients were categorized into three groups: those with inner calcification of the tumor (group I), those with marginal calcification (group M), and those without any calcification (group N). Results: Calcification was identified in 13 thymomas (16.9%) in group I (n=8) and group M (n=5). Group M included significantly more low-risk thymomas than the other groups (P=0.030). In low-risk thymomas, especially type AB thymoma, marginal calcification was observed more frequently than in other lesions. There were significant differences in age (P=0.024) and Masako-Koga stage (P=0.020) among the groups. In group I, younger patients and patients with advanced-stage disease were included. There were no significant differences in the rates of recurrence or the recurrence-free period among the groups. However, recurrence was not recognized in any members of group M. Conclusions: The location of calcification should be a point of focus in thymomas, and differences in the location of calcification indicate differences in the characteristics of thymomas.

Real-world evidence of safety and influence for lung cancer surgery under COVID-19 pandemic in Japan.

Background: The COVID-19 pandemic has affected the clinical practice of lung cancer surgery in Japan, but few studies have revealed the real situation of surgical practice for lung cancer in this country. This latest information will help us to decide the future direction of lung cancer surgery under pandemic circumstances. Methods: We collected data from patients with primary lung cancer who underwent thoracic surgery between 2018 and 2021. To investigate the impact of the COVID-19 pandemic on lung cancer surgery, we compared between 2018-2019 (prepandemic group) and 2020-2021 (pandemic group) in the respect of patient characteristics, pathological findings, and short-term outcome after lung cancer resection by Mann-Whitney and Fisher's exact tests. Moreover, the monthly number of surgeries for lung cancer in our institution during 2020-2021 was compared with the number of newly diagnosed COVID-19 patients in Japan by Spearman correlation analysis. Results: From 2018 through 2021, 936 patients with primary lung cancer underwent surgical intervention in our institute and were included in this study. The number of surgeries did not decrease in the pandemic group (n=443) compared with that in the prepandemic group (n=493). Tumor and invasive size in stage I which was measured by pathologist were significantly larger in the pandemic group than in the prepandemic group (tumor size: P=0.031, invasive size: P<0.001). In terms of postoperative short-term outcome, the median hospital stay was 6 days, 30-day mortality was 2, and morbidity was around 20% in both groups. Only one patient suffered from COVID-19 infection 5 months after right upper lobectomy. An increased ratio of newly diagnosed COVID-19 cases in Japan was negatively correlated with the number of surgeries for lung cancer in our institution in the next month (r=-0.393, P=0.007), although there was no correlation in the present or the month after next. Conclusions: Even during the COVID-19 pandemic period, lung cancer surgery could be performed safely and in a sustainable manner. However, pathological findings of lung cancer tended to be progressive in early-stage lung cancer.

The Epstein-Barr virus BRRF2 gene product is involved in viral progeny production.

The Epstein-Barr virus (EBV) predominantly establishes a latent infection in B lymphocytes, and occasionally switches from the latent state to the lytic cycle. In this report, we identified and examined the role of a lytic gene, BRRF2. We first prepared an antibody against BRRF2 and identified the gene product as a viral lytic protein expressed in B95-8 cells with late kinetics. Immunofluorescence revealed that BRRF2 localized in the cytoplasm of cells during the lytic phase. We also found that BRRF2 protein was phosphorylated in lytic cells, but the only viral protein kinase, BGLF4, was not involved in the phosphorylation. Knockout EBV and a repaired strain were then prepared, and we found that BRRF2 disruption did not affect viral gene expression and DNA replication, but decreased virus production. These results demonstrated that BRRF2 is involved in production of infectious progeny, although it is not essential for lytic replication.