Short-term outcomes of robotic subxiphoid-optical thymectomy.

PURPOSE: To evaluate the usefulness of robotic subxiphoid-optical thymectomy (RST). METHODS: Thirty-seven procedures (thymoma, n = 19; thymic carcinoma, n = 1; myasthenia gravis, n = 3; and others, n = 14) performed between October 2020 and December 2023 were included. The right and left 6th intercostal midclavicular lines and subxiphoid, with an assistant port placed in the right third intercostal anterior axillary line, were adapted. Postoperative pain was assessed using a numerical rating scale (NRS). RESULTS: A good view of the surgical field is obtained. The median console time was 113 min and the time to roll-in was 30 min. The body mass index (BMI) was 21.6. One patient with thymic carcinoma required combined resection of the left phrenic nerve and left brachiocephalic vein without conversion to thoracotomy, and 1 patient had post-pericardiotomy syndrome with bilateral pleural effusion. There was a correlation between the prolonged time to roll-in and BMI (ρ = 0.439; p = 0.007). Pain was controlled with oral medication on postoperative day 1 and significantly decreased at discharge and at the first outpatient visit without epidural anesthesia (median NRS scores: 4, 1, and 1, respectively). CONCLUSION: RST is a safe procedure that provides surgeons with a sufficient view of the anterior mediastinum and causes minimal postoperative pain.

Non-stapling thoracoscopic surgery for spontaneous pneumothorax in young patients.

OBJECTIVES: Spontaneous pneumothorax in young patients has a high recurrence rate, even after surgical treatment, and bulla neogenesis around stapled lesions has been reported as a cause of postoperative recurrence. We investigate the clinical safety and long-term outcome of non-stapling thoracoscopic surgery for spontaneous pneumothorax in young patients. METHODS: Twenty-seven non-stapling thoracoscopic surgeries for pneumothorax in 24 patients younger than 25 years were retrospectively reviewed. The non-stapling surgical techniques used to treat bullae included thoracoscopic suture plication, soft-coagulation, covering, and ligation. Long-term follow-up was conducted by telephone or by a mailed questionnaire. RESULTS: In 22 (81.5%) operations, suture plication, soft-coagulation, and covering procedures were used in combination. The median number of bullae treated in one operation was 2 (range, 0-6). The median operative time was 97 min, and the median postoperative drainage and postoperative hospital stay periods were 1 and 3 days, respectively. No complications of grade 2 or higher were observed. Patients were followed for at least 30 (median, 37) months. The postoperative recurrence rate was 3.7%, with one case of recurrence due to bulla neogenesis at a distant site. CONCLUSION: Non-stapling thoracoscopic surgery with covering procedure for pneumothorax in young patients might reduce postoperative recurrence.

Characteristic differences in the abundance of tumor-infiltrating lymphocytes and intratumoral developing T cells in thymoma, with special reference to PD-1 expression.

PURPOSE: Though programmed cell death-1 (PD-1) inhibitors mainly target tumor-infiltrating lymphocytes (TILs) expressing PD-1, developing T cells in thymus also express PD-1 in their process of maturation. To predict the therapeutic effect of PD-1 inhibitors for thymoma, it is necessary to clarify the proportions of TILs and intratumoral developing T cells. METHODS: The expressions of CD4, CD8, and PD-1 on T cells were analyzed by flow cytometry in 31 thymomas. The amount of T cell receptor excision circles (TRECs), which can be detected in newly formed naïve T cells in the thymus, was evaluated using sorted lymphocytes from thymomas by quantitative PCR. The expressions of granzyme B (GZMB) and lymphocyte activation gene-3 (LAG-3) in PD-1 + CD8 T cells were analyzed by image cytometry using multiplex immunohistochemistry. RESULTS: The PD-1 + rate in both CD4 and CD8 T cells was significantly higher in type AB/B1/B2 than in type A/B3 thymomas. The amounts of TRECs in CD4 and CD8 T cells were significantly higher in type AB/B1/B2 than in type A/B3 thymomas and comparable to normal thymus. PD-1 expression at each stage of T cell development of type AB/B1/B2 thymomas was comparable to that of normal thymus. Both the percentages and cell densities of PD-1 + CD8 T cells expressing GZMB or LAG-3, which are known to contain tumor-reactive T cells, were significantly lower in type AB/B1/B2 thymomas. CONCLUSION: Most PD-1 + T cells in type AB/B1/B2 thymomas are intratumoral developing T cells and are not TILs.

[Robot-assisted Segmentectomy for Lung Cancer].

The role of segmentectomy for lung cancer is expected to increase owing to the results of Japan Clinical Oncology Group (JCOG) 0802. Moreover, the major advantage of robot-assisted thoracic surgery (RATS) is that it allows high precision of dissection. The surgical approach comprised the placement of four robotic ports on the lower intercostal space with an assistant hole. While performing robotic surgery without haptic sensation, it is considered safe to dissect the bronchus first followed by the interlobar and intersegmental plane dissection at the end. In our institution, 52 lung cancer segmentectomies were performed between April 2020 and April 2022, out of which 8 (15.4%)were robot-assisted. The median operating time and console time for RATS were 233 and 182 minutes, respectively, showing a trend towards significantly longer operating time as compared to thoracoscopic segmentectomy( 184 vs. 233 minutes, p=0.007). There were no significant differences in the time to drain removal, the incidence of complications, or pain scores at discharge. Although robotic surgery provides the surgeon with better view and greater precision, it does not decrease the operation time and pain. However, robot-assisted surgery is expected to deliver greater benefits to the patient with technological advances in devices and surgical techniques.

Surgical intervention for non-small-cell lung cancer with minimal malignant pleural effusion.

PURPOSE: We assessed the clinical significance of minimal malignant pleural effusion (MPE) using liquid-based cytology (LBC) and immunocytochemistry and reviewed the postoperative outcomes of patients with non-small-cell lung cancer (NSCLC). METHODS: We reviewed 240 patients with cM0 NSCLC who underwent lobectomy. Carcinoembryonic antigen (CEA) immunocytochemistry was performed with LBC to aid in the diagnosis of minimal MPE. We assessed the efficacy of this diagnostic method, relevant clinical factors, and postoperative outcomes. RESULTS: LBC showed positive results in two patients and suspicious results in 21. Of the 21 patients, immunocytochemistry showed minimal MPE in 10 (47.6%); therefore, a total of 12 patients (5%) showed minimal MPE. Minimal MPE is associated with an older age, increased consolidation tumor ratio, and adenocarcinoma histology. The 12 patients with minimal MPE had a 3-year overall survival rate of 90%. Postoperative recurrence was observed in seven patients (58.3%), four of whom were treated with epidermal growth factor receptor-tyrosine kinase inhibitors or immune checkpoint inhibitors, while three are still undergoing treatment, with a survival of 2.2, 2.5 and 5.5 years. CONCLUSIONS: CEA immunocytochemistry offers high sensitivity for the diagnosis of minimal MPE. Surgical intervention may be considered for select patients with NSCLC showing minimal MPE.

Spread through air spaces is a powerful prognostic predictor in patients with completely resected pathological stage I lung adenocarcinoma.

PURPOSE: To evaluate the frequency of spread through air spaces (STAS) in patients with early-stage primary lung cancer and to elucidate the association between STAS and various clinicopathological factors. METHODS: We retrospectively reviewed data from a total of 265 consecutive patients who underwent lobectomy and mediastinal lymph node dissection (172 patients) or sublobar resection (93 patients) for completely resected pathological stage I lung adenocarcinoma. We evaluated clinical variables, including the preoperative serum carcinoembryonic antigen (CEA) level, tumour size, consolidation tumour ratio (CTR), maximum standardized uptake value (SUVmax) on FDG-PET, histological results, presence of STAS and vascular and lymphatic invasion. RESULTS: The median follow-up time after surgery was 49 months. Eighty-seven patients (32.8 %) had STAS. The overall survival rates of patients in the STAS-positive and STAS-negative groups were 92.7 % and 97.1 % at 3 years, respectively (p = 0.1255), and the recurrence-free survival rates were 82.1 % and 95.9 % at 3 years, respectively (p = 0.0001). STAS was found in 73 patients (42.4 %) in the lobectomy group, which was a significantly higher proportion than the 14 patients (15.1 %) in the sublobar resection group. The STAS-positive group had significantly larger areas of invasion, higher CTRs, preoperative CEA and SUVmax levels, and more lymphatic and vascular invasion. STAS also correlated significantly with large consolidation sizes, larger invasive size, higher CTRs and the presence of a micropapillary pattern. Cox regression analysis after adjustment for important prognostic factors revealed that the presence of STAS was an independent predictor associated with postoperative recurrence, most of which was observed locoregionally. CONCLUSIONS: STAS was an independent factor associated with postoperative recurrence after lung resection for stage I lung adenocarcinoma. Among stage IA patients, the postoperative outcomes of STAS-positive patients were worse than those of STAS-negative patients and were similar to those of stage IB patients.

Prognostic Impact of Using Combined Plasma Fibrinogen Level and Neutrophil-to-Lymphocyte Ratio in Resectable Non-small Cell Lung Cancer.

BACKGROUND: Both plasma fibrinogen level and neutrophil-to-lymphocyte ratio (NLR) are associated with malignant potential in different cancer types. The current study evaluated the use of combined plasma fibrinogen level and NLR (F-NLR) as a prognostic predictor in patients with non-small cell lung cancer (NSCLC). METHODS: Data collected from 279 patients with resectable NSCLC were retrospectively reviewed. Patients were divided into three groups based on the F-NLR score: score 2, high fibrinogen level (≥350 mg/dL) and high NLR (≥2.5); score 1, either high fibrinogen level or high NLR; and score 0, neither abnormal. Overall survival (OS) and relapse-free survival (RFS) were evaluated using the Kaplan-Meier method and log-rank test. Cox proportional hazard model was used to assess prognostic factors. RESULTS: Numbers of patients with F-NLR score of 0, 1, and 2 were 122 (43.7%), 105 (37.6%), and 52 (18.6%), respectively. The F-NLR was found to be significantly associated with age, male sex, heavy smoking history, high pT status and pathological stage, and nonadenocarcinoma. Moreover, the OS and RFS significantly differed according to the F-NLR score (P < 0.001, P = 0.003). A multivariate analysis revealed that a high F-NLR score (≥1) was an independent poor prognostic factor for OS (P = 0.027). In subgroup analyses, an adverse prognostic impact of the F-NLR score on OS was identified regardless of nodal involvement or pathological stage. CONCLUSIONS: The F-NLR score, which is based on histological inflammation and coagulability, could be a potential prognostic indicator in patients with resectable NSCLC.

Clinical significance of postoperative pulmonary complications in elderly patients with lung cancer.

OBJECTIVES: An increasing number of elderly patients with impaired immunity, malnutrition and comorbidities are considered surgical candidates. This study aimed to clarify the predictive factors and prognostic impact of postoperative pulmonary complications in elderly patients with lung cancer. METHODS: This retrospective study included 188 patients (≥75 years) who underwent complete anatomical lung resection for non-small cell lung cancer between 2005 and 2019. Postoperative pulmonary complications graded ≥II in the Clavien-Dindo classification, occurring within 30-day post-surgery were evaluated. Multivariate logistic regression analyses and Cox proportional hazard models were used to analyse predictors and prognostic impact of complications. RESULTS: Video-assisted thoracoscopic surgery was performed in 154 patients (81.9%). The 90-day mortality rate was 0.5%. Postoperative pulmonary complications including air leak, pneumonia, sputum retention, atelectasis, bronchopleural fistula and empyema occurred in 29 patients (15.4%). A lower prognostic nutritional index (<45) and longer operative time were independent predictive factors of pulmonary complications, with 33.3% of patients experiencing both factors. Following a median follow-up of 48 months, the 5-year overall and relapse-free survival rates were significantly worse in patients with pulmonary complications than in those without them (54.4% vs 81.5% and 41.2% vs 74.9%). Pulmonary complications were significantly associated with worse overall and relapse-free survival [hazard ratio (95% confidence interval): 1.97 (1.01-3.66), P = 0.047 and 2.35 (1.28-4.12), P = 0.007, respectively] along with pathologic stage and carcinoembryonic antigen levels. CONCLUSIONS: Postoperative pulmonary complications are associated with a lower prognostic nutritional index and prolonged operative time; the complications are independent adverse prognostic factors in elderly patients.

Robotic subxiphoid-optical thymectomy.

Robot-assisted thymectomy through a subxiphoid scopic approach can provide a good surgical view, similar to that of median sternotomy. We originally used the subxiphoid port only for the robotic scope to avoid instrument collision with the assistant device. This approach, robotic subxiphoid-optical thymectomy, is advantageous for the safe and accurate dissection of the bilateral phrenic nerves and the left brachiocephalic vein, which are especially needed in extended thymectomy for patients with myasthenia gravis.

A clinicopathologic and molecular analysis of five cases of bronchiolar adenoma with rare mutations.

Bronchiolar adenoma (BA) is a rare benign lung tumor that shows proliferation of bland bronchiolar-type epithelium containing a continuous layer of basal cells. This tumor entity has been newly added to the recent World Health Organization (WHO) classification 5th edition. This entity encompasses a spectrum of lesions: the classic ciliated muconodular papillary tumor (CMPT) and the non-classic CMPT. Although BA is reported to have driver mutations including BRAF V600E, EGFR, and KRAS, the molecular profile of BA is still incompletely understood. Five resected BAs at our institutions were analyzed. The BA lesions were subdivided into two groups: three proximal-type BAs and two distal-type BAs. NRAS codon 12/13 mutation and EML4 exon 20-ALK exon 20 fusion were found in two of the three proximal-types. BRAF V600E mutation was found in one of the two distal-types. Two cases coexisted with lung adenocarcinoma, with EGFR exon 19 deletion and KRAS mutation, respectively. No recurrence was observed at a median of 12 months (range 2-84 months) of follow-up. BA has uncommon variants of mutation seen in lung adenocarcinoma. NRAS mutation and ALK fusion partner has not been reported previously. The present cases may reinforce the distinctive biology of BA from lung adenocarcinoma.

Endoscopic Surgery Using Ultrasonic Energy Device for Tracheal Metastatic Tumor.

We describe a rare case of tracheal metastasis from endometrial carcinoma obstructing the central airway. A 57-year-old woman who underwent previous surgery for endometrial serous adenocarcinoma presented with severe tracheal stenosis caused by a stalked tracheal tumor. Urgent debulking surgery was performed under rigid bronchoscopy. The tumor stem was dissected using ultrasonically activated device blades. Rigid bronchoscopy combined with an ultrasonically activated device is an effective option for relieving tracheal stenosis and resecting the intratracheal tumor.

Volume-Based Consolidation-to-Tumor Ratio Is a Useful Predictor for Postoperative Upstaging in Stage I and II Lung Adenocarcinomas.

BACKGROUND: We investigated the postoperative upstaging of stage I and II lung adenocarcinoma patients to identify useful predictors for accurate staging. METHODS: We retrospectively reviewed data from 80 consecutive patients undergoing lobectomy and mediastinal lymph node dissection for clinical stage I and II lung adenocarcinomas. We evaluated clinical variables, including the preoperative serum carcinoembryonic antigen (CEA), tumor diameter, consolidation-to-tumor ratio (CTR), maximum standardized uptake value (SUVmax) on FDG- PET, expression of epithelial growth factor receptor mutations, and pathological invasion to the pleura (pl), lymph duct (ly), and vein (v). RESULTS: Eleven patients (13.8%) showed postoperative upstaging. Three cases had pN1 migrating from cN0, four cases had pN2 from cN0, and four cases showed malignant pleural effusion. The CEA level and CTR were significantly higher in the upstaging group. The tumors in the upstaging group showed more frequent pathological invasion to the visceral pleura and vein. In patients with 3 cm or smaller consolidation, two-dimensional (2D)-CTR and volume-based CTR were independent predictors of upstaging. CONCLUSIONS: Volume-based CTR could be a useful predictor for accurate clinical staging in stage I and II adenocarcinoma patients in addition to consolidation size, serum CEA level, and 2D-CTR. Both volume-based and 2D-CTRs might be especially useful in T1 diseases.

Life-threatening extrapleural hematoma in an anticoagulated patient 2 weeks after lobectomy.

We report a case of an anticoagulated patient with sudden onset pleural hematoma after straining at defecation to cardiac arrest on 2 weeks after lobectomy for lung cancer. We decided to perform an emergent operation for an evacuation of extrapleural hematoma immediately after resuscitation. The bleeding point was revealed on the extrapleural thoracic apex. We should be aware that extrapleural hematoma can occur because of increased intrathoracic pressure such as straining during defecation in patients on anticoagulation.

Negative-pressure wound therapy in combination with bronchial occlusion to treat bronchopleural fistula: a case report.

BACKGROUND: Bronchopleural fistula, which usually accompanies bronchial fistula and empyema, is a severe complication of lung cancer surgery. Negative-pressure wound therapy can enhance drainage and reduce the empyema cavity, potentially leading to early recovery. This therapy is not currently indicated for bronchopleural fistulas because of the risk of insufficient respiration due to air loss from the fistula. CASE PRESENTATION: A 73-year-old man, who was malnourished because of peritoneal dialysis, was referred to our hospital for the treatment of lung cancer. Right lower lobectomy with mediastinal lymph node dissection was performed via posterolateral thoracotomy, and the bronchial stump was covered with the intercostal muscle flap. His postoperative course was uneventful and he was discharged. However, he was readmitted to our hospital because of respiratory failure and diagnosed as having bronchopleural fistula on the basis of the bronchoscopic finding of a 10-mm hole at the membranous portion of the inlet of the remnant lower lobe bronchus. Thus, thoracotomy debridement and open window thoracostomy were immediately performed. After achieving infection control, bronchial occlusion was performed using fibrin glue and a polyglycolic acid sheet was inserted through a fenestrated wound. Bronchial fistula closure was observed on bronchoscopy; therefore, a negative-pressure wound therapy system was applied to close the fenestrated wound. The collapsed lung was re-expanded and the granulation tissue around the wound increased; therefore, thoracic cavity size decreased and thoracoplasty using the latissimus dorsi was performed. CONCLUSIONS: This bronchopleural fistula was treated successfully after a right lower lobectomy using an extra-pleural bronchial occlusion and negative-pressure wound therapy.

[Surgical Strategy for Multiple Synchronous Primary Lung Cancer Showing Ground Glass Opacities:Percutaneous Preoperative Computed Tomography-guided Lipiodol Marking Followed by Video-assisted Thoracic Surgery].

From May 2006 to March 2018, a total of 30 patients with multiple ground glass opacities( GGO) lessor equal to 2.0 cm underwent percutaneous preoperative computed tomography (CT)-guided Lipiodolmarking and subsequent video-assisted thoracic surgery( VATS). There were 22 patients with 2 GGOs,6 patients with 3 GGOs, 1 patient with 4 GGOs, and 1 patient with 5 GGOs. Of the 71 CT-guided Lipiodolmarking procedures were successfully completed. All 71 Lipiodol spots were detected with C-armshapedfluoroscopy and completely resected. Pneumothorax was the most common complication andoccurred in 22 (73.3%) of 30 cases. There were severe complications in two (6.7%) cases of pneumothoraxrequiring chest tube placement and three( 10.0%) cases of bloody sputum. Of 30 cases multipleGGOs revealed 24 synchronous lung cancer (19 patients with double lung cancer, 3 patients with triplelung cancer, 1 patient with quadruple lung cancer, and 1 patient with quintuple lung cancer). PreoperativeCT-guided lipiodol marking and VATS resection is a safe and reliable method for synchronous multiplelung cancer showing GGO.

Extrathoracic Superior Vena Cava Bypass With Venous Return Cannulas in Malignant Mediastinal Tumor Surgery.

Combined resection of the superior vena cava is sometimes challenging during radical surgery for malignant mediastinal tumors. We report a case of a 21-year-old man with a malignant mediastinal germ cell tumor who underwent surgical resection with superior vena cava reconstruction involving an extrathoracic temporary bypass from the right brachiocephalic vein to the right atrium using a venous return cannula because of left brachiocephalic vein occlusion. This is a convenient and safe optional technique providing an excellent intrathoracic surgical view for temporary superior vena cava bypass in patients with invasive malignant mediastinal tumor associated with venous return through the hemilateral brachiocephalic vein.

One-stage closure of large bronchopleural fistula with pedicled latissimus dorsi muscle flap after preemptive antibiotics: A case report.

INTRODUCTION: Bronchopleural fistula (BPF) after lung cancer surgery is a life-threatening complication and often needs two-stage closure after fenestration. Although one-stage closure of BPF is challenging, it would provide shorter treatment time and lower patient physical burden than two-stage closure. However, there have been few reports of one-stage closure of a large BPF. PRESENTATION OF CASE: A 53-year-old man underwent robotic right lower lobectomy with systematic lymph node dissection. Postoperative bronchoscopy revealed an ischemic change in the bronchial stump, which progressed to a large BPF. However, under the preemptive antibiotic treatment without chest drainage, local infection was controlled within a limited pleural space. We successfully performed one-stage closure of a 3-cm sized BPF with pedicled latissimus dorsi (PLD) muscle flap. DISCUSSION: Early diagnosis of ischemic bronchitis and appropriate preceding antibiotic treatment could minimize the local infection around the fistula. To our knowledge, our case represented the largest BPF that was successfully treated by one-stage procedure using preemptive antibiotics and the PLD muscle flap. CONCLUSION: One-stage closure using the PLD muscle flap may be a treatment option even for a 3-cm sized BPF, wherein infection is controlled and the relevant pleural cavity is limited.

Prognostic significance of spread through air spaces in pulmonary metastases from colorectal cancer.

OBJECTIVES: Surgical resection for pulmonary metastases from colorectal cancer could provide long-term survival in selected patients, and it is commonly performed in practice. However, surgical margin relapse sometimes occurs and is a problematic issue to resolve. Spread through air spaces (STAS) is one of the invasion forms in primary lung cancer and is associated with local recurrence and a poor prognosis. The aim of this study was to evaluate the prognostic significance of STAS for pulmonary metastases from colorectal cancer and to assess the predictability of STAS with preoperative clinical information. METHODS: A total of 96 pulmonary metastatic lesions from colorectal cancer in 37 patients who underwent metastasectomy at our institution from January 2008 to December 2013 were retrospectively analyzed. RESULTS: STAS was identified in 41.6 % of the 96 lesions. Surgical margin relapse was found in 8 lesions (8.3 %) from 7 patients (18.9 %). The distance of STAS was identified as an independent risk factor for surgical margin relapse on multivariable analysis (p =  0.033). The patients with STAS showed significantly worse overall survival than those without (5-year overall survival rate: 30.3 % vs. 76.9 %; p =  0.002). On multivariable analysis, patients with STAS had a significantly higher risk of death than those without (p =  0.019). An elevated pre-metastasectomy serum carcinoembryonic antigen level was independently correlated with STAS on multivariable analysis (p =  0.049). CONCLUSION: STAS was related to a poor prognosis and surgical margin relapse in pulmonary metastases from colorectal cancer.

Programmed death-ligand 1 expression profiling in thymic epithelial cell tumors: Clinicopathological features and quantitative digital image analyses.

OBJECTIVES: Whether the extent of expression of programmed death-ligand 1 (PD-L1) is clinically significant remains uncertain, although immuno-oncological features have been studied in thymic epithelial cell tumors (TETs). We investigated the histological features of PD-L1 expression in TETs, and assessed PD-L1 expression using digital image analysis. MATERIALS AND METHODS: Participants comprised 66 patients with TET who underwent surgical resection between 2001 and 2016. We calculated tumor cell-positive ratio as total proportion score (TPS) with immunohistochemistry using SP263 anti-PD-L1 monoclonal antibody. PD-L1 expression was also quantified using digital image analysis of whole-slide images. We evaluated the relationship between conventional visual TPS using optical microscopy (TPS-V) and TPS from digital image analysis (TPS-IA). We further classified all TETs into high or low PD-L1 expression groups and assessed the clinical significance of PD-L1 expression level using TPS-V and TPS-IA. RESULTS: WHO histological types were Type A (n = 8), AB (n = 18), B1 (n = 5), B2 (n = 16), B3 (n = 6), metaplastic thymoma (n = 2), and thymic carcinoma (TC) (n = 11). Median TPS-Vs were 2%, 2%, 10 %, 65 %, 90 %, 1%, and 20 %, respectively. TPS-IAs correlated with TPS-Vs in TETs overall and in thymomas, but not in TCs. PD-L1 expression levels in TETs differed significantly among histological types. Whether TPS-V or TPS-IA were used, the PD-L1high group included more cases of the more aggressive histological types. Recurrence-free survival (RFS) was shorter in the PD-L1high group than in the PD-L1low group in thymoma using TPS-IA, whereas RFS of the PD-L1high group was shorter in all TETs using TPS-V. CONCLUSION: PD-L1 expression levels depended on the histological type of TET. Extensive PD-L1 expression in TETs was associated with poor prognosis. Digital image analysis is feasible for evaluating PD-L1 expression in TETs and might offer clinically relevant features of thymomas.