Simple Aspiration versus Drainage for Complete Pneumothorax: A Randomized Noninferiority Trial.

Rationale: Management of first episodes of primary spontaneous pneumothorax remains the subject of debate. Objectives: To determine whether first-line simple aspiration is noninferior to first-line chest tube drainage for lung expansion in patients with complete primary spontaneous pneumothorax. Methods: We conducted a prospective, open-label, randomized noninferiority trial. Adults aged 18-50 years with complete primary spontaneous pneumothorax (total separation of the lung from the chest wall), recruited at 31 French hospitals from 2009 to 2015, received simple aspiration (n = 200) or chest tube drainage (n = 202) as first-line treatment. The primary outcome was pulmonary expansion 24 hours after the procedure. Secondary outcomes were tolerance of treatment, occurrence of adverse events, and recurrence of pneumothorax within 1 year. Substantial discordance in the numerical inputs used for trial planning and the actual trial rates of the primary outcome resulted in a reevaluation of the trial analysis plan. Measurement and Main Results: Treatment failure occurred in 29% in the aspiration group and 18% in the chest tube drainage group (difference in failure rate, 0.113; 95% confidence interval [CI], 0.026-0.200). The aspiration group experienced less pain overall (mean difference, -1.4; 95% CI, -1.89, -0.91), less pain limiting breathing (frequency difference, -0.18; 95% CI, -0.27, -0.09), and less kinking of the device (frequency difference, -0.05; 95% CI, -0.09, -0.01). Recurrence of pneumothorax was 20% in this group versus 27% in the drainage group (frequency difference, -0.07; 95% CI, -0.16, +0.02). Conclusions: First-line management of complete primary spontaneous pneumothorax with simple aspiration had a higher failure rate than chest tube drainage but was better tolerated with fewer adverse events. Clinical trial registered with www.clinicaltrials.gov (NCT01008228).

Value of immunohistochemistry in crushed areas of pulmonary neuroendocrine carcinoma.

Immunohistochemical demonstration of neuroendocrine differentiation is often performed in routine diagnostic practice for lung neuroendocrine carcinoma. However, these carcinomas are often crushed, especially on small specimens. The value of immunohistochemistry on crushed areas is not known. We aimed to assess the value of immunohistochemical markers in crushed areas. We performed a retrospective study of 299 patients with a diagnosis of pulmonary neuroendocrine carcinoma. We showed that the markers TTF-1, synaptophysin, chromogranin A, CD56, and INSM1 were more often negative in crushed areas compared with well-preserved areas. The proliferation index with anti-Ki67 was decreased but remained on average around 90%. For all markers, the percentage of labeled cells was lower than in the preserved areas. Finally, we show that cases without labeling in the crushed areas and maintained labeling in the non-crushed areas have a lower percentage of labeling than cases without this labeling mismatch. Finally, there were no false positives of these stains. Neuroendocrine markers are valid in crushed areas when positive. However, the percentage of labeled cells may be lower than on preserved areas and lead to false negatives. Finally, the proliferation index, although decreased, remains close to that on preserved areas.

Histopathological and molecular profiling of lung adenocarcinoma skin metastases reveals specific features.

AIMS: Little is known regarding the histopathological and molecular features of lung adenocarcinoma skin metastases. Our study is the largest, to our knowledge, to comprehensively explore these to date. METHODS AND RESULTS: We performed a retrospective cohort study analysing 42 lung adenocarcinoma skin metastasis samples obtained from a database of 2659 lung adenocarcinomas collected between 2010 and 2020. EGFR exon 19 deletion was detected in one patient and KRAS mutations were detected in 12 (33.3%) patients. The programmed cell death ligand 1 (PD-L1) tumour proportion score was <1% in 27 patients, ≥1% and <50% in eight patients, ≥50% in six patients and not assessable in one patient. We showed that the predominant histopathological subtype is different from that at other metastatic sites (P = 0.024). Thyroid transcription factor I (TTF-1) was more often negative in skin metastases compared to other sites (P < 0.001). The EGFR mutation rate tended to be lower for skin metastases compared to other sites (P = 0.079). Skin metastases were associated with a high rate of PD-L1-negative cases (P = 0.022). CONCLUSION: Our work shows that the skin metastases of lung adenocarcinoma have a specific histopathological profile.

Medical and Economic Evaluation of FOREseal Bioabsorbable Reinforcement Sleeves Compared With Current Standard of Care for Reducing Air Leakage Duration After Lung Resection for Malignancy: A Randomized Trial.

OBJECTIVE: The objective of this study was to determine the efficacy of alginate staple-line reinforcement of fissure openings as compared with stapling alone, with or without tissue sealant or glue, in reducing the incidence and duration of air leakage after pulmonary lobectomy for malignancy. SUMMARY BACKGROUND DATA: No randomized trial evaluating alginate staple-line reinforcement has been performed to date. METHODS: The Staple-line Reinforcement for Prevention of Pulmonary Air Leakage study was a multicenter randomized trial, with blinded evaluation of endpoints. Patients over 18 years of age scheduled for elective open lobectomy or bilobectomy for malignancy were eligible for enrollment. At thoracotomy, patients were deemed ineligible if an unanticipated pneumonectomy was indicated, or if air leakage occurred after the liberation of pleural adhesions. Otherwise, if the fissure was incomplete or the lung had an emphysematous appearance, patients were randomized to either standard management or interventional procedure consisting of fissure opening with linear cutting staplers buttressed with paired alginate sleeves (FOREseal). The number of eligible patients necessary in each randomization arm was estimated to be 190, and an outcomes analysis was performed on an intention-to-treat basis. RESULTS: Of the 611 patients consented to study enrollment, 380 met the inclusion criteria and were randomized. Based on an intention-to-treat analysis, the primary endpoint of air leak duration was not different between the 2 groups: 1 day (range: 0-2 d) in the FOREseal group and 1 day (range: 0-3 d) in the control group (P = 0.8357). In addition, the 2 groups were similar in terms of the proportion of patients presenting with prolonged air leakage (7.8% in the FOREseal group vs 11.3% in the control group, P = 0.264) and the average duration of chest drainage (P = 0.107). Procedure costs were comparable for both groups. CONCLUSIONS: FOREseal did not demonstrate a significant advantage over standard treatment alone.

Frozen Sections in Pleural Pathology: A Valuable Tool.

BACKGROUND: Knowledge of pleural malignancy can lead to immediate pleurodesis during thoracoscopy. However, the accuracy of pleural frozen sections is largely unknown. OBJECTIVES: To investigate the accuracy of frozen sections in pleural tumor pathology. METHODS: A total of 156 frozen pleural sections performed with the question of malignancy were retrospectively reviewed. The original frozen sections were compared to the permanent section slides which were considered as the gold standard. The influence of the following parameters on the frozen section response was evaluated: specimen size, clinical information, as well as the processing by a specialized pulmonary pathologist or not. The reasons of discrepancies were categorized as sampling errors or interpretation errors. RESULTS: Frozen sections made up 16.4% of 951 pleural biopsies performed in the same time period. Accurate diagnosis was feasible in 92.3% of the cases. There were 7 (4.5%) deferred (inconclusive) cases and 5 (3.2%) discrepant cases. Sensitivity of the method was 96.26%, specificity 97.87%, the positive predictive value was 99.04%, and the negative predictive value was 92%. There was no association between the responses given during frozen section and specimen size, clinical information, or the evaluation by a specialized pulmonary pathologist. Four of the 12 cases were sampling errors, while 8 cases were interpretation errors mostly made in the absence of fat tissue invasion. Thus, paucicellular lesions without prominent invasion - fat invasion or haphazardly invading cellular proliferation - were those posing most of the difficulties during frozen section. CONCLUSIONS: Frozen sections are a highly accurate tool in pleural pathology. Thus, they can be used when an immediate pleurodesis is requested.

Combined Minimally Invasive Redo Mitral Surgery and Pectus Excavatum Correction.

We present a technique of mitral valve surgery performed in a patient with severe pectus excavatum and previous Bentall surgery. Neither redo sternotomy nor conventional right minithoracotomy were thought to provide adequate surgical access to the mitral valve. We therefore opted for a combined procedure comprising sternal reconstruction and right minithoracotomy mitral valve replacement. The mitral valve was replaced and the sternum reconstructed according to the Ravitch technique.

Laparoscopic Hernia Repair With 3-Millimeter Instruments: A Point of Technique and Illustrative Case Video.

The repair of inguinal hernia has been a controversial issue in surgical practice since its conception. The article demonstrates that use of 3 mm instruments can be incorporated in Laparoscopic hernia repair. The second aim of this article is that use of TAP block (Transverse abdominal plane block) without curare is efficient, safe and reproducible.

Outcome of patients with esophageal perforations: a multicenter study.

BACKGROUND: Recent studies have suggested that stent-grafting may improve the treatment outcome of patients with esophageal perforation, but evidence on this is still lacking. METHODS: Data on 194 patients who underwent conservative (43 patients), endoclip (4 patients) stent-grafting (63 patients) or surgical treatment (84 patients) for esophageal perforation were retrieved from nine medical centers. RESULTS: In-hospital/30-day mortality was 17.5 %. Three-year survival was 67.1 %. Age, coronary artery disease, and esophageal malignancy were independent predictors of early mortality. Chi squared automatic interaction detection analysis showed that patients without coronary artery disease, without esophageal malignancy and younger than 70 years had the lowest early mortality (4.1 %). Surgery was associated with slightly lower early mortality (conservative 23.3, endoclips 25.0 %, stent-grafting 19.0 %, surgery 13.1 %; p = 0.499). One center reported a series of more than 20 patients treated with stent-grafting which achieved an early mortality of 7.7 % (2/26 patients). Stent-grafting was associated with better survival with salvaged esophagus (conservative 76.7 %, endoclips 75.0 %, stent-grafting 77.8 %, surgery 56.0 %; p = 0.019). Propensity score adjusted analysis showed that stent-grafting achieved similar early mortality (p = 0.946), but significantly higher survival with salvaged esophagus than with surgical treatment (p = 0.001, OR 0.253, 95 % CI 0.110-0.585). Primary surgical repair was associated with somewhat lower early mortality (14.6 vs. 19.0 %; p = 0.561) and better survival with salvaged esophagus (85.4 vs. 77.8 %; p = 0.337) than stent-grafting. CONCLUSIONS: Esophageal perforation was associated with a rather high mortality rate in this all-comers population. Stent-grafting failed to decrease operative mortality, but it improved survival with salvaged esophagus. The results of one of the centers indicate that increasing experience with this less invasive procedure may possibly improve the outcome of these patients.

Spread Through Air Spaces in Stage I to III Resected Lung Adenocarcinomas: Should the Presence of Spread Through Air Spaces Lead to an Upstaging?

In recent years, the concept of spread through air spaces (STAS) has been discussed as an adverse prognostic factor for lung cancer. The aim of our study is to clarify the prognostic role of STAS in relation to the main recognized prognostic factors in a retrospective cohort of 330 European patients who underwent stages I to III lung adenocarcinoma resection. On univariate analysis, the presence of STAS was related to progression-free survival (PFS; hazard ratio [HR]: 1.48; 95% CI: 1.02-2.19; P = 0.038) and overall survival (OS; HR: 1.61; 95% CI: 1.03-2.52; P = 0.50). On multivariate analysis, STAS was related to PFS (HR: 1.51; 95% CI: 1.00-2.17; P = 0.050) and to OS (HR: 1.67; 95% CI: 1.00-2.81; P = 0.050). We showed that the presence of STAS was associated with lower PFS, equivalent to the next pathologic T stage, especially the median PFS of T3 stages without STAS was at 62.8 months while the median PFS of T3 stages with STAS was at 15.7 months, closer to the median PFS of 17.4 months in T4 stages. To conclude, STAS is an independent prognostic factor of PFS in this European cohort and is close to significance for OS. We suggest that the presence of STAS might lead to an upstaging of lung adenocarcinoma.

Prognostic role of immune microenvironment in pleural metastases from breast and lung adenocarcinomas.

Background: Pleural metastatic disease is a common disease with dismal prognosis. The immune microenvironment of metastatic pleural tissue remains largely unknown. Thus, we aimed to investigate the presence of different immune cell populations, and to compare them with clinical characteristics. Methods: We included 70 patients with lung and breast adenocarcinoma (ADC) diagnosed with pleural metastasis during a 2-year period with the primary endpoint to investigate if the main immune cell populations are present in pleural metastases and if they have any prognostic role. Secondary endpoints were to detect any differences in their presence between lung and breast primaries and to search for any correlation with the macroscopic (thoracoscopic) findings. We used immunohistochemical techniques for the detection of CD4+, CD8+, CD20+, CD163+ and S100+ cells in whole tissue pleural biopsies of lung and breast metastases. Results: Primary endpoint: all these populations are present in the biopsies from lung and higher stromal and intratumoral CD4 counts, as well as higher stromal CD20 cells were positive prognostic factors for lung cancer metastases, while higher S100 intratumoral counts were positive prognostic factors in lung and marginally breast cancer metastases. Secondary endpoints: significant higher values for the stromal CD163 group (P=0.04) and for the intratumoral S100 group (P=0.006) were seen in lung compared to breast metastases. Interesting correlations were also noted between thoracoscopic findings (nodules, masses, pachypleuritis) and the different factors studied. Conclusions: Our data show that the immune microenvironment may be important in this advanced tumoral setting and that possible targets of the nowadays numerous treatment strategies implicating the immune system may merit further exploration in this poor prognosis disease.

Spread Through Air Spaces (STAS) Is an Independent Prognostic Factor in Resected Lung Squamous Cell Carcinoma.

Objective: There is no histoprognostic grading for lung squamous cell carcinoma (LUSC). Different prognostic factors have been described in the recent literature and are not always studied in parallel. Our objective was to search for morphological histopathological prognostic factors in LUSC. Materials and Methods: In this single-center retrospective study of 241 patients, all patients with LUSC who underwent surgical excision over a 12-year period were included. The primary endpoint was 5-year overall survival. Results: STAS was present in 86 (35.7%) patients. The presence of Spread Through Air Spaces (STAS) was correlated with tumor location (p < 0.001), pathological stage (p = 0.039), tumor differentiation (p = 0.029), percentage of necrosis (p = 0.004), presence of vascular and/or lymphatic emboli, budding (p = 0.02), single cell invasion (p = 0.002) and tumor nest size (p = 0.005). The percentage of tumor necrosis was correlated with the overall survival at 5 years: 44.6% of patients were alive when the percentage of necrosis was ≥50%, whereas 68.5% were alive at 5 years when the necrosis was <30% (p < 0.001). When vasculolymphatic emboli were present, the percentage of survival at 5 years was 42.5% compared to 65.5% when they were absent (p = 0.002). The presence of isolated cell invasion was correlated with a lower 5-year survival rate: 51.1% in the case of presence, versus 66% in the case of absence (p = 0.02). In univariate analysis, performance status, pathological stage pT or pN, pleural invasion, histopathological subtype, percentage of tumor necrosis, vasculolymphatic invasion, single-cell invasion, budding and tumor nest size correlated with the percentage of survival at 5 years. On multivariate analysis, only STAS > 3 alveoli (HR, 2.74; 95% CI, 1.18−6.33) was related to overall survival. Conclusion: In conclusion, extensive STAS is an independent factor of poor prognosis in LUSC. STAS is correlated with the presence of other poor prognostic factors such as emboli and pleural invasion and would reflect greater tumor aggressiveness.

Preventive tract embolization with gelatin sponge slurry is safe and considerably reduces pneumothorax after CT-guided lung biopsy with use of large 16-18 coaxial needles.

OBJECTIVE: To evaluate the clinical impact of the tract embolization technique using gelatin sponge slurry after percutaneous CT-guided lung biopsy. METHODS: We retrospectively compared coaxial needle CT-guided lung biopsies performed without embolization (100 patients) and with the tract embolization technique using a mixture of iodine and gelatin sponge slurry (105 patients) between June 2012 and July 2020. Uni- and multivariate analyses were performed between groups to determine risk factors of pneumothorax. RESULTS: Patients with gelatin sponge slurry tract embolization had statistically lower rates of pneumothorax ((17.1% vs 39%, p < 0.001). In univariate analysis, tract embolization (OR = 0.32, CI = 0.17-0.61 p<0.001) and nodule size >2 cm (OR = 0.33 CI = 0.14-0.8 p = 0.013) had a protective effect on pneumothorax. The puncture path lengths > 2-20 mm and >20 mm were risk factors for pneumothorax (OR = 3.35 IC = 1.44-8.21 p = 0.006 and OR = 4.36 CI = 1.98-10.29 p<0.001, respectively). In multivariate regression analysis, tract embolization had a protective effect of pneumothorax (OR = 0.25, CI = 0.12-0.51, p < 0.001). The puncture path lengths > 2-20 mm and >20 mm were risk factors for pneumothorax (p = 0.030 and p = 0.002, respectively). CONCLUSIONS: The tract embolization technique using iodinated gelatin sponge slurry is safe and considerably reduces pneumothorax after percutaneous CT-guided lung biopsy. Our results suggest that it could be use in clinical routine. ADVANCES IN KNOWLEDGE: The systemic use of gelatin sponge slurry is safe and reduces considerably the rate of pneumothorax upon needle removal when CT-guided core biopsies are performed using large 16-18G coaxial needles.

Superior vena cava graft infection in thoracic surgery: a retrospective study of the French EPITHOR database.

OBJECTIVES: To report our experience on the management of superior vena cava graft infection. METHODS: Between 2001 and 2018, patients with superior vena cava synthetic graft or patch reconstruction after resection of intrathoracic tumours or benign disease were selected retrospectively from the French EPITHOR database and participating thoracic centres. Our study population includes patients with superior vena cava graft infection, defined according to the MAGIC consensus. Superior vena cava synthetic grafts in an empyema or mediastinitis were considered as infected. RESULTS: Of 111 eligible patients, superior vena cava graft infection occurred in 12 (11.9%) patients with a polytetrafluoroethylene graft secondary to contiguous contamination. Management consisted of either conservative treatment with chest tube drainage and antibiotics (n = 3) or a surgical graft-sparing strategy (n = 9). Recurrence of infection appears in 6 patients. Graft removal was performed in 2 patients among the 5 reoperated patients. The operative mortality rate was 25%. CONCLUSIONS: Superior vena cava graft infection may develop as a surgical site infection secondary to early mediastinitis or empyema. Graft removal is not always mandatory but should be considered in late or recurrent graft infection or in infections caused by aggressive microorganisms (virulent or multidrug resistant bacteria or fungi).

Adjuvant chemotherapy for completely resected IIA-IIIA non-small cell lung cancer: compliance to guidelines, safety and efficacy in real-life practice.

Background: Since randomised clinical trials demonstrated a survival benefit of adjuvant chemotherapy (AC) following curative-intent lung surgery, AC has been implemented as a standard therapeutic strategy for patients with a completely resected IIA-IIIA non-small cell lung cancer (NSCLC). Regarding the moderate benefit of AC and the lack of literature on AC use in real-life practice, we aimed to evaluate compliance to guidelines, AC safety and efficacy in a less selected population. Methods: Between January 2009 and December 2014, we retrospectively analysed 210 patients with theoretical indication of AC following curative-intent lung surgery for a completely resected IIA-IIIA NSCLC. The primary objective of this retrospective study was to evaluate compliance to AC guidelines. Secondary objectives included safety and efficacy of AC in real-life practice. Results: Among 210 patients with a theoretical indication of AC, chemotherapy administration was validated in multidisciplinary team (MDT) for 62.4% of them and 117 patients (55.7%) finally received AC. Patient's clinical conditions were the main reasons advanced in MDT for no respect to AC guidelines. Most of the patients received cisplatin-vinorelbine (86.3%) and AC was initiated within 8 weeks following lung surgery for 73.5% of patients. One-half of patients who received AC experienced side effects leading to either dose-intensity modification or treatment interruption. In real-life practice, AC was found to provide a survival benefit over surgery alone. Factors related to daily-life practice such as delayed AC initiation or incomplete AC planned dose received were not associated with an inferior survival. Conclusions: Although AC use might differ from guidelines in real-life practice, this retrospective study highlights that AC can be used safely and remains efficient among a less selected population. In the context of immunotherapy and targeted therapies development in peri-operative treatment strategies, the place of AC has to be precised in the future.

Use of adjuvant chemotherapy in resected non-small cell lung cancer in real-life practice: a systematic review of literature.

BACKGROUND: Adjuvant chemotherapy (AC) is recommended since 2004 for patients with a completely resected non-small cell lung cancer (NSCLC). Indeed, several randomized clinical trials have demonstrated an improved survival for patients treated with adjuvant cisplatin-based regimen than surgery alone. In these large clinical trials, patients were well selected and fit to receive AC. As the benefit of AC was estimated at 5.4% of 5-year overall survival (OS), it seems important to evaluate AC use in a less selected population. In particular, elderly patients were underrepresented in large randomized clinical trials. Furthermore, other confounding factors might limit AC efficacy in real-life practice such as the delay of chemotherapy initiation following lung surgery or the number of AC cycles received. Therefore, the aim of this systematic review is to summarize the state of the literature on AC use in current clinical practice. METHODS: A systematic assessment of literature articles and reviews on AC use in real-life practice was performed by searching in several relevant database including Medline, Google Scholar and Cochrane Library following PICOS (i.e., Population, Intervention, Comparison, Outcomes, Study design) eligibility criteria and PRISMA guidelines. Among the 1,957 results obtained with the request formulated on these research database, 56 relevant articles on AC use in non-trial setting were selected and included in the results section. RESULTS: This systematic literature review highlights the lack of literature on AC use in real-life practice as most of these studies were retrospective. Interestingly, a delayed AC-mostly due to postoperative complications-was better than surgery alone. Furthermore, AC was less purposed to elderly patients, despite retrospective studies outlined that this therapeutic option could be benefit in this specific population as for younger patients. In real-life practice, AC was also often incomplete due to adverse events, but dose reduction or omission was not always associated with an inferior survival. In non-trial setting, number of AC cycles delivered, dose reduction or omission is quite similar to randomized clinical trials. DISCUSSION: Nowadays, AC is part of the therapeutic strategy used in completely resected NSCLC. In a population of less selected patients, this systematic literature review shows that AC can be used safely and efficiently, especially in elderly patients. As well, delayed AC seems effective. Finally, the place of immunotherapy and targeted therapies have to be precised in the future as well as biomarkers to better select patients that would response to chemotherapy.

Histopathological typing in diffuse malignant epithelioid mesothelioma: implication for prognosis and molecular basis.

The prognostic impact of tumour grading, cytological and architectural patterns and stromal features in diffuse pleural malignant epithelioid mesothelioma (MEM) has been partly studied but not correlated to molecular features. We performed a retrospective study on 92 MEM in our department in order to assess the prognostic role of architectural and stromal patterns, especially tumour to stroma ratio. Secondly, based on The Cancer Genome Atlas (TCGA) database, we analysed the differentially expressed genes in prognostic groups of interest. Our results showed that tumour grading, tumour to stroma ratio and predominant pattern were related to overall survival, p≤0.001, p=0.01 and p=0.001, respectively. In univariate analysis, for high grade tumours hazard ratio (HR) was 4.75 (2.47-9.16), for stroma poor tumours HR=0.016, for predominant tubular or tubulopapillary pattern HR=0.044. In multivariate analysis, high grade tumours were related to overall survival [HR=3.09 (1.50-6.35), p=0.002] and predominant tubular or tubulopapillary pattern [HR=0.56 (0.32-0.99), p=0.045]. In TCGA analysis, after grading of diagnostic slides, we showed that KRTDAP and CXRCR1 expression was higher in low grade tumours, unlike PDZD7 and GPR176 expression which was higher in high grade tumours. FAM81B had a higher expression in stroma poor tumours. We did not find any differentially expressed genes in the architectural patterns group. Our work suggests that tumour grading is an important parameter in MEM with an underlying genomic basis. The role of tumour to stroma ratio needs to be investigated and might also have a genomic basis.

Heterogeneity of PD-L1 expression in lung adenocarcinoma metastasis is related to histopathological subtypes.

OBJECTIVES: The heterogeneity of PD-L1 expression and its relationship with histopathological subtype has recently been shown on primary tumor but has not been evaluated on metastases. The aim of our work is to analyze PD-L1 expression within each histopathological pattern on resected metastases. MATERIAL AND METHODS: 136 patients were included in this retrospective study. Immunohistochemistry was performed with 22C3 laboratory-developed test. The Tumor Proportion Score was evaluated on each subtype. RESULTS: The most frequent major histopathological subtype was solid (n = 69, 50.7 %), followed by acinar (n = 37, 27.2 %), micropapillary (n = 14, 10.3 %) and papillary (n = 10, 7.3 %). Mean percentage of PD-L1 expression for each subtype was at 28+/-4.8 % for solid subtype, 5.3+/-1.9 % for acinar subtype, 5+/-1.9 % for papillary subtype and 23.6+/-4.1 % for micropapillary subtype. Mean percentage of PD-L1 expression was different between solid pattern and acinar pattern (p < 0.001), solid pattern and papillary pattern (p = 0.007), micropapillary pattern and acinar pattern (p < 0.001) and micropapillary pattern and papillary pattern (p = 0.015). CONCLUSION: To conclude, we have showed firstly that several patterns are present in metastases of lung adenocarcinoma, secondly that the evaluation of patterns and PD-L1 stain on different patterns is reproducible, thirdly that pattern heterogeneity is related to PD-L1 staining, fourthly that in metastatic lung adenocarcinoma with at least two patterns, solid and micropapillary subtypes have higher levels of PD-L staining, fifthly that PD-L1 heterogeneity between different patterns is not a rare event. These results might explain discrepancies of PD-L1 results between biopsies and surgical samples and the fact that some patients might respond to checkpoint inhibitors even though PD-L1 expression is low or absent.

[Thoracic splenosis mimicking pleural and pulmonary metastasis]. / Splénose thoracique mimant une atteinte pleuropulmonaire métastatique.

Splenosis corresponds to an autotransplantation of splenic tissue, consecutive to a traumatic or surgical wound of the spleen. The peritoneal cavity is usually affected but intrathoracic nodules are also described, when simultaneous rupture of the spleen and diaphragmatic laceration exist. Diaphragmatic laceration may be subclinical. Lesions are generally asymptomatic and are a fortuitous finding in radiographs or by the surgeons in the majority of the cases. We report a case of pleural and pulmonary splenosis, mimicking pleural and pulmonary metastasis of a dorsal melanoma.