Could PD-L1 positivity be associated with venous thrombosis in patients with non-small cell lung cancer?

The risk of venous thromboembolism (VTE) is increased in non-small cell lung cancer (NSCLC), and defining at-risk patients is important. Thus, we aimed to assess the association between programmed cell death ligand 1 (PD-L1) expression and VTE [pulmonary embolism (PE), deep venous thrombosis (DVT)] in NSCLC. In this retrospective, observational multicentre study, 369 patients with NSCLC who had PD-L1 immunohistochemistry based on biopsies taken between January 2017 and December 2019, were divided as PD-L1-positive (n = 181) and -negative (n = 188) groups, and low-positive (n = 99) and high-positive (n = 82) PD-L1 groups. Among all population, 12.5% of them developed a VTE during a median follow-up of 474 days. The rates of DVT, PE, and PE + DVT were 5.7%, 6% and 0.8%, respectively. VTE (15.5% vs. 9.5%) and DVT (3.8% vs. 7.4%) were similar between two groups, while PE was significantly higher in PD­L1-positive group than those in PD-L1-negative group (11.1% vs 1%, p < 0.001). There were no significant differences between low- and high-positive groups in terms of VTE (14.1% vs. 17%), PE (12.1% vs. 9.8%), and DVT (2% vs. 6.1%). In the multivariate analysis, multiple metastases (Hazard ratio [HR] 4.02; 95% confidence interval [Cl] 1.18-13.63; p = 0.07) and PD-L1 positivity was associated with an increased PE risk (HR 8.39; 95% Cl 2.07-34.07; p = 0.003). In conclusion, PD-L1 positivity may be of important role in predicting the increased risk of PE in patients with NSCLC and thereby may be used to define patients likely to benefit from thromboprophylaxis.

Importance of Histopathological Grading for Treatment Selection in Malignant Mesothelioma.

BACKGROUND: Complexities in TNM staging in epithelioid malignant pleural mesothelioma (MPM) may lead to errors in treatment selection, leading to major surgical interventions in patients with low survival expectations. METHODS: Sixty-nine stage I epithelioid MPM patients, including 27 patients treated with pleurectomy/decortication (P/D) and multimodal therapy (MMT) (the P/D [MMT] group), and 42 patients treated with chemotherapy or chemoradiotherapy (the CRT group), were included in the study. After an initial evaluation of overall survival, all patients were grouped in terms of histopathological parameters and treatment types, and then, a secondary survival evaluation was performed for the groups. RESULTS: Forty-one patients were male, the mean age was 61.8 years. The median survival time was 26 months in the P/D (MMT) group, and 19.6 months in the CRT group, but the difference was not statistically significant. After grouping according to pathological criteria, a median survival time of 32.4 ± 2.9 months in the P/D (MMT) group and 21.9 ± 3.2 months in the CRT group was obtained among patients with histopathological low-grade tumors. Among patients with high-grade tumors, the median survival time was 18.3 ± 2.6 months in the P/D (MMT) group and 17 ± 4.4 months in the CRT group. Among patients with low-grade tumors, the P/D (MMT) group had longer survival. Median survival times were similar among patients with high-grade tumors. CONCLUSION: In epithelioid MPM, histopathological grading by video-assisted thoracic surgery pleural biopsy can prove accurate in selecting patients for P/D and MMT.

High grade tumor budding is associated with poor survival in pathologic stage I lung adenocarcinoma.

AIM: Tumor budding is a significant prognostic parameter that has been related to aggressive behavior in early-stage tumors of various origins. The aim of this study was to evaluate the clinicopathological significance of tumor budding in pathologic stage (pStage) I lung adenocarcinomas. METHODS: This study comprised 107 patients who underwent curative resection for pStage I lung adenocarcinomas at our hospital between December 2010 and January 2016. We examined tumor budding on routine hematoxylin and eosin (H&E) slides from resected specimens. Tumors were categorized into two groups based on the degree of tumor budding: low grade (grade 0-1) and high grade (grade 2-3). We evaluated the relationship between tumor budding and overall survival (OS), disease-free survival (DFS) and clinicopathological parameters. RESULTS: There is a significant difference (p = 0.002) between the 5-year DFS rates of the high-grade and the low-grade tumor budding group, which were 70 % and 90 %, respectively. High-grade tumor budding positive patients from the same pathological stage (p < 0.001; HR = 2.93 [1.51-5.68]) and clinical stage (p = 0.002) had poorer cumulative survival rates than low grade tumor budding positive patients. High grade tumor budding was positively associated with spread through air spaces (STAS) (p < 0 0.001), lymphovascular invasion (LVI) (p < 0.001), tumor necrosis (p < 0.001), high SUVmax value (SUVmax>3.0) (p < 0.001), and tumor size >20 mm (p = 0.024). High-grade tumor budding was significant prognostic factor of OS (p < 0.006) and DFS (p < 0.001) on univariate Cox regression hazard model analysis. However, it did not show significance in the multivariate analysis (p > 0.05). CONCLUSIONS: High-grade tumor budding is an independent prognostic factor and associated with adverse clinicopathological features and poor survival rates. We proposed that high-grade tumor budding should be recognized as a new prognostic parameter and will be beneficial in predicting the clinical course in pStage I lung adenocarcinomas.

Small cell lung cancer stem cells display mesenchymal properties and exploit immune checkpoint pathways in activated cytotoxic T lymphocytes.

Small cell lung cancer (SCLC) is an aggressive tumor type with early dissemination and distant metastasis capacity. Even though optimal chemotherapy responses are observed initially in many patients, therapy resistance is almost inevitable. Accordingly, SCLC has been regarded as an archetype for cancer stem cell (CSC) dynamics. To determine the immune-modulatory influence of CSC in SCLC, this study focused on the characterization of CD44+CD90+ CSC-like subpopulations in SCLC. These cells displayed mesenchymal properties, differentiated into different lineages and further contributed to CD8+ cytotoxic T lymphocytes (CTL) responses. The interaction between CD44+CD90+ CSC-like cells and T cells led to the upregulation of checkpoint molecules PD-1, CTLA-4, TIM-3, and LAG3. In the patient-derived lymph nodes, CD44+ SCLC metastases were also observed with T cells expressing PD-1, TIM-3, or LAG3. Proliferation and IFN-γ expression capacity of TIM-3 and LAG3 co-expressing CTLs are adversely affected over long-time co-culture with CD44+CD90+ CSC-like cells. Moreover, especially through IFN-γ secreted by the T cells, the CSC-like SCLC cells highly expressed PD-L1 and PD-L2. Upon a second encounter with immune-experienced, IFN-γ-stimulated CSC-like SCLC cells, both cytotoxic and proliferation capacities of T cells were hampered. In conclusion, our data provide evidence for the superior potential of the SCLC cells with stem-like and mesenchymal properties to gain immune regulatory capacities and cope with cytotoxic T cell responses. With their high metastatic and immune-modulatory assets, the CSC subpopulation in SCLC may serve as a preferential target for checkpoint blockade immunotherapy .

Pulmonary vascular alterations in explanted lung after transplantation.

Widespread pulmonary destruction and fibrosis can be seen in end-stage pulmonary diseases. This situation causes vascular remodeling of the pulmonary circulation and pulmonary hypertension. Lung transplantation is an alternative treatment for end-stage pulmonary diseases. The purpose of this study is to research pathological vascular alterations retrospectively in explanted lungs with or without pulmonary hypertension. 57 explanted lungs were evaluated for occlusive intimal fibroelastosis, smooth muscle proliferation, medial hypertrophy, intimal cellular or fibrous thickening, hemosiderosis, plexiform lesion, angiomatoid lesion, arteriosclerosis, venopathy, capillary duplication and arteriovenous malformation. Both systolic and mean pulmonary artery pressures were defined. The relationship between vascular patterns and pulmonary hypertension was investigated. Pathological vascular alterations in explanted lungs with or without pulmonary hyper- tension included medial hypertrophy (80.71%), intimal cellular or fibrous thickening (80.7%), arteriosclerosis (77.19%), smooth muscle proliferation (55.3%) and arteriovenous malformation (50.3%). Hemosiderosis (12.5%), plexiform lesion (14%) and venopathy (21%) were less frequent pathological vascular alterations. Capillary duplication was common in secondary pulmonary hypertension and was statistically meaningful. Although medial hypertrophy and intimal thickness were seen in pulmonary hypertension, they can also be observed in end-stage pulmonary diseases without pulmonary hypertension. Interstitial capillary duplication was an important histopathological finding in end-stage lung diseases with pulmonary arterial hypertension.

Mediastinal ectopic thyroid diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration: Report of three cases.

An ectopic thyroid gland results from the abnormal migration of the thyroid in the course of its development. Primary ectopic mediastinal thyroid is very rare and occurs in less than 1% of all goiters that can be surgically excised. Ectopic thyroid tissue has a characteristic sonographic appearance as smooth-bordered, homogeneous, hypoechoic tissue with fine specular echoes. We report 3 cases of mediastinal ectopic thyroid diagnosed by endobronchial ultrasound-guided transbrochial needle aspiration biopsy.

How many samples would be optimal for endobronchial cryobiopsy?

BACKGROUND: Cryobiopsy, which provides larger specimens without crush artifact, is a good option for the diagnosis of visible endobronchial tumors. While there are several papers on diagnostic performance, application protocols vary between centers. In this study, we aimed to find the optimal number of cryobiopsies in endobronchial tumors. METHODS: We prospectively involved cases with a visible endobronchial tumor in which conventional diagnostic measures failed and/or a therapeutic interventional bronchoscopy was planned. Endobronchial tumor was visualized, and four cryobiopsies were taken with a dedicated flexible probe. The samples were evaluated by a pathologist who was blinded to the order of the biopsies. The cumulative performances of one to four cryobiopsies were compared, and a complication analysis was conducted. RESULTS: A total of 50 patients were involved. Four cryobiopsies were taken from 49 patients, and a single biopsy was taken from one case. The sensitivities of one, two, three and four biopsies were 82, 93.9, 93.9 and 95.9 %, respectively. The difference in performance of one and two biopsies was significant (p = 0.031), but the third and fourth biopsies were found to be unnecessary (p = 1.0 for second versus third and p = 1.0 for second versus fourth). Bleeding risk increased when ≥3 cryobiopsies were taken (Odds Ratio 2.758). CONCLUSIONS: When the diagnostic benefits and complication rates were considered, two cryobiopsies were found to be optimal for endobronchial tumors. In patients with non-diagnostic conventional bronchoscopy, endobronchial tumors may be diagnosed by cryobiopsy.

Can Sericin Prove Useful as a Pleurodesis Agent or Tissue Glue?

Background Sericin is a natural, gum-like, macromolecule protein, synthesized from silkworms for the formation of cocoon shells. The aim of the present study is to describe the effects of sericin when used for pleurodesis and/or as tissue glue. Methods Adult, male, 12-week-old Wistar albino rats, weighing 257 to 395 g were used in the present study (n = 12). The animals were randomly divided into two equal groups as the sericin and the control group. After intramuscular administration of the anesthetic agent, the rats were intubated and mechanically ventilated. A left thoracotomy was performed and 30 mg sericin powder was instilled into the thoraxes of the sericin group. The remaining rats were allocated to a sham thoracotomy group. The animals were housed in individual cages, fed ad-libitum, and sacrificed 8 days after. After sacrifice, the left hemithoraxes were removed en bloc and underwent histopathologic examination. Results Masson trichrome staining was applied on the visceral pleura sections of all the animals. Each animal specimen (n = 6, 100%) in the control group showed minimal collagen deposition, while only one rat (16.67%) in the sericin group had minimal collagen deposition. However, in the sericin group, five animals (83.33%) showed dense collagen deposition, fibroblastic activity, and fibrosis. According to the test method, independent t-test, developing fibroblastic activity and fibrosis are statistically significant between the two groups (p < 0.01). There were no foreign-body reactions and no evidence of biological glue on the specimens in the sericin group. The rats in the sericin group had lower inflammatory reactions compared with those in the control group. Emphysema was observed in two rats (33.33%) in the sericin group and in four rats (66.67%) in the control group. Therefore, sericin was found to be associated with an increase in fibroblastic activity and fibrosis in visceral pleura without exerting any adverse effect on the lung parenchyma. Conclusion Sericin is a new and researchable protein for chest diseases and thoracic surgery. To develop an effect of dense collagen deposition, fibroblastic activity, and fibrosis in the visceral pleura, without significant adverse effects, is remarkable. Therefore, sericin may be useful as a pleurodesis agent or natural biological glue in the future. Sericin treatment can add value to the disciplines of pulmonology and thoracic surgery.

Retrospective evaluation of patients with organizing pneumonia: is cryptogenic organizing pneumonia different from secondary organizing pneumonia?

INTRODUCTION: Organizing pneumonia (OP) is an uncommon clinic opathological situation among lung diseases. If no underlying cause can be detected, it is named as cryptogenic OP (COP). In this study, the etiologic and clinical characteristics of patients diagnosed as OP in our hospital in the last ten years were evaluated retrospectively. It was also aimed to make a comparison between COP and secondary OP patients. MATERIALS AND METHODS: One hundred sixty-five patients diagnosed as OP pathologically in the 10 year period from August 2003 to August 2013 were included into that study. Patients' data were evaluated retrospectively from the medical records. RESULT: One hundred sixty five patients pathologically diagnosed as OP were included. Diagnostic methods were trans-thoracic fine-needle biopsy (TTFNB) in 89 (53.9%) patients, open lung biopsy (lobectomy, wedge resection, segmentectomy) in 52 (31.5%) patients and transbronchial biyopsy (TBB) in 24 (14.5%) patients. One hundred (60.6%) of the patients were defined as COP and 65 (39.4%) as secondary OP. Cough, fatigue and dyspnea were the most common symptoms on admission. We detected OP cases secondary to anthracosis and cyst hydatic besides other well known etiologies. In 61 patients, the main radiologic manifestation was multiple bilateral patchy consolidation typical for OP. In 76 patients focal lesions (solid mass, cavitating mass lesion) and in 6 patients infiltrative opacities were detected radiologically. CONCLUSIONS: There is no difference between properties of OP from clinical, laboratory and radiologic finding sin the criptogenic and seconder form of OP. Although it is not asserted, cyst hidatic and anthracosis could be kept in mind for the list of underlying ethiologies for secondary OP.

EGFR, KRAS, and BRAF mutational profiles of female patients with micropapillary predominant invasive lung adenocarcinoma

Background/aim: This study aimed to analyze EGFR, KRAS, and BRAF mutations in females with micropapillary predominant invasive lung adenocarcinoma and their relationships with immunohistochemical and clinicopathological patterns.Materials and methods: A total of 15 females with micropapillary lung adenocarcinoma were selected. Mutational analysis of the EGFR, KRAS, and BRAF genes was carried out. Information regarding the demographic data, tumor size, treatment, and survival time for each patient was collated, and the predominant cell type, secondary architectural growth patterns, psammoma bodies, necrosis, and visceral pleural and angiolymphatic invasions were evaluated.Results: We identified EGFR mutation in six cases, KRAS mutation in three cases, and BRAF mutation in one case. EGFR, c-kit, VEGFR, and bcl-2 positivity was observed in ten, seven, four, and six cases, respectively. All cases were positive for VEGF (strong positivity in 11 cases and weak positivity in four cases) and bcl-2 (strong positivity in nine cases and weak positivity in six cases). Seven (46.6%) cases were positive for c-kit and 10 (66.6%) cases were positive for EGFR. Conclusion: EGFR mutation occurred at a higher incidence rate in micropapillary predominant invasive adenocarcinoma than has previously been found in conventional lung adenocarcinomas. KRAS mutation was observed as having a similar frequency to what was previously observed, but the frequency of BRAF mutation was lower than previously reported.

ß-HCG secretion by a non-small cell lung cancer: a case report.

Paraneoplastic secretion of beta human chorionic gonadotropin (ß-HCG) in non-small cell lung cancer (NSCLC) has been rarely reported. A 43-year old male patient was admitted with dyspnea and chest pain. Thorax computed tomography (CT) revealed bilateral multiple masses and pleural effusion at right hemithorax. Positron emission tomography (PET)-CT showed pathologic 18 FDG uptake at mass lesions and mediastinal lymph nodes. The serum ß-HCG level was elevated. A bronchoscopy was performed and endobronchial lesion was observed. Since a definitive diagnosis was not achieved by pathologic examination of biopsy specimen, bronchoscopy was repeated and a sample was taken by cryobiopsy. The pathologic examination revealed non-small cell lung cancer.In conclusion, the case was presented because of extremely rare occurence of NSCLC secreting ß-HCG.

Autologous anti-SOX2 antibody responses reflect intensity but not frequency of antigen expression in small cell lung cancer.

BACKGROUND: Anti-SOX2 antibody responses are observed in about 10 to 20% of small cell lung cancer (SCLC) patients. The aim of this study was to determine whether such responses reflect a particular pattern of SOX2 protein expression in the tumor and whether this pattern associates with clinical outcome. METHODS: Paraffin embedded tumor tissues, obtained from SCLC patients who had no evidence of paraneoplastic autoimmune degeneration, were evaluated for SOX2 expression by immunohistochemistry for both intensity and extent of staining. Sera from the same patients were tested for autologous antibodies against recombinant SOX2 by enzyme-linked immunosorbent assay (ELISA). Correlates between overall survival and various clinical parameters including SOX2 staining and serology were determined. RESULTS: SOX2 protein expression was observed in tumor tissue in 89% of patients. Seventeen patients (29%) were seropositive for SOX2 antibodies and, in contrast to SOX2 staining, the presence of antibody correlated with limited disease stage (p = 0.05). SOX2 seropositivity showed a significant association with the intensity of SOX2 staining in the tumor (p = 0.02) but not with the frequency of SOX2 expressing cells. CONCLUSION: Anti-SOX2 antibodies associate with better prognosis (limited stage disease) while SOX2 protein expression does not; similar to reports from some earlier studies. Our data provides an explanation for this seemingly contrasting data for the first time as SOX2 antibodies can be observed in patients whose tumors contain relatively few but strongly staining cells, thus supporting the possible presence of active immune-surveillance and immune-editing targeting SOX2 protein in this tumor type.

Intrathoracic neurogenic tumors.

BACKGROUND: Intrathoracic neurogenic tumors are uncommon neoplasms arising from nerve tissues. This study reports on our 24-year single-center experience with intrathoracic neurogenic tumors. PATIENTS AND METHODS: We retrospectively analyzed the postoperative pathological records of 19,378 operations performed in our clinic between January 1988 and December 2011 and included cases with diagnosis of neurogenic tumors. RESULTS: The study included 149 patients (90 females and 59 males) with an average age of 24.5 years (7 months to 77 years). The study group comprised 29 infants and children, and 120 adults. Of the patients, 72 had benign schwannomas, 10 malignant schwannomas, 17 neurofibromas, 24 ganglioneuromas, 9 ganglioneuroblastomas, 4 neuroblastomas, 9 primitive neuroectodermal tumors, and 4 paragangliomas. Concerning the location of these lesions, 131 were located in the posterior mediastinum, 8 in the lung parenchyma, 5 in the chest wall, 3 in the anterior mediastinum, and 2 in the thoracic inlet. The majority of nerve cell tumors were in infants and children (79.3%), whereas the nerve sheath tumors most commonly occurred in adults (78.3%). There were 117 benign and 32 malignant tumors across all age groups. The rate of malignancy was 41.4% in infants and children, compared with 16.7% in adults. Symptoms were seen in 65% of the adult patients and 79.3% of the infant and children patients. Seven tumors were associated with von Recklinghausen's disease. In six patients (4.0%), the tumor showed an intraspinal extension. Surgical resection of the tumor was complete in 142 of 149 patients (95.3%). CONCLUSION: The treatment of choice for malignant and benign thoracic neurogenic tumors is complete resection. The objective of resection is to avoid local invasion, facilitate differential histopathological diagnosis to determine other treatment options, and to prevent malignant degeneration.

Intrathoracic fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva is an extremely rare disease that is usually seen in the form of sporadic cases and seems to be localized outside of the thoracic cavity. Inflammation and trauma are accused in the etiology, and too many diagnostic mistakes are done. The disease, which may present genetic transmission and has not a definitive treatment, was seen as an intrathoracic mass for the first time. Intrathoracic mass was excised, and the cure was achieved in our patient, who was defined to be sporadic as a result of familial screening.

Role of orthopedia homebox protein in subclassification of pulmonary carcinoid tumors: Retrospective analysis of 110 cases.

Background: Orthopedia homeobox protein (OTP), highlighted as a sensitive and specific marker for pulmonary carcinoids, may provide a more objective criterion for subclassification. Materials and Methods: A total of 110 patients who underwent surgery for pulmonary carcinoids (2009-2019) were included. Gender, age, application complaint, tumor diameter and location, typical and atypical tumor type, lymph node involvement, stage, recurrence, and survival data were evaluated retrospectively with OTP nuclear staining. Results: The sensitivity of OTP was 66.4%. OTP in subclassifying pulmonary carcinoids was not significant. There was no significant relationship between OTP and lymph node involvement, recurrence, and survival. Conclusion: OTP does not provide significant results in the subclassification of typical and atypical carcinoid tumors and the evaluation of recurrence and survival of carcinoid tumor cases.

Does cryptogenic organizing pneumonia change seasonal?

BACKGROUND AND AIM: Meteorological factors affect the respiratory system, and the most important factor is the change in ambient temperature and humidity. We aimed to investigate the seasonal characteristics of patients diagnosed with cryptogenic organizing pneumonia. METHODS: The study included 84 cryptogenic organizing pneumonia, 55 chronic obstructive pulmonary disease, and 42 asthma patients. To determine the characteristics of the disease according to the seasons, the number of attacks and admissions was grouped according to the seasonal characteristics and analyzed for three groups. RESULTS: Among cryptogenic organizing pneumonia and chronic obstructive pulmonary disease patients, males significantly predominated (p<0.001). The hospitalization rate was highest in chronic obstructive pulmonary disease patients but similar to cryptogenic organizing pneumonia and asthma patients (p<0.001). The highest admission rate in cryptogenic organizing pneumonia patients was observed in spring (39.3% in spring, 26.2% in fall, 22.6% in winter, and 11.9% in summer). In winter, cryptogenic organizing pneumonia patients were admitted less frequently than chronic obstructive pulmonary disease and asthma patients. The neutrophil-to-lymphocyte ratio was higher in cryptogenic organizing pneumonia patients than in asthma patients and similar to chronic obstructive pulmonary disease patients. CONCLUSION: As a result of our study, the high rate of diagnosis and admission in the spring in cryptogenic organizing pneumonia suggested that the effect of allergens on the formation of cryptogenic organizing pneumonia should be investigated. In contrast, it should be kept in mind that cryptogenic organizing pneumonia may develop as a prolonged finding of involvement that may occur in the lung parenchyma due to lung infections and/or cold weather triggering during the winter months. In this regard, further studies can be conducted in which allergens and/or the history of infection in patients and meteorological variables are also evaluated.

An Unusual Diagnosis in a Single-Lung Transplant Recipient: Secondary Amyloidosis.

Silicosis, a progressive, fibrotic occupational lung disease with no known treatment, is an uncommon indication for lung transplant. There is a paucity of research on patients with silicosis who have received lung transplants. The long-term consequences of the native lung in patients with severe chronic silicosis who have had a single-lung transplant are also of interest. We present a case of amyloidosis in a patient who underwent a single-lung transplant for silicosis.

Rapidly Progressive Pulmonary Kaposi Sarcoma After Bilateral Sequential Lung Transplant: A Case Report.

Skin cancers are among the rarely seen complications after solid-organ transplant. Kaposi sarcoma invasion to an allograft is an uncommon condition. In this study, we present a case of Kaposi sarcoma in a 58-year-old patient diagnosed at 8 months after bilateral sequential lung transplant due to chronic obstructive pulmonary disease. Kaposi sarcoma showed rapid progression despite immunosuppressive drug modification, resulting in lung involvement and respiratory failure. Rapid and complete improvement was achieved with rapid diagnosis and aggressive treatment that included combined chemotherapy after surgery. The patient presented with no complications from Kaposi sarcoma at month 26 after transplant.

Single versus multiple video-assisted thoracocopic lung biopsy for suspected interstitial lung disease: a perspective on diagnostic efficacy and length of hospital stay.

Background: Nearly one-third of the patients with interstitial lung disease (ILD) require surgical biopsy for a definite diagnosis. Video-assisted thoracoscopic surgical (VATS) biopsy has replaced open lung biopsy, but the number of biopsy required to achieve an accurate diagnose is controversial. Objectives: Our study aims to show that a well-planned single VATS biopsy is as effective as multiple biopsies for the accurate diagnosis of ILD by reduced days of hospital stay. Methods: We included 111 patients with suspected ILD who underwent VATS biopsy in our study. Patients were separated into three groups according to the number of biopsies obtained. The differences between groups for diagnostic yield, mean time for chest tube removal, perioperative complications, and approximate volume per biopsy were analyzed statistically. Results: Eighteen single, 74 double, and 19 triple biopsies were made. Mean times of chest tube removal and hospital stay for single, double, and triple biopsy were 3.5, 4.8, and 6.1 days respectively. The number of biopsy and length of hospital stay was strongly related (p = 0.02), but there was no difference for diagnostic yield between single and multiple biopsy groups (p > 0.05). There was no intraoperative complication or perioperative mortality. In postoperative period, eight patients with multiple biopsies had prolonged air leak. Conclusion: Although classical knowledge suggests multiple biopsies from different locations of the lung are essential, recent reports have shown that the site and the number of biopsy are not as effective as previously thought in achieving the diagnosis for ILD. Our results show that a "single" biopsy, decided with multidisciplinary evaluation, is an effective and safe diagnostic tool, with lesser days of hospital stay. Main novel aspects: 1. The classical knowledge that multiple biopsies should be taken from different regions of the lung in the diagnosis of interstitial lung diseases has changed over time.2. Diagnostic concordance between multiple biopsy specimens is above 85%.3. A "single" biopsy, decided with multidisciplinary evaluation, is an effective and safe diagnostic tool with lower days of hospital stay.