Association of PET/CT and VATS findings with histology analysis in the study of pleural effusions.

INTRODUCTION: Histological analysis of the pleura obtained by video-assisted thoracoscopic surgery (VATS) is the best diagnostic technique in the study of neoplastic pleural effusions. This study evaluates the relationship between Positron Emission Tomography (PET)/Computed Tomography (CT) and VATS findings, the result of the first pleural biopsy, and the final diagnosis of malignancy or non-malignancy. METHODS: Prospective study of consecutive patients with pleural effusions undergoing PET/CT and VATS from October 2013 to December 2023. The following variables were recorded: PET/CT score (nodular pleural thickening, pleural nodules with standardized uptake value (SUV) > 7.5, lung mass or extra pleural malignancy, mammary lymph node with SUV > 4.5 and cardiomegaly); VATS data (drained volume, visceral and parietal pleural thickening, nodules or masses, septa, plaques, fluid appearance, trapped lung, and suspected diagnosis of the procedure), as well as the histological study of the first pleural biopsy (benign or malignant) and the final diagnosis of benign or malignant pleural effusion. A logistic regression study of the variables was performed. RESULTS: 95.8% of the patients with PET/CT and pleuroscopy not suggestive of malignancy had non-malignant histological findings, while 93.2% of the patients with PET/CT and pleuroscopy suggestive of malignancy had malignant histological findings. PET/CT, pleuroscopy, and the result of the first pleural biopsy showed a significant association with the final diagnosis of pleural effusion. CONCLUSIONS: There is a strong association between PET/CT findings, VATS and pleural histology.

Diagnóstico y evolución de los pacientes con derrames pleurales idiopáticos / Diagnosis and outcome of patients with idiopathic pleural effusions

Introducción No se ha determinado la evolución de los pacientes con derrames pleurales idiopáticos con un seguimiento a largo plazo. Métodos Entre octubre de 2013 y junio de 2021 se hizo un seguimiento prospectivo de todos los pacientes con derrame idiopático mediante exploración clínica y estudios de imagen al cabo de 1, 3 y seis meses y cada seis meses durante un mínimo de un año. Resultados Veintinueve pacientes fueron diagnosticados de derrame idiopático y objeto de seguimiento. Durante el seguimiento se detectó un mesotelioma en dos pacientes al cabo de siete y 18 meses; en uno de ellos se observó líquido pleural teñido de sangre y el otro refirió una pérdida de peso de 10%. En ninguno de los pacientes con derrame que cubriera menos de dos tercios del hemitórax y sin síntomas constitucionales ni aparición de líquido teñido de sangre se diagnosticó un mesotelioma. La mayoría de los derrames desaparecieron o mostraron una clara mejoría en los primeros seis meses. Conclusiones Los pacientes sin pérdida de peso y con derrames no hemáticos pequeños pueden beneficiarse de un tratamiento conservador y un seguimiento clínico-radiológico (AU)

Introduction Long-term follow-up course for patients with idiopathic pleural effusions has not been established. Methods From October 2013 to June 2021 all patients with idiopathic effusion were prospectively followed up with clinical examination and imaging at 1,3,6 and every 6 months for a minimum of 1 year. Results Twenty-nine patients were diagnosed with idiopathic effusion and followed up. Mesothelioma was detected during the follow-up in two patients at 7 and 18 months, one of whom had blood-tinged pleural fluid and the other reported a 10% weight loss. Mesothelioma was not diagnosed in any of the patients with effusion covering less than two thirds of the hemithorax, and without constitutional symptoms or a blood-tinged fluid appearance. Most of the effusions resolved or showed a clear improvement in the first six months. Conclusions Patients without weight loss and with small, non-hematic effusions, may benefit from conservative treatment and clinical-radiological follow-up (AU)

Diagnosis and outcome of patients with idiopathic pleural effusions.

INTRODUCTION: Long-term follow-up course for patients with idiopathic pleural effusions has not been established. METHODS: From October 2013 to June 2021 all patients with idiopathic effusion were prospectively followed up with clinical examination and imaging at 1, 3, 6 and every 6 months for a minimum of 1 year. RESULTS: Twenty-nine patients were diagnosed with idiopathic effusion and followed up. Mesothelioma was detected during the follow-up in two patients at 7 and 18 months, one of whom had blood-tinged pleural fluid and the other reported a 10% weight loss. Mesothelioma was not diagnosed in any of the patients with effusion covering less than two thirds of the hemithorax, and without constitutional symptoms or a blood-tinged fluid appearance. Most of the effusions resolved or showed a clear improvement in the first six months. CONCLUSION: Patients without weight loss and with small, non-hematic effusions, may benefit from conservative treatment and clinical-radiological follow-up.

Analysis of mismatch repair (MMR) proteins expression in a series of malignant pleural mesothelioma (MPM) patients.

BACKGROUND: Promising results have been reported with immune checkpoint inhibitors (ICI) in a small proportion of MPM patients. MMR deficiency (dMMR) has been well described in several malignancies and was approved as a biomarker for anti-PD-1 inhibitors. Next generation sequencing (NGS) data demonstrated that 2% of MPM harbor microsatellite instability. The aim of this study is to characterize MMR by immunohistochemistry (IHC) in a series of MPM including a subset of patients treated with immunotherapy. METHODS: Tumors of 159 MPM p diagnosed between 2002 and 2017 were reviewed. Formalin-fixed, paraffin-embedded tissue was stained for MLH1, MSH2, MSH6 and PMS2 and tumors were classified as dMMR (MMR protein expression negative) and MMR intact (all MMR proteins positively expressed). We retrospectively collected clinical outcomes under standard chemotherapy and experimental immunotherapy in the entire cohort. RESULTS: MMR protein expression was analyzed in 158 samples with enough tissue and was positive in all of the cases. Twenty two patients received ICI with anti-CTLA4 or anti-PD-1 blockade in clinical trials, 58% had a response or stable disease for more than 6 m, with median progression-free survival (PFS) of 5.7 m (2.1-26.1 m). The median overall survival (mOS) in all population was 15 months (m) (13.5-18.8 m). In a multivariable model factors associated to improved mOS were PS 0, neutrophil-lymphocyte ratio (NLR) < 5 and epithelioid histology (p < 0.001). CONCLUSIONS: In our series we were unable to identify any MPM patient with dMMR by IHC. Further studies are needed to elucidate potential predictive biomarkers of ICI benefit in MPM.

Analysis of different levels of positive end-expiratory pressure during lung retrieval for transplantation: an experimental study.

Atelectasis and inadequate oxygenation in lung donors is a common problem during the retrieval of these organs. Nevertheless, the use of high positive end-expiratory pressure (PEEP) is not habitual during procedures of lung retrieval. Twenty-one Sprague-Dawley male consanguineous rats were used in the study. The animals were divided into 3 groups according to the level of PEEP used: low (2 cmH2O), moderate (5 cmH2O), and high (10 cmH2O). Animals were ventilated with a tidal volume of 6 mL/kg. Before lung removal, the lungs were inspected for the presence of atelectasis. When atelectasis was detected, alveolar recruitment maneuvers were performed. Blood gasometric analysis was performed immediately. Finally, the lungs were retrieved, weighed, and submitted to histological analysis. The animals submitted to higher PEEP showed higher levels of oxygenation with the same tidal volumes PO2=262.14 (PEEP 2), 382.4 (PEEP 5), and 477.0 (PEEP 10). The occurrence of atelectasis was rare in animals with a PEEP of 10 cmH2O, which therefore required less frequent recruitment maneuvers (need for recruitment: PEEP 2=100%, PEEP 5 =100%, and PEEP 10=14.3%). There was no change in hemodynamic stability, occurrence of pulmonary edema, or other histological injuries with the use of high PEEP. The use of high PEEP (10 cmH2O) was feasible and probably a beneficial strategy for the prevention of atelectasis and the optimization of oxygenation during lung retrieval. Clinical studies should be performed to confirm this hypothesis.

Analysis of different levels of positive end-expiratory pressure during lung retrieval for transplantation: an experimental study

Atelectasis and inadequate oxygenation in lung donors is a common problem during the retrieval of these organs. Nevertheless, the use of high positive end-expiratory pressure (PEEP) is not habitual during procedures of lung retrieval. Twenty-one Sprague-Dawley male consanguineous rats were used in the study. The animals were divided into 3 groups according to the level of PEEP used: low (2 cmH2O), moderate (5 cmH2O), and high (10 cmH2O). Animals were ventilated with a tidal volume of 6 mL/kg. Before lung removal, the lungs were inspected for the presence of atelectasis. When atelectasis was detected, alveolar recruitment maneuvers were performed. Blood gasometric analysis was performed immediately. Finally, the lungs were retrieved, weighed, and submitted to histological analysis. The animals submitted to higher PEEP showed higher levels of oxygenation with the same tidal volumes PO2=262.14 (PEEP 2), 382.4 (PEEP 5), and 477.0 (PEEP 10). The occurrence of atelectasis was rare in animals with a PEEP of 10 cmH2O, which therefore required less frequent recruitment maneuvers (need for recruitment: PEEP 2=100%, PEEP 5 =100%, and PEEP 10=14.3%). There was no change in hemodynamic stability, occurrence of pulmonary edema, or other histological injuries with the use of high PEEP. The use of high PEEP (10 cmH2O) was feasible and probably a beneficial strategy for the prevention of atelectasis and the optimization of oxygenation during lung retrieval. Clinical studies should be performed to confirm this hypothesis.

Diagnóstico por imagen de rotura espontánea de quiste mediastínico del conducto torácico / Diagnostic imaging in spontaneous rupture of a thoracic duct cyst in the mediastinum

Los quistes mediastínicos del conducto torácico son extremadamente raros y pueden dar lugar a quilotórax por rotura espontánea o en el postoperatorio de estas lesiones. Se presenta el caso de una mujer de edad adulta con un quiste mediastínico del conducto torácico y quilotórax debido a rotura espontánea, no descrito previamente en la bibliografía de forma específica. Los hallazgos clínico-radiológicos, el manejo terapéutico y la anatomía patológica se describen, revisando la bibliografía respecto a esta entidad (AU)

Thoracic duct cysts in the mediastinum are extremely rare; they can give rise to chylothorax when they spontaneously rupture or after they are operated on. We present the case of an adult woman with a thoracic duct cyst in the mediastinum and chylothorax from its spontaneous rupture; to our knowledge, this phenomenon has not been specifically reported before. We describe the clinical and radiological findings, the therapeutic management, and the pathology findings, reviewing the literature for this entity (AU)

Analysis of expression of PTEN/PI3K pathway and programmed cell death ligand 1 (PD-L1) in malignant pleural mesothelioma (MPM).

BACKGROUND: Malignant pleural mesothelioma (MPM) frequently express elevated AKT/mTOR activity. Previous reports in gliomas, colon, breast and prostate cancer suggest that PTEN/PI3K pathway may be important for the induction of PD-L1 expression. This study explored the expression of PTEN/PI3K pathway and PD-L1 in MPM and its relationship with the patient́s prognosis MATERIAL AND METHODS: Twenty seven consecutive MPM patients were reviewed. Formalin-fixed, paraffin-embedded tissue biopsies were used for immunohistochemical analysis of PTEN/PI3K pathway and PD-L1 RESULTS: Expression of PTEN, mTOR, pAKT, p4EBP1, peif4E, pS6 and FOXO3a was found in 88.5%, 92.3%, 78.3%, 38.5%, 100%, 52.2% and 100% of tumors and PD-L1 in 23%. We found a significant correlation between pAKT, FOXO3a and PD-L1 expression and longer overall survival (p <0.05). We did not identify significant association between the level of PD-L1 expression and alterations in PI3K pathway CONCLUSIONS: This study shows PTEN/PI3K pathway and PD-L1 in MPM are frequently activated. Our results suggests that there is not association between PD-L1 and the involvement of the PI3K pathway in MPM.

Diagnostic imaging in spontaneous rupture of a thoracic duct cyst in the mediastinum. / Diagnóstico por imagen de rotura espontánea de quiste mediastínico del conducto torácico.

Thoracic duct cysts in the mediastinum are extremely rare; they can give rise to chylothorax when they spontaneously rupture or after they are operated on. We present the case of an adult woman with a thoracic duct cyst in the mediastinum and chylothorax from its spontaneous rupture; to our knowledge, this phenomenon has not been specifically reported before. We describe the clinical and radiological findings, the therapeutic management, and the pathology findings, reviewing the literature for this entity.

Prediction of non-sentinel lymph node metastasis in early breast cancer by assessing total tumoral load in the sentinel lymph node by molecular assay.

INTRODUCTION: The one-step nucleic acid amplification (OSNA) is a molecular procedure that yields a semiquantitative result for detection of nodal metastasis. Size of metastasis in the sentinel lymph node (SLN) by conventional histology has been described as a predictive factor for additional axillary metastasis. The objective of this study is to quantify intraoperatively the total tumoral load (TTL) in the positive SLNs assessed by OSNA and to determine whether this TTL predicts non-SLN metastasis in patients with clinically node negative early stage breast cancer. METHODS: 306 patients with cT1-3N0 invasive breast cancer who had undergone intraoperative SLN evaluation by OSNA were included. TTL was defined as the addition of CK19 mRNA copies of each positive SLN (copies/µL). RESULTS: TTL was a predictive factor of additional non-SLN metastasis in the complete axillary lymph node dissection (cALND) (OR, 1.67; 95% CI, 1.18-2.35). In the multivariate analysis, the TTL was a predictor of non-SLN metastasis in HR positive patients (OR, 1.69; 95% CI, 1.19-2.41). In our cohort of patients, with a TTL ≤1.2 × 10(5) copies/µL, there was a specificity of 85.3% and negative predictive value (NPV) of 80%. If we consider only the HR positive patients, with a TTL ≤5 × 10(5) copies/µL there was a specificity of 86.7% and NPV of 83.7%. CONCLUSIONS: TTL assessed by OSNA assay predicts for additional non-SLN metastasis and this intraoperative tool can help guiding decisions on performing a cALND in breast cancer patients.