Malignant Solitary Fibrous Tumor of the Mediastinum with Multiple Recurrences and a Rare Metastasis to the Thyroid Gland: A Case Report.

Solitary fibrous tumors (SFTs) are rare neoplasms arising from mesenchymal cells. Although most SFTs are benign, rare cases of metastasis have been reported at various sites. Complete surgical resection is the mainstay of treatment for both primary and recurrent or metastatic SFTs. Herein, we present a case of an SFT initially identified in the anterior mediastinum that later developed multiple metastases, even to the thyroid gland. The patient underwent repeated surgical resection and is currently being followed up in an outpatient setting.

Genetic Alterations and Risk Factors for Recurrence in Patients with Non-Small Cell Lung Cancer Who Underwent Complete Surgical Resection.

A definitive surgical resection is the preferred treatment for early-stage non-small cell lung cancer (NSCLC). Research on genetic alterations, including epidermal growth factor receptor (EGFR) mutations, in early-stage NSCLC remains insufficient. We investigated the prevalence of genetic alterations in early-stage NSCLC and the association between EGFR mutations and recurrence after a complete resection. Between January 2019 and December 2021, 659 patients with NSCLC who underwent curative surgical resections at a single regional cancer center in Korea were recruited. We retrospectively compared the clinical and pathological data between the recurrence and non-recurrence groups. Among the 659 enrolled cases, the median age was 65.86 years old and the most common histology was adenocarcinoma (74.5%), followed by squamous cell carcinoma (21.7%). The prevalence of EGFR mutations was 43% (194/451). Among them, L858R point mutations and exon 19 deletions were 52.3% and 42%, respectively. Anaplastic lymphoma kinase (ALK) rearrangement was found in 5.7% of patients (26/453) and ROS proto-oncogene 1 (ROS1) fusion was found in 1.6% (7/441). The recurrence rate for the entire population was 19.7%. In the multivariate analysis, the presence of EGFR mutations (hazard ratio (HR): 2.698; 95% CI: 1.458-4.993; p = 0.002), stage II (HR: 2.614; 95% CI: 1.29-5.295; p = 0.008) or III disease (HR: 9.537; 95% CI: 4.825-18.852; p < 0.001) (vs. stage I disease), and the presence of a pathologic solid type (HR: 2.598; 95% CI: 1.405-4.803; p = 0.002) were associated with recurrence. Among the recurrence group, 86.5% of the patients with EGFR mutations experienced distant metastases compared with only 66.7% of the wild type (p = 0.016), with no significant difference in median disease-free survival (52.21 months vs. not reached; p = 0.983). In conclusion, adjuvant or neoadjuvant targeted therapy could be considered more actively because EGFR mutations were identified as an independent risk factor for recurrence and were associated with systemic recurrence. Further studies on perioperative therapy for other genetic alterations are necessary.

Intracardiac Thymoma with Superior Vena Cava and Left Brachiocephalic Vein Extension: A Case Report.

Thymomas are common anterior mediastinal tumors with a relatively favorable prognosis compared to that of other types of thoracic malignancies. However, thymomas that invade surrounding structures, such as the heart or vena cava, have been infrequently reported, and intracardiac thymomas are exceedingly rare. Treatment of invasive thymoma is difficult because the high rate of incomplete resection results in a high rate of recurrence. Herein, we present a rare case of a thymoma that originated in the right atrium and extended into the superior vena cava and brachiocephalic vein.

Surgical Experience with Descending Necrotizing Mediastinitis: A Retrospective Analysis at a Single Center.

Background: We analyzed our experience with descending necrotizing mediastinitis (DNM) treatment and investigated the efficacy of video-assisted thoracoscopic surgery (VATS) for mediastinal drainage. Methods: This retrospective analysis included patients who underwent surgical drainage for DNM at our hospital from 2005 to 2020. We analyzed patients' baseline characteristics, surgical data, and perioperative outcomes and compared them according to the mediastinal drainage approach among patients with type II DNM. Results: Twenty-five patients (male-to-female ratio, 18:7) with a mean age of 54.0±12.9 years were enrolled in this study. The most common infection sources were pharyngeal infections (60%). Most patients had significantly increased white blood cell counts, elevated C-reactive protein levels, and decreased albumin levels on admission. The most common DNM type was type IIB (n=16, 64%), while 5 and 4 patients had types I and IIA, respectively. For mediastinal drainage, the transcervical approach was used in 15 patients and the transthoracic approach (VATS) in 10 patients. The mean length of hospital stay was 26.5±23.8 days, and the postoperative morbidity and in-hospital mortality rates were 24% and 12%, respectively. No statistically significant differences were found among patients with type II DNM between the transcervical and VATS groups. However, the VATS group showed shorter mean antibiotic therapy duration, drainage duration, and hospital stay length than the transcervical group. Conclusion: DNM manifested as severe infection requiring long-term inpatient treatment, with a mortality rate of 12%. Thus, active treatment with a multidisciplinary approach is crucial, and mediastinal drainage using VATS is considered relatively safe and effective.

Silicone Granuloma Mimicking a Lymphatic Metastasis in a Lung Cancer Patient: A Case Report.

Silicone granulomas are rare, benign lesions that may occur after breast augmentation. Occasionally, a careful differential diagnosis is necessary because lymphadenopathy or malignancy is suspected based on an imaging study. A 56-year-old woman who visited the hospital due to a lung nodule in the left upper lobe (LUL) underwent a staging work-up with the suspicion of lung cancer. Positron emission tomography/computed tomography and chest computed tomography revealed the LUL nodule and a lesion in the left internal mammary chain (IMC), suggesting lymphadenopathy. Diagnostic wedge resection was performed, followed by curative surgery. The final biopsy result confirmed that the LUL nodule was pathologic stage IB adenocarcinoma; unexpectedly, the lesion in the left IMC was a silicone granuloma.

Minimally Invasive Surgical Treatment of Hepatic Hydrothorax Complicated by Empyema: A Case Report.

Hepatic hydrothorax complicated by empyema is difficult to manage. A 53-year-old man with liver cirrhosis was admitted for refractory right pleural effusion. He had a pleural catheter inserted 2 months prior. Pleural fluid appeared as exudate, and bacteria were identified in the pleural fluid culture. After confirming full ipsilateral lung expansion, minimally invasive surgery was performed. A diaphragmatic defect found by creating a pneumoperitoneum was closed, followed by talc pleurodesis. Postoperatively, overnight positive-pressure ventilation and 5-day peritoneal drainage were performed; chest tube drainage dramatically reduced over this time. At the 10-month follow-up, no recurrence of pleural effusion or signs of infection were observed.

Precise characterization of a solitary pulmonary nodule using tumor shadow disappearance rate-corrected F-18 FDG PET and enhanced CT.

ABSTRACT: We aimed to characterize solitary pulmonary nodule (SPN) using imaging parameters for F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) or enhanced CT corrected by tumor shadow disappearance rate (TDR) to reflect the tissue density.We enrolled 51 patients with an SPN who underwent PET/CT and chest CT with enhancement. The FDG uptake of SPN was evaluated using maximum standardized uptake value (SUVmax) on PET/CT. The mean Hounsfield unit (HU) for each SPN was evaluated over the region of interest on nonenhanced and enhanced CT images. The change in mean HU (HUpeak-pre) was quantified by subtracting the mean HU of the preenhanced CT from that of the post-enhanced CT. TDR was defined as the ratio of the tumor area, which disappears at a mediastinal window, to the tumor area of the lung window. We investigated which parameters (SUVmax or HUpeak-pre) could contribute to the characterization of SPN classified by TDR value and whether diagnostic performance could be improved using TDR-corrected imaging parameters.For SPN with higher tissue density (TDR <42%, n = 22), high value of SUVmax (≥3.1) was a significant factor to predict malignancy (P = .006). High value of HUpeak-pre (≥38) was a significant factor to characterize SPN (P = .002) with lower tissue density (TDR ≥42%, n = 29). The combined approach using TDR-corrected parameters had better predictive performance to characterize SPN than SUVmax only (P = .031).Applying imaging parameters such as SUVmax or HUpeak-pre in consideration of tissue density calculated with TDR could contribute to accurate characterization of SPN.

Successful Surgical Management of a Tracheo-Innominate Artery Fistula in a Patient with Duchenne Muscular Dystrophy: A Case Report.

Tracheo-innominate artery fistula (TIF) is a rare, life-threatening complication of tracheostomy that makes it difficult to secure the airway due to massive bleeding, constituting a medical emergency. Therefore, most successful surgical treatments include innominate artery debridement and tracheal fistula repair. Herein, we report a case of successful surgical treatment of a TIF while maintaining cerebral blood flow through an artificial vascular graft.

Thoracoscopic pulmonary metastasectomy in metastatic colorectal cancer: Surgical outcomes and prognostic factors.

BACKGROUND: This study aimed to confirm the effectiveness of thoracoscopic metastasectomy for colorectal cancer (CRC) and determine its prognostic factors. METHODS: Of the 181 patients who underwent video-assisted thoracoscopic surgery (VATS) for pulmonary metastases from CRC between 2011 and 2017, 173 were retrospectively reviewed. Surgical outcomes, long-term survival, and the factors affecting the prognosis were analyzed. RESULTS: The patients in the study were predominantly male (n = 104, 60.1%), and the median age was 65 years (range, 25-83 years). The median follow-up time was 46 months (range, 0-114 months). The surgical procedures were 156 wedge resections, five segmentectomies, and 12 lobectomies. Conversion to thoracotomy was required in nine patients. The postoperative complication rate was 2.9%, and the in-hospital mortality rate was 1.2%. The overall 1-, 3-, and 5-year survival rates were 94.8%, 70.6%, and 51.8%, respectively. Univariate analysis showed that the prognostic factors for survival were age (p = 0.027), pathological stage of CRC (p = 0.019), prior extrathoracic metastasis (p = 0.005), preoperative carcinoembryonic antigen level (p = 0.020), number of pulmonary metastases (p = 0.011), and disease-free interval (p = 0.026). In the multivariate analysis, two factors were related to prognosis: age (hazard ratio [HR], 1.881; 95% confidence interval [CI]; 1.189-2.976; p = 0.007) and prior extrathoracic metastasis (HR, 2.170; 95% CI; 1.269-3.711; p = 0.005). CONCLUSIONS: VATS for pulmonary metastasectomy for CRC can be performed relatively safely, and our results regarding long-term survival are comparable with those of other studies. In this study, older age (≥70 years) and prior extrathoracic metastasis were independent prognostic factors of poor prognosis.

Glutathione Peroxidase 3 as a Biomarker of Recurrence after Lung Cancer Surgery.

We aimed to examine the usefulness of serum glutathione peroxidase 3 (GPx3) as a biomarker of lung cancer recurrence after complete resection. We prospectively collected serial serum samples at the baseline, as well as 3, 6 and 12 months after surgery from complete resection cases in 2013. GPx3 levels were measured by enzyme-linked immunosorbent assay. Statistical tests including t-tests and Cox proportional hazard regression analyses were performed. Totally, 135 patients were enrolled, and 39 (28.9%) showed relapse during the median follow-up period (63.60 months; range, 0.167-81.867). The mean GPx3 change was significantly higher in the recurrence group at 6 months (0.32 ± 0.38 vs. 0.15 ± 0.29, p = 0.016) and 12 months (0.40 ± 0.37 vs. 0.13 ± 0.28, p = 0.001). The high GPx3 change group showed significantly higher 60-months recurrence rates than the low group (48.1% vs. 25.2% at 3 months, p = 0.005; 54.5% vs. 28.9% at 6 months, p = 0.018; 38.3% vs. 18.3% at 12 months, p = 0.035). High GPx3 change at 3 months were independent risk factors of recurrence (hazard ratio (HR) 3.318, 95% confidence interval (CI), 1.582-6.960, p = 0.002) and survival (HR 3.150, 95% CI, 1.301-7.628, p = 0.011). Therefore, serum GPx3 changes after surgery may be useful predictive biomarkers for recurrence in lung cancer. Larger-scale validation studies are warranted to confirm these findings.

Artificial intelligence and lung cancer treatment decision: agreement with recommendation of multidisciplinary tumor board.

BACKGROUND: IBM Watson for Oncology (WFO) is a cognitive computing system helping physicians quickly identify key information in a patient's medical record, surface relevant evidence, and explore treatment options. This study assessed the possibility of using WFO for clinical treatment in lung cancer patients. METHODS: We evaluated the level of agreement between WFO and multidisciplinary team (MDT) for lung cancer. From January to December 2018, newly diagnosed lung cancer cases in Chonnam National University Hwasun Hospital were retrospectively examined using WFO version 18.4 according to four treatment categories (surgery, radiotherapy, chemoradiotherapy, and palliative care). Treatment recommendations were considered concordant if the MDT recommendations were designated 'recommended' by WFO. Concordance between MDT and WFO was analyzed by Cohen's kappa value. RESULTS: In total, 405 (male 340, female 65) cases with different histology (adenocarcinoma 157, squamous cell carcinoma 132, small cell carcinoma 94, others 22 cases) were enrolled. Concordance between MDT and WFO occurred in 92.4% (k=0.881, P<0.001) of all cases, and concordance differed according to clinical stages. The strength of agreement was very good in stage IV non-small cell lung carcinoma (NSCLC) (100%, k=1.000) and extensive disease small cell lung carcinoma (SCLC) (100%, k=1.000). In stage I NSCLC, the agreement strength was good (92.4%, k=0.855). The concordance was moderate in stage III NSCLC (80.8%, k=0.622) and relatively low in stage II NSCLC (83.3%, k=0.556) and limited disease SCLC (84.6%, k=0.435). There were discordant cases in surgery (7/57, 12.3%), radiotherapy (2/12, 16.7%), and chemoradiotherapy (15/129, 11.6%), but no discordance in metastatic disease patients. CONCLUSIONS: Treatment recommendations made by WFO and MDT were highly concordant for lung cancer cases especially in metastatic stage. However, WFO was just an assisting tool in stage I-III NSCLC and limited disease SCLC; so, patient-doctor relationship and shared decision making may be more important in this stage.

Inflammatory myofibroblastic tumor arising from the ascending aorta mimicking a thymoma.

An inflammatory myofibroblastic tumor originating from the aorta is extremely rare. Here, we report a case involving a 41-year-old female patient with an aortic inflammatory myofibroblastic tumor. Although preoperative imaging showed a mediastinal mass indicative of invasive thymoma, surgical findings revealed that this mass originated from the aorta. The patient underwent partial resection of the aorta, including the mass with patch angioplasty. Based on the postoperative histological findings, the patient was diagnosed with an aortic inflammatory myofibroblastic tumor and is currently under outpatient follow-up.

Laparoscopic repair of hiatal hernia.

BACKGROUND: Laparoscopic hiatal hernia repair is a complex surgery typically performed by general abdominal surgeons because it typically involves an abdominal approach. Here, we report our experiences on laparoscopic repair of hiatal hernia as thoracic surgeons. METHODS: Based on our experience of minimally invasive esophageal surgery (MIES) for esophageal cancer, we began performing laparoscopic repair of hiatal hernia in 2009. We analyzed the surgery-related data and postoperative outcomes of 18 consecutive patients we operated on from 2009 to 2017. RESULTS: There were 1 male and 17 female patients with a median age of 73 years (range, 37-81 years). Ten of 14 symptomatic patients experienced reflux symptoms, such as heartburn. Four patients had a history of prior abdominal surgery. Hiatal hernia types I, II, III, and IV were observed in 3, 9, 5, and 1 patients, respectively. Two (11.1%) laparoscopic procedures required conversion. Modified Collis gastroplasty was used as an esophageal lengthening procedure in 5 patients (27.8%). Mean operation time was 213.8±70.1 minutes and mean hospital stay was 6.2±1.5 days. There were no postoperative complications. At the last follow-up, 15 patients (83.3%) were asymptomatic; however, 3 (16.7%) complained of reflux or dysphagia. Recurrent hiatal hernia was detected on an esophagogram in only 1 patient at 3.5 years after laparoscopic surgery. CONCLUSIONS: Laparoscopic repair of hiatal hernia is a feasible technique with a satisfactory surgical outcome. Importantly, it can be performed by thoracic surgeons who are experienced in the laparoscopic approach.

Synchronous primary glomus tumor in a patient with adenocarcinoma of the ipsilateral lung.

Glomus tumors are rare mesenchymal neoplasms arising from the glomus bodies in the deep dermis of the extremities or derive from the modified smooth muscle cells of the normal glomus body. Primary pulmonary glomus tumors are particularly rare and infrequently reported. We report a case of a primary glomus tumor occurring in the lung with adenocarcinoma in the ipsilateral lung as synchronous lung cancers in a 69-year-old man. He underwent lobectomy for adenocarcinoma and wedge resection for the glomus tumor with mediastinal lymph node dissection and was doing well without recurrence or metastasis at the last follow-up.

Surgery for hemoptysis in patients with benign lung disease.

BACKGROUND: Hemoptysis can be a life-threatening condition that requires urgent treatment. Surgery still plays an important role in managing this critical situation, although previous reports have reported high postoperative morbidity and mortality rates. We report our experience with surgical resection for hemoptysis caused by benign lung diseases. METHODS: We reviewed the retrospectively collected data from 94 patients undergoing pulmonary resection for various benign lung diseases with hemoptysis at a single institution from 2010 to 2016. Baseline characteristics, surgical factors, and postoperative outcomes (morbidity and mortality rates) were analyzed. RESULTS: The ratio of male to female patients was 1:1, and the mean age was 58.2±11.1 (range, 29-79) years. The etiology of hemoptysis included aspergilloma in 58 patients (61.7%), bronchiectasis in 10, tuberculosis in 7, necrotizing bronchiolitis in 6, and other inflammatory disease in 13. A total of 21 patients (22.3%) underwent emergency operation, and 73 (77.7%) had an elective operation. Pulmonary resection was performed by thoracotomy (n=53, 56.4%) and video-assisted thoracoscopic surgery (VATS) (n=41, 43.6%). Sublobar resection (n=50, 53.2%, segmentectomy in 19 and wedge resection in 31) was performed more often than lobectomy (n=35, 37.2%). Pneumonectomy was performed in 7 patients, and bilobectomy was performed in 2. Postoperative morbidity occurred in 23 patients (24.5%), with prolonged air leak being the most frequent complication (n=14, 14.9%). The in-hospital mortality rate was 3.2% (n=3). Complications were less frequent in patients undergoing an elective operation, VATS, and sublobar resection. Multivariate analysis showed that patients treated with VATS had a decreased risk of postoperative complications (odds ratio, 12.8; 95% confidence interval, 1.29-127.9; P=0.03). CONCLUSIONS: Surgical resection for hemoptysis in patients with benign lung diseases is the mainstay of effective treatment with acceptable morbidity and mortality rates. If applicable, we recommend elective (planned) sublobar resection using VATS in order to improve postoperative outcomes.

Comparison of perioperative outcomes following hybrid minimally invasive versus open Ivor Lewis esophagectomy for esophageal cancer.

BACKGROUND: The outcomes of various minimally invasive esophagectomy (MIE) procedures for esophageal cancer have been reported; however, those of the hybrid approach are lacking. This study aimed to assess the impacts of hybrid minimally invasive Ivor Lewis esophagectomy (HIL, laparoscopy and right thoracotomy) for esophageal cancer on perioperative outcomes compared with the open approach. METHODS: This was a retrospective study of 153 patients who underwent Ivor Lewis esophagectomy for squamous cell carcinoma between January 2008 and December 2016. Patients who received neoadjuvant treatment prior to surgery (n=22) and underwent complete minimally invasive procedures (n=16) were excluded. Clinical characteristics and perioperative outcomes of patients who underwent HIL (n=53) were compared with findings in patients who underwent open Ivor Lewis esophagectomy (OIL, n=62). RESULTS: There were 112 men (97.4%) and 3 women (2.6%) with a median age of 66 years (range, 45-83 years). The HIL and OIL groups were comparable with respect to age, sex, preoperative pulmonary function, location of the tumor, and preoperative laboratory findings. There was no significant difference between the two groups regarding surgical data, except for pyloric management. Postoperative complications occurred in 17 (32.1%) and 23 (37.1%) patients in the HIL and OIL groups, respectively (P=0.573); in-hospital mortality rates were 3.8% and 8.1%, respectively (P=0.337). HIL group patients had higher albumin (3.3 vs. 2.9 g/dL; P<0.001) and lower C-reactive protein (6.4 vs. 8.1 mg/L; P<0.001) postoperatively. The length of hospital stay was shorter in the HIL group (13.5 vs. 19.2 days; P=0.002). CONCLUSIONS: Compared with the conventional open approach, HIL for esophageal cancer showed better postoperative nutritional and inflammatory status, resulting in shorter hospital stays. However, further studies are required to evaluate the long-term oncologic outcomes of this hybrid approach.

Doege-potter syndrome: a report of a histologically benign but clinically malignant case.

BACKGROUND: Solitary fibrous tumors of the pleura (SFTPs) are relatively rare tumors that originate from mesenchymal cells of submesothelial tissue of the pleura. Most patients with SFTPs are asymptomatic; however, pleuritic chest pain, cough, and dyspnea can develop. If hypoglycemia is associated with a solitary fibrous tumor, it is referred to as the Doege-Potter syndrome. CASE PRESENTATION: A 70-year-old man had visited our hospital with a chief complaint of dyspnea, and he was diagnosed as having a solitary fibrous tumor. A few years later, he developed hypoglycemia, and he underwent excision of the mass. CONCLUSION: Occasionally, SFTPs induce several paraneoplastic events, such as hypertrophic osteoarthropathy. We described here a patient with an SFTP with Doege-Potter syndrome who was successfully treated with complete resection. Although lesions can be histologically benign, they can clinically present with malignant features.

Primary pulmonary myxoid sarcoma located in interlobar fissure without parenchymal invasion.

Primary pulmonary myxoid sarcoma (PPMS), classified as low to intermediate grade malignant myxoid endobronchial tumor, is rarely reported. Most reported cases occurred in lung parenchyme with an endobronchial component. Herein, we report a case of PPMS in a 29-year-old woman that developed in a major fissure of the left lung without parenchymal invasion. Histopathologically, the diagnosis was compatible to PPMS with EWSR1-CREB1 translocation.

Nosocomial Infection in Adult Patients Undergoing Veno-Arterial Extracorporeal Membrane Oxygenation.

Data on the frequency of nosocomial infections during extracorporeal membrane oxygenation (ECMO) in adult populations remain scarce. We investigated the risk factors for nosocomial infections in adult patients undergoing venoarterial ECMO (VA-ECMO) support. From January 2011 to December 2015, a total of 259 patients underwent ECMO. Of these, patients aged 17 years or less and patients undergoing ECMO for less than 48 hours were excluded. Of these, 61 patients diagnosed with cardiogenic shock were evaluated. Mean patient age was 60.6 ± 14.3 years and 21 (34.4%) patients were female. The mean preoperative Sequential Organ Failure Assessment (SOFA) score was 8.6 ± 2.2. The mean duration of ECMO support was 6.8 ± 7.4 days. The rates of successful ECMO weaning and survival to discharge were 44.3% and 31.1%, respectively. There were 18 nosocomial infections in 14 (23.0%) patients. These included respiratory tract infections in 9 cases and bloodstream infections in a further 9. In multivariate analysis, independent predictors of infection during ECMO were the preoperative creatinine level (hazard ratio [HR], 2.176; 95% confidence interval [CI], 1.065-4.447; P = 0.033) and the duration of ECMO support (HR, 1.400; 95% CI, 1.081-1.815; P = 0.011). A higher preoperative creatinine level and an extended duration of ECMO support are risk factors for infection. Therefore, to avoid the development of nosocomial infections, strategies to shorten the length of ECMO support should be applied whenever possible.

Postoperative air leak grading is useful to predict prolonged air leak after pulmonary lobectomy.

BACKGROUND: Results of studies to predict prolonged air leak (PAL; air leak longer than 5 days) after pulmonary lobectomy have been inconsistent and are of limited use. We developed a new scale representing the amount of early postoperative air leak and determined its correlation with air leak duration and its potential as a predictor of PAL. METHODS: We grade postoperative air leak using a 5-grade scale. All 779 lobectomies from January 2005 to December 2009 with available medical records were reviewed retrospectively. We devised six 'SUM' variables using air leak grades in the initial 72 h postoperatively. RESULTS: Excluding unrecorded cases and postoperative broncho-pleural fistulas, there were 720 lobectomies. PAL occurred in 135 cases (18.8%). Correlation analyses showed each SUM variable highly correlated with air leak duration, and the SUM4to9, which was the sum of six consecutive values of air leak grades for every 8 h record on postoperative days 2 and 3, was proved to be the most powerful predictor of PAL; PAL could be predicted with 75.7% and 77.7% positive and negative predictive value, respectively, when SUM4to9 ≥ 16. When 4 predictors derived from multivariable logistic regression of perioperative variables were combined with SUM4to9, there was no significant increase in predictability compared with SUM4to9 alone. CONCLUSIONS: This simple new method to predict PAL using SUM4to9 showed that the amount of early postoperative air leak is the most powerful predictor of PAL, therefore, grading air leak after pulmonary lobectomy is a useful method to predict PAL.