Multidisciplinary Approach to the Diagnosis of Idiopathic Interstitial Pneumonias: Focus on the Pathologist's Key Role

Idiopathic Interstitial Pneumonias (IIPs) are a heterogeneous group of the broader category of Interstitial Lung Diseases (ILDs), pathologically characterized by the distortion of lung parenchyma by interstitial inflammation and/or fibrosis. The American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary consensus classification of the IIPs was published in 2002 and then updated in 2013, with the authors emphasizing the need for a multidisciplinary approach to the diagnosis of IIPs. The histological evaluation of IIPs is challenging, and different types of IIPs are classically associated with specific histopathological patterns. However, morphological overlaps can be observed, and the same histopathological features can be seen in totally different clinical settings. Therefore, the pathologist's aim is to recognize the pathologic-morphologic pattern of disease in this clinical setting, and only after multi-disciplinary evaluation, if there is concordance between clinical and radiological findings, a definitive diagnosis of specific IIP can be established, allowing the optimal clinical-therapeutic management of the patient.

PKDN: Prior Knowledge Distillation Network for bronchoscopy diagnosis

Bronchoscopy plays a crucial role in diagnosing and treating lung diseases. The deep learning-based diagnostic system for bronchoscopic images can assist physicians in accurately and efficiently diagnosing lung diseases, enabling patients to undergo timely pathological examinations and receive appropriate treatment. However, the existing diagnostic methods overlook the utilization of prior knowledge of medical images, and the limited feature extraction capability hinders precise focus on lesion regions, consequently affecting the overall diagnostic effectiveness. To address these challenges, this paper proposes a prior knowledge distillation network (PKDN) for identifying lung diseases through bronchoscopic images. The proposed method extracts color and edge features from lesion images using the prior knowledge guidance module, and subsequently enhances spatial and channel features by employing the dynamic spatial attention module and gated channel attention module, respectively. Finally, the extracted features undergo refinement and self-regulation through feature distillation. Furthermore, decoupled distillation is implemented to balance the importance of target and non-target class distillation, thereby enhancing the diagnostic performance of the network. The effectiveness of the proposed method is validated on the bronchoscopic dataset provided by Harbin Medical University Cancer Hospital, which consists of 2,029 bronchoscopic images from 200 patients. Experimental results demonstrate that the proposed method achieves an accuracy of 94.78% and an AUC of 98.17%, outperforming other methods significantly in diagnostic performance. These results indicate that the computer-aided diagnostic system based on PKDN provides satisfactory accuracy in diagnosing lung diseases during bronchoscopy.

Pediatric Pulmonology 2022 year in review: Rare and diffuse lung disease

The field of rare and diffuse pediatric lung disease continues to evolve and expand rapidly as clinicians and researchers make advancements in the diagnosis and treatment of children's interstitial and diffuse lung disease, non-cystic fibrosis bronchiectasis, and primary ciliary dyskinesia. Papers published on these topics in Pediatric Pulmonology and other journals in 2022 describe newly recognized disorders, elucidate disease mechanisms and courses, explore potential biomarkers, and assess novel treatments. In this review, we will discuss these important advancements and place them in the context of existing literature.

Utility of Transbronchial Cryobiopsy via Flexible Bronchoscope in Diagnosis of Isolated Pulmonary LCH: A Case Report

Flexible bronchoscopes are increasingly being used in diagnostic and therapeutic medicine and have obviated the need for and risks associated with general anesthesia. Here the authors present the case of a 2-y-old girl who was diagnosed with isolated pulmonary Langerhans cell histiocytosis by histopathology; a lung biopsy sample was obtained using a cryoprobe via a flexible bronchoscope. The girl was brought in with complaints of loss of weight, appetite loss, and rapid breathing for the past 2 mo. Examination revealed hypoxia, tachypnea, clubbing with failure to thrive, and bilateral crepitations on auscultation. Imaging studies showed ground-glass opacities with multiple cystic lesions in both lungs. A preliminary diagnosis of LCH was made, and transbronchial cryobiopsy was done via a flexible bronchoscope. Histopathology confirmed the diagnosis with Cluster of differentiation 1a (CD1a) staining. A flexible bronchoscope can be a useful tool for obtaining lung biopsy samples using a cryoprobe in children.

The Evolving Concept of the Multidisciplinary Approach in the Diagnosis and Management of Interstitial Lung Diseases

BACKGROUND

Interstitial lung diseases (ILDs) are a group of heterogeneous diseases characterized by inflammation and/or fibrosis of the lung interstitium, leading to a wide range of clinical manifestations and outcomes. Over the years, the literature has demonstrated the increased diagnostic accuracy and confidence associated with a multidisciplinary approach (MDA) in assessing diseases involving lung parenchyma. This approach was recently emphasized by the latest guidelines from the American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and Latin American Thoracic Association for the diagnosis of ILDs.

METHODS

In this review, we will discuss the role, composition, and timing of multidisciplinary diagnosis (MDD) concerning idiopathic pulmonary fibrosis, connective tissue disease associated with ILDs, hypersensitive pneumonia, and idiopathic pneumonia with autoimmune features, based on the latest recommendations for their diagnosis.

RESULTS

The integration of clinical, radiological, histopathological, and, often, serological data is crucial in the early identification and management of ILDs, improving patient outcomes. Based on the recent endorsement of transbronchial cryo-biopsy in idiopathic pulmonary fibrosis guidelines, an MDA helps guide the choice of the sampling technique, obtaining the maximum diagnostic performance, and avoiding the execution of more invasive procedures such as a surgical lung biopsy. A multidisciplinary team should include pulmonologists, radiologists, pathologists, and, often, rheumatologists, being assembled regularly to achieve a consensus diagnosis and to review cases in light of new features.

CONCLUSIONS

The literature highlighted that an MDA is essential to improve the accuracy and reliability of ILD diagnosis, allowing for the early optimization of therapy and reducing the need for invasive procedures. The multidisciplinary diagnosis of ILDs is an ongoing and dynamic process, often referred to as a "working diagnosis", involving the progressive integration and re-evaluation of clinical, radiological, and histological features.

Diagnosis of diffuse parenchymal lung diseases using transbronchial cryobiopsy guided by endobronchial ultrasound compared to clinicoradiological diagnosis

BACKGROUND

This study aimed to evaluate the safety and effect of transbronchial cryobiopsy guided by radial probe endobronchial ultrasound (RP-EBUS) compared with clinicoradiological diagnoses in diffuse parenchymal lung diseases (DPLDs).

METHODS

A total of 60 patients with DPLDs confirmed by chest computed tomography (CT) who underwent transbronchial lung cryobiopsy guided by RP-EBUS were enrolled. The ultrasound images were obtained and identified together with corresponding chest CT characteristics. The cryobiopsy samples were evaluated histopathologically and compared with CT imaging, and the complications were analyzed.

RESULTS

The multidisciplinary diagnosis was clear in 51 (85%) participants but unclear in the remaining 9 (15%) participants. In transbronchial cryobiopsy guided by RP-EBUS, 36 (60%) participants had the biopsy in 1 lobe while 24 (40%) had a biopsy in 2 different lobes, with a mean biopsy specimen size of 43.17±15.25 mm². The histopathologic diagnosis based on biopsy confirmed the preprocedural clinicoradiological diagnosis in 51 (85%) patients and clarified the diagnosis in the other 9 patients with unclear clinicoradiological diagnosis, including alveolated lung parenchyma with interstitial chronic inflammation in 4 (6.7%) cases and chronic bronchiolitis and interstitial lymphocytic infiltrates in the other 5 (8.3%). Intraprocedural complications occurred in 57 (95%) patients, including pneumothorax in 9 (15%), bleeding in 47 (78.3%), and hypoxemia in 1 (1.7%). The ultrasound images of DPLDs were normal, mesh (n=24), nodular (n=9), and alveolar type (n=27).

CONCLUSIONS

Transbronchial cryobiopsy guided by RP-EBUS is safe and effective and can supply additional information to the clinicoradiological approach for correct diagnosis of DPLDs.

Evaluation of Transbronchial Lung Cryobiopsy Freezing Time, Biopsy Size, Histological Quality, and Incidence of Complication: A Prospective Clinical Trial

BACKGROUND

Transbronchial cryobiopsy (TBCB), a novel way of obtaining a specimen of lung tissue using a flexible cryoprobe, can obtain large lung biopsies without crush artifacts. The freezing time of TBCB was empirically selected from 3 to 7 s in the previous studies. However, no consensus has yet been reached regarding the optimal freezing time used in TBCB.

OBJECTIVES

The primary endpoint was biopsy size in different freezing times. The secondary endpoints included sample histological quality, diagnostic confidence, and complications in different freezing times.

METHODS

Patients who were suspected of DPLD requiring histopathological examination for further evaluation were enrolled in this study. Distinct biopsies were obtained by using different freezing times increased from 3 to 6 s sequentially. Samples were reviewed by 2 external expert pathologists.

RESULTS

A total of 33 patients were enrolled, and 143 transbronchial cryobiopsies were taken in this trial. An average of 4.33 samples were taken from each patient. The mean biopsy size of different freezing times from 3 to 6 s was 9.10 ± 4.37, 13.23 ± 5.83, 16.26 ± 5.67, and 18.83 ± 7.50 mm2, respectively. A strong correlation between freezing time and biopsy size was observed (r = 0.99, p < 0.01). Statistically significant difference of biopsy size was detected in the freezing time of 3 s versus 4 s (p < 0.01) and 4 s versus 5 s (p = 0.02), but not in the freezing time of 5 s versus 6 s (p = 0.10). Overall bleeding in different freezing times from 3 to 6 s was 53.33%, 67.50%, 89.47%, and 77.14%, respectively. A significantly higher overall bleeding was observed when the freezing time exceeded 4 s (RR = 1.67, p < 0.01). Pneumothorax occurred in 4 cases (12.12%). One lethal case (3.03%) was noted 25 days after TBCB. Lung parenchyma was preserved well in all cryobiopsy samples. Thirty-one (93.94%) patients' histopathological findings were identified as sufficient to establish a CRP diagnosis. There was no statistical difference in diagnostic confidence between different freezing times.

CONCLUSION

A longer freezing time was associated with a larger size of the biopsy sample but a higher risk of bleeding. The optimal transbronchial cryobiopsy freezing time is 3-4 s, which is easily achievable and provides an adequate biopsy size whilst creating a safety threshold from complications.

Transbronchial Lung Cryobiopsy in children

BACKGROUND

Transbronchial Lung Cryobiopsy (TBLC) is a novel technique, available globally only in a limited number of centers. Since the data on the role of TBLCs amongst pediatric patients is limited, the aim was to evaluate its efficacy in diagnosing lung diseases amongst children.

METHODS

The records of 28 pediatric patients were retrospectively reviewed from October 2016 till September 2018. The participants' demographic information, procedural indications, sample adequacy, diagnostic utility, and the complications associated with this type of bronchoscopy apparatus were further assessed.

RESULTS

Twenty-eight pediatric patients aged 22 months to 17 years underwent TBLC. From the 73 obtained biopsies, 97% had an adequate sampling size. The diagnostic yield of this method was 92.8%. The most common complication was mild bleeding. Transient hypoxemia and bronchospasm were observed in eleven and eight patients, respectively. Furthermore, most of them (78.6%) had uneventful post-procedure and recovery.

CONCLUSIONS

TBLC was a relatively safe and effective method with high accuracy and fewer complications in diagnosing and monitoring lung diseases in the selected children. However, more extensive multicentre trials are warranted to corroborate the potential benefits of this novel technique.

Combination of the Archimedes Navigation System and cryobiopsy in diagnosis of diffuse lung disease

OBJECTIVE

To evaluate the efficacy of the Archimedes Navigation System (Broncus Medical, San Jose, CA, USA) for guidance during transbronchial cryobiopsy and the incidence of complications in patients with diffuse lung disease.

METHODS

High-resolution computed tomography and transbronchial cryobiopsy were used to evaluate eight patients with diffuse lung disease. The Archimedes Navigation System was used before cryobiopsy to obtain the best path with which to avoid large vessels. Three to five cryobiopsy specimens were taken from each sampled segment.

RESULTS

Preoperative planning using the Archimedes Navigation System was successfully performed on all eight patients. The probe-to-pleura distance was approximately 10 mm. No cases of pneumothorax occurred, one patient developed moderate bleeding, two developed minor bleeding, and five developed minimal bleeding that stopped spontaneously. A final diagnosis was obtained for seven patients, and ongoing follow-up was being conducted for the last patient at the time of this writing.

CONCLUSIONS

This is the first report of combining navigation technology with cryobiopsy to diagnose diffuse lung disease. The Archimedes Navigation System, which provides real-time guidance, is helpful in pre-cryobiopsy planning and diagnosis of diffuse lung disease. Moreover, this system can reduce the pneumothorax rate and bleeding risk by avoiding large vessels.

Diagnostic yield and safety of bronchofiberscopy for pulmonary alveolar proteinosis

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a diffuse lung disease characterized by the abnormal accumulation of surfactant-like material within the alveolar spaces and distal bronchioles. If high-resolution computed tomography (HRCT) indicates the presence of PAP, a definitive diagnosis of PAP is established when consistent pathological findings are obtained. Herein, we retrospectively studied the yield and safety of bronchofiberscopy in the diagnosis of PAP.

METHODS

One hundred and fifty consecutive patients with PAP were prospectively registered in the PAP cohort database of the National Hospital Organization Kinki-Chuo Chest Medical Center between January 1991 and December 2018. We examined 86 patients who underwent bronchofiberscopy with bronchoalveolar lavage (BAL) and transbronchial lung forceps biopsy (TBLB).

RESULTS

The patients included 56 men and 30 women, with a median age of 57 years. All patients had autoimmune PAP, and the median level of anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies was 42.8 μg/mL. The diagnostic yield was 90.7% (78/86) with BAL and 81.4% (70/86) with TBLB. The combination of BAL and TBLB increased the yield to 98.8%. Age, disease severity score, and frequency of traction bronchiectasis on HRCT were significantly different between the TBLB-positive and TBLB-negative groups. No patient developed serious complications due to bronchofiberscopy; TBLB-related complications included pneumothorax (3.5%) and minimal bleeding (7.0%).

CONCLUSIONS

Bronchofiberscopy, in combination with BAL and TBLB, is an effective and safe method for the diagnosis of PAP, with a yield of 98.8%.

Cryobiopsy in Lung Cancer Diagnosis-A Literature Review

Optimizing the diagnosis of lung cancer represents a challenge, as well as a necessity, for improving the low survival of these patients. Flexible bronchoscopy with forceps biopsy is one of the key diagnostic procedures used for lung tumors. The small sample size and crush artifacts are several factors that can often limit access to a complete diagnosis, therefore leading to the need of repeating the bronchoscopy procedure or other invasive diagnostic methods. The bronchoscopic cryobiopsy is a recent technique that proved its utility in the diagnosis of both endobronchial and peripheral lung tumors. In comparison with conventional forceps biopsy, studies report a higher diagnostic yield and a superior quality of the collected samples for both the histopathological and the molecular diagnosis of lung cancer. This method shows promising results in sampling lung tissue, alone, or in conjunction with fluoroscopy or radial endobronchial ultrasound (r-EBUS). With a good safety and cost-benefit profile, this novel method has the potential to improve the diagnosis, and therefore the management of lung cancer patients. The objective of this narrative review is to provide a comprehensive review of the recent data regarding the advantages of cryobiopsy and r-EBUS in lung cancer diagnosis.

Implementation of transbronchial lung cryobiopsy in a tertiary referral center for interstitial lung diseases: a cohort study on diagnostic yield, complications, and learning curves

Background

Transbronchial lung cryobiopsy (TBLC) has been introduced as an alternative to surgical lung biopsy (SLB) in the diagnostics of interstitial lung diseases (ILD). Despite controversy on safety, TBLC is increasingly implemented in ILD centers with an apparent diagnostic yield comparable to SLB. The aim of this study was to assess TBLC implementation experiences from a tertiary Danish ILD center regarding diagnosis, complications, and learning curves for TBLC performance.

Methods

TBLC was prospectively performed in a cohort of patients with unclassifiable ILD based on a preceding multidisciplinary clinical and radiological revision. TBLC was performed as an outpatient procedure with the patients in general anesthesia using a flexible bronchoscope with 1.9 or 2.4 mm cryoprobes. Learning curves for TBLC performance were calculated using cumulated sum (CUSUM) scores for diagnostic yield, pneumothorax, and bleeding.

Results

From February 2017 to March 2020 141 patients (86 (61%) men, median age 69 years [IQR, 60–74 years]) had TBLC performed. A histological and confirmative diagnosis was made in 101 patients (75.2%) and 124 patients (87.9%, i.e. clinical diagnostic yield), respectively, in whom idiopathic interstitial pneumonias constituted the majority (67.3%) of the clinical diagnoses. We observed 2 deaths (1.4%) within 30 days of TBLC, but no procedure-related mortality or severe bleeding. Moderate bleeding occurred in 23 patients (16.3%), pneumothorax in 21 patients (14.9%) with only 14 patients (9.9%) requiring a pleural drain. Based on the CUSUM score analysis, the diagnostic yield obtained was satisfactory throughout the period.

Conclusion

This study reports experiences of outpatient TBLC implementation in a tertiary referral ILD center from the largest investigated TBLC cohort in Scandinavia The diagnostic yield and prevalence of complications obtained by TBLC from this single center study on unclassifiable ILD support outpatient TBLC as a valuable and safe alternative to SLB to diagnose ILD in well-selected patients. The learning curves for TBLC were acceptable in the hands of experienced bronchoscopists.

Transbronchial Cryobiopsy in Interstitial Lung Diseases: State-of-the-Art Review for the Interventional Pulmonologist

Interstitial lung diseases are a heterogenous group of disorders that are often difficult to diagnose precisely. Clinical, laboratory, radiographic, and histologic information may be needed to arrive at the correct diagnosis. The multidisciplinary discussion has been proven to be useful in this patient group. Transbronchial cryobiopsy has become a popular method for obtaining tissue samples. Over the course of the last decade, there has been a significant amount of research assessing the feasibility, safety, and diagnostic endpoints of transbronchial cryobiopsy in patients with interstitial lung disease. Data continues to mount to support its use, which has been reflected in guidelines and expert panel reports. Patient selection, procedural performance, and appropriate specimen handling are critical factors for success. A coordinated approach by pulmonologists with expertise in interstitial lung diseases, interventional pulmonologists, and thoracic pathologists is essential. In this evidence-based narrative review, we address transbronchial cryobiopsies from these three distinct perspectives. In addition, the current literature was used to address nine common procedural questions.

Endobronchial ultrasound guided transbronchial cryobiopsy versus forceps biopsy in peripheral lung lesions

INTRODUCTION

Radial probe endobronchial ultrasound (RP-EBUS) is a modern technique for diagnosis of peripheral lung lesions. It is assumed that the addition of transbronchial cryobiopsy (TBCB) could increase the diagnostic value for RP-EBUS.

OBJECTIVES

The main objectives were to evaluate the efficacy and safety of RP-EBUS-guided TBCB for diagnosis of peripheral lung lesions and comparing it with RP-EBUS-guided transbronchial forceps biopsy.

METHODS

Sixty patients with peripheral lung diseases were divided into two groups. Group I included 45 patients who were eligible for TBCB and they subjected to forceps transbronchial biopsy (forceps TBB) and TBCB guided by RP-EBUS. Fifteen patients who were not eligible for TBCB were included in group II and they were subjected to forceps TBB and/or cytology retrieval procedures guided by RP-EBUS.

RESULTS

In group I, forceps TBB had sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of; 67.5%, 100%, 100%, 18.8%, and 69.8%, respectively, while TBCB had sensitivity, specificity, PPV, NPV, and accuracy of 75%, 100%, 100%, 23.1%, and 76.7%, respectively. The sensitivity in group II was 80% and the overall results including both groups were sensitivity, specificity, PPV, NPV, and accuracy of 85.2%, 100%, 100%, 42.8%, and 86.7%, respectively. Regarding the complications, only one patient (1.7%) had significant bleeding. One patient (1.7%) had pneumothorax and another patient (1.7%) suffered from hypoxemia.

CONCLUSIONS

RP-EBUS-guided TBCB is a safe and effective technique for diagnosis of peripheral lung lesions. TBCB has achieved higher diagnostic values and better quality of samples.

Usefulness and safety of transbronchial biopsy with large forceps during flexible bronchoscopy

Transbronchial lung biopsy (TBLB) using forceps is one of the most common procedures used to obtain lung tissue. The procedure's usefulness remains limited when diagnosing interstitial lung diseases. This retrospective descriptive study analyzed the feasibility and safety of using large forceps for TBLB in all patients who underwent TBLB from 2014 to 2018 for diffuse lung disease where the diagnosis could not be made by high-resolution chest computed tomography. We excluded patients with radiographic features of usual interstitial pneumonia. Among the 35 study patients, 7 were men and 28 were women. Diagnoses included respiratory associated bronchiolitis (7), diffuse alveolar damage (4), organizing pneumonia (4), nonspecific interstitial pneumonitis (3), acute fibrinous organizing pneumonia (3), sarcoidosis (2), hypersensitivity pneumonitis (2), IgG4 interstitial lung disease (1), eosinophilic pneumonia (1), pulmonary alveolar proteinosis (1), pulmonary fibrosis (1), pneumocystis (1), plasma-rich bronchiolitis (1), and diffuse alveolar hemorrhage (1). In three cases, the biopsies were nondiagnostic. Two patients developed a pneumothorax, and one required chest tube placement. There was one episode of minor bleeding. No escalation of care or hospitalization was required. Large-forceps TBLB is a feasible and safe method for obtaining parenchymal lung biopsies.

Transbronchial cryobiopsy: an effective tool in the diagnosis of lymphoproliferative disorders of the lung

Introduction

Malignant lymphoproliferative disorders are rarely observed in the lung and, considering their clinical and radiological heterogeneity, diagnosis is often difficult and may require invasive methods. Transbronchial cryobiopsy has been confirmed as a new tool in the diagnosis of interstitial lung diseases, given its fewer risks and costs compared to surgical approach. This study is aimed at assessing the effectiveness of cryobiopsy in the diagnosis of lymphoproliferative disorders.

Materials and methods

Among 970 consecutive cryobiopsies, performed between January 2011 and June 2018 at Morgagni Hospital of Forlì, Italy, 13 cases of lymphoproliferative disorders were collected.

Results

In 12 out of 13 cases a precise pathological diagnosis could be reached with the support of immunohistochemistry (IHC) and molecular ancillary studies. In the only case in which cryobiopsy did not lead to a definitive diagnosis, the subsequent surgical biopsy also did not help to clarify the diagnosis. Severe bleeding or pneumothorax did not occur in any case. On average, five biopsies were obtained per case, with a mean total area of 1161 mm², and only 5 out of 65 specimens were inadequate for diagnosis. Instant freezing did not produce tissue artefacts nor did it affect IHC and molecular tests. In all cases the amount of available tissue was sufficient for all ancillary studies.

Conclusions

Transbronchial lung cryobiopsy is safe and effective for diagnosis in patients with suspected pulmonary involvement by lymphoproliferative disorders and it should therefore be considered a valid alternative to surgical biopsy in such cases.

Cryobiopsy is an effective method in the diagnosis of lymphoproliferative disorders. Transbronchial cryobiopsy allows immunohistochemical and molecular analysis. No severe bleeding or pneumothorax were observed in this study.https://bit.ly/2zdHPTn

Lung cryobiopsy and interstitial lung disease: What is its role in the era of multidisciplinary meetings and antifibrotics?

Diagnosing ILD can be complex, and despite detailed evaluation and HRCT imaging, many patients require lung biopsy to help classify their disease. SLB has served as the reference standard for histopathology in ILD, since initial classification schemes were created more than 50 years ago. Frequently, patients are too unwell to undertake SLB and remain unclassifiable, despite the input of expert MDD. This can limit access to therapy and establishment of prognosis. TBLC is an emerging procedure for sampling lung tissue with promising results in research and clinical settings. Although diagnostic yield is not as high as SLB, the risk profile looks to be more acceptable and the accuracy appears to be good. There is increasing evidence for the utility of cryobiopsy in ILD diagnosis, particularly within the MDD. Cryobiopsy serves as an important adjunct for the diagnosis of ILD, enhancing the diagnostic confidence of treating clinicians.

Role of Bronchoscopic Techniques in the Diagnosis of Thoracic Sarcoidosis

The diagnosis of sarcoidosis relies on clinical and radiological presentation, evidence of non-caseating granulomas in histopathology and exclusion of alternative causes of granulomatous inflammation. Currently, a proper diagnosis, with a high level of confidence, is considered as key to the appropriate diagnosis and management of the disease. In this sense, this review aims to provide a brief overview on the role of bronchoscopy in the diagnosis of thoracic sarcoidosis, incorporating newer techniques to establish, including endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), transesophageal ultrasound-guided needle aspiration with the use of an echo bronchoscope (EUS-B-FNA) and transbronchial lung cryobiopsy (TBLC). Most of the literature reports the diagnostic superiority of endosonographic techniques, such as EBUS-TBNA alone or in combination with EUS-FNA, over conventional bronchoscopic modalities in diagnosing Scadding stages I and II of the disease. Moreover, TBLC may be considered a useful and safe diagnostic tool for thoracic sarcoidosis, overcoming some limitations of transbronchial lung biopsy (TBLB), avoiding more invasive modalities and being complementary to endosonographic procedures such as EBUS-TBNA.

Cryoprobe biopsy for the diagnosis of acute hypoxemic respiratory failure of undetermined origin

Rationale

Acute hypoxemic respiratory failure is a condition that comprises a wide array of entities. Obtaining a histological lung sample might help reach a diagnosis and direct an appropriate treatment in a select group of patients.

Objective

To describe our experience in the use of cryobiopsy for the diagnosis of acute hypoxemic respiratory failure of undetermined origin.

Methods

Retrospective analysis of case series of patients with acute hypoxemic respiratory failure who underwent lung cryobiopsy at the Intensive Care Unit of the Hospital Italiano de Buenos Aires, Argentina.

Results

Cryobiopsy yielded a histological diagnosis in all patients (n = 10, 100%). This led to either a change in therapy or continuation of a specific treatment in eight of these patients. Cryobiopsy was found to be contributive in all the patients who did not meet Berlin criteria for acute respiratory distress syndrome. No major complications were associated with the procedure.

Conclusions

Cryobiopsy is a safe procedure with a high diagnostic yield in a selected group of patients.

Bronchoscopic Therapies for Peripheral Lung Malignancies

Current advances in guided bronchoscopy methods permit minimally invasive access to essentially any area of the lungs. This provides a potential means to treat patients with localized lung malignancies who might not otherwise tolerate conventional treatment, which commonly relies on surgical resection. Ablation methods have long been used for bronchoscopic treatment of central airway malignancies and percutaneous treatment of peripheral lung cancer. This article reviews ablation technologies being adapted for use with guided bronchoscopy and the current state of investigation for the treatment of peripheral lung malignancies.

Transbronchial Lung Cryobiopsy in the Diagnosis of Interstitial Lung Disease: A Retrospective Single-center Experience

BACKGROUND

Surgical lung biopsy (SLB) is the gold standard to aid diagnosis of interstitial lung disease (ILD). Complication rates are restrictive as routine approach for all patients with ILD. Transbronchial lung cryobiopsy (TBLC) is presumed to be a safe, less invasive alternative to assist multidisciplinary discussions regarding the diagnosis of ILD. Varying practice patterns and lack of consistent guidelines prohibit wide support of this technique. The purpose of this study was to evaluate safety and diagnostic yield of TBLC, with highlight of distinct technical features, in ILD.

METHODS

Retrospective study of patients with ILD on the basis of high-resolution chest computed tomography who underwent TBLC.

RESULTS

Of 121 TBLC, 40 patients (mean age, 57.2±13 y; 28 men) with ILD were referred for biopsy. Procedures were performed in endoscopy suite (60%) or operating room by using 1.9-mm cryoprobe. Biopsies were performed in 2 lobes with at least 3 to 5 specimens >5 mm in diameter. The average diameter and area of specimens were 5.7±2 mm and 40±2 mm, respectively. The most common diagnosis was nonspecific interstitial pneumonitis; usual interstitial pneumonia was diagnosed in 1 patient. Of 6 nondiagnostic specimens, 2 underwent SLB with subsequent diagnoses. Final histopathologic diagnostic rate was 85%. Bleeding was the most frequent complication.

CONCLUSION

We provided a detailed description of our TLBC technique and highlighted areas of similarity and differences among comparative studies and attest that TBLC is a safe alternative to SLB in the diagnosis of ILD. Our data also indicated the tendency for moderate-to-severe bleeding occurred more in the endoscopy suite.

Idiopathic pulmonary fibrosis: prognostic impact of histologic honeycombing in transbronchial lung cryobiopsy

Background

Prognostic evaluation in idiopathic pulmonary fibrosis (IPF) may be important as it can guide management decisions, but the potential role of honeycomb changes in providing information about outcome and survival of patients with IPF, particularly if diagnosed using cryobiopsy, has not been evaluated. Aim of this study was to determinate whether a relationship exists between honeycombing on cryobiopsy and clinical/radiological picture and outcome in patients with IPF and to assess whether the same pathologic criteria that have been used to define the UIP pattern (usual interstitial pneumonia) for surgical biopsy can also be applied to cryobiopsy.

Methods

Sixty-three subjects with a multidisciplinary diagnosis of IPF and a UIP pattern on cryobiopsy were evaluated. Patients were classified into two sub-groups depending on the presence of honeycombing on histology.

Results

The presence of honeycombing on cryobiopsy did not identify a specific phenotype of patients as it did not correlate with radiological and clinical picture and it was not associated neither with the risk of death (p = 0.1192) or with the event-free survival (p = 0.827); a higher number of samples and the presence of pleura on biopsy were instead associated with an increase in the finding of honeycombing.

Conclusions

The same pathologic criteria that have been used to define the UIP pattern in surgical biopsies (with honeycombing changes considered as non-mandatory for the definition of the pattern itself) can be applied to cryobiopsy samples, as the presence of these changes do not define different clinical or radiological phenotypes of patients with IPF.

Cavitary lung disease following transbronchial biopsy using cryoadhesion in a patient with diffuse parenchymal lung disease

Transbronchial lung biopsy using cryoadhesion is a diagnostic technique gaining in popularity. Several studies have been performed on its diagnostic yield and safety profile. However, definitive conclusions are limited due to the heterogeneity of results. The most common complications described in the current literature are pneumothorax and hemorrhage. This case describes a 60-year-old female who developed a cavitary lung lesion shortly after undergoing transbronchial lung cryobiopsy, highlighting the need for further research on the rarer complications that may be associated with this promising procedure.

Bronchoscopic mucosal cryobiopsies as a method for studying airway disease

BACKGROUND

Investigating disease mechanisms and treatment responses in obstructive airway diseases with invasive sampling are hampered by the small size and mechanical artefacts that conventional forceps biopsies suffer from. Endoscopic cryobiopsies are larger and more intact and are being increasingly used. However, the technique has not yet been explored for obtaining mucosa biopsies.

OBJECTIVE

To investigate differences in size and quality of endobronchial mucosal biopsies obtained with cryotechnique and forceps. Further, to check for eligibility of cryobiopsies to be evaluated with immunohistochemistry and in situ hybridization and to investigate tolerability and safety of the technique.

METHODS

Endobronchial mucosal biopsies were obtained with cryotechnique and forceps from patients with haemoptysis undergoing bronchoscopy and evaluated by quantitative morphometry, automated immunohistochemistry and in situ hybridization.

RESULTS

A total of 40 biopsies were obtained from 10 patients. Cross-sectional areas were threefold larger in cryobiopsies (median: 3.08 mm² (IQR: 1.79) vs 1.03 mm² (IQR: 1.10), P < 0.001). Stretches of intact epithelium were 8-fold longer (median: 4.61 mm (IQR: 4.50) vs 0.55 mm (IQR: 1.23), P = 0.001). Content of glands (median: 0.095 mm² (IQR: 0.30) vs 0.00 mm² (IQR: 0.01), P = 0.002) and airway smooth muscle (median: 0.25 mm² (IQR: 0.30) vs 0.060 mm² (IQR: 0.11), P = 0.02) was higher in the cryobiopsies compared with forceps biopsies. Further, the cryobiopsies had well-preserved protein antigens and mRNA. Mild to moderate bleeding was the only complication observed.

CONCLUSION AND CLINICAL RELEVANCE

By yielding significantly larger and more intact biopsies, the cryotechnique represents a valuable new research tool to explore the bronchi in airway disease. Ultimately with the potential to create better understanding of underlying disease mechanisms and improvement of treatments.

Optimize Transfer Learning for Lung Diseases in Bronchoscopy Using a New Concept: Sequential Fine-Tuning

Bronchoscopy inspection, as a follow-up procedure next to the radiological imaging, plays a key role in the diagnosis and treatment design for lung disease patients. When performing bronchoscopy, doctors have to make a decision immediately whether to perform a biopsy. Because biopsies may cause uncontrollable and life-threatening bleeding of the lung tissue, thus doctors need to be selective with biopsies. In this paper, to help doctors to be more selective on biopsies and provide a second opinion on diagnosis, we propose a computer-aided diagnosis (CAD) system for lung diseases, including cancers and tuberculosis (TB). Based on transfer learning (TL), we propose a novel TL method on the top of DenseNet: sequential fine-tuning (SFT). Compared with traditional fine-tuning (FT) methods, our method achieves the best performance. In a data set of recruited 81 normal cases, 76 TB cases and 277 lung cancer cases, SFT provided an overall accuracy of 82% while other traditional TL methods achieved an accuracy from 70% to 74%. The detection accuracy of SFT for cancers, TB, and normal cases are 87%, 54%, and 91%, respectively. This indicates that the CAD system has the potential to improve lung disease diagnosis accuracy in bronchoscopy and it may be used to be more selective with biopsies.

Novel application of cryobiopsy in the diagnosis of pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare disease diagnosed pathologically by the build up of surfactant in the alveolar spaces. Establishing a diagnosis usually requires invasive procedures such as bronchoalveolar lavage and forceps biopsy to obtain tissue specimens. Infrequently, surgery is required when histopathological results from other modalities are equivocal. Cryobiopsy has emerged as a novel technique for obtaining lung tissues in pulmonary diseases. Recently, cryobiopsy has been used to diagnose diffuse parenchymal lung disease, but it has rarely been used for the diagnosis of PAP. Here, we describe a 54-year-old male businessman presenting with intermittent coughing with yellowish sputum and dyspnoea upon exertion for half a year. Tissues from forceps biopsy fail to yield a specific diagnosis, whereas those from cryobiopsy confirm the diagnosis of PAP. Cryobiopsy offers several diagnostic advantages compared to conventional techniques and appears to be a potential diagnostic tool for diagnosing PAP.

Epidemiology of Rare Lung Diseases: The Challenges and Opportunities to Improve Research and Knowledge

Rare lung diseases encompass a broad spectrum of conditions and affect an estimated 1.2-2.5 million people in North America and 1.5-3 million people in Europe. While individual rare lung diseases affect less than 1 in 2000 individuals, collectively they have a significant impact upon the population at large. Hence it is vital to understand firstly the epidemiology and subsequently the pathogenesis and clinical course of these disorders. Through a greater understanding of these aspects of disease, progress can be made in reducing symptoms, containing healthcare costs and utilizing resources efficiently. Furthermore, a greater understanding of the pathobiology of rare lung diseases can inform both the pathogenesis and management of more common pulmonary disorders.In this chapter we review how epidemiological approaches and the utilization of patient registries has improved the knowledge and management of rare lung diseases. We further focus on the epidemiology of several of the more widely known rare pulmonary disorders, including idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF) and alpha-1 antitrypsin deficiency (AATD). To conclude we describe how patient advocacy groups and foundations have driven advances in research and management of ultra-rare lung diseases, namely, the major strides made in the management and understanding of lymphangioleiomyomatosis (LAM) and pulmonary alveolar proteinosis (PAP).We conclude that the models used to study some of the rarest of diseases may be successfully adopted by other rare and common disease communities, leading to improved care and the possibility of novel therapeutic options.

Acute Exacerbation of Interstitial Lung Disease After Cryobiopsy

Cryotherapy has been used in treatment of lung cancer for decades. The utility of cryotechnology in diagnosis of lung diseases is emerging and gaining popularity. Cryobiopsy (CB) of the lung, when compared with conventional transbronchial forceps lung biopsy, has proposed to have a higher diagnostic yield in interstitial lung disease by providing larger biopsy specimen and less crush artifact. Acute exacerbation of interstitial lung disease (AEILD) has been well described with surgical lung biopsies and, rarely, with conventional transbronchial forceps biopsy. The incidence of AEILD after CB is not known. Here we are presenting a case of AEILD after CB.

Dexmedetomidine plus sufentanil for pediatric flexible bronchoscopy: A retrospective clinical trial

Several studies have reported the use of dexmedetomidine (DEX) plus opioids for flexible bronchoscopy in both adults and children. To determine whether DEX plus sufentanil (SF) is safe for children, 142 children undergoing flexible bronchoscopy were assigned to one of three groups, each of which received the same SF loading dose and similar DEX and SF maintenance doses, but different loading doses of DEX: DS1 (DEX 0.5 μg·kg^–1), DS2 (DEX 1.0 μg·kg^–1), and DS3 (DEX 1.5 μg·kg^–1). The Ramsay sedation scale was maintained at 3 in all groups. Results showed that anesthesia onset time was shorter, and the perioperative hemodynamic profile was more stable, in the DS3 group. The number of intraoperative movements was also lowest in the DS3 group. The time to first dose of rescue midazolam and lidocaine was significantly longer, but the total corresponding accumulated doses were lower in the DS3 group. Although the time to recovery prior to discharge from the post anesthesia care unit was longer, the overall incidence of tachycardia was lower in the DS3 group, and it received the highest bronchoscopist satisfaction score among the three groups. We therefore conclude that high-dose DEX plus SF can be safely and efficaciously used in children undergoing flexible bronchoscopy.

Acute rejection

Despite induction immunosuppression and the use of aggressive maintenance immunosuppressive regimens, acute allograft rejection following lung transplantation is still a problem with important diagnostic and therapeutic challenges. As well as causing early graft loss and mortality, acute rejection also initiates the chronic alloimmune responses and airway-centred inflammation that predispose to bronchiolitis obliterans syndrome (BOS), also known as chronic lung allograft dysfunction (CLAD), which is a major source of morbidity and mortality after lung transplantation. Cellular responses to human leukocyte antigens (HLAs) on the allograft have traditionally been considered the main mechanism of acute rejection, but the influence of humoral immunity is increasingly recognised. As with other several other solid organ transplants, antibody-mediated rejection (AMR) is now a well-accepted and distinct clinical entity in lung transplantation. While acute cellular rejection (ACR) has defined histopathological criteria, transbronchial biopsy is less useful in AMR and its diagnosis is complicated by challenges in the measurement of antibodies directed against donor HLA, and a determination of their significance. Increasing awareness of the importance of non-HLA antigens further clouds this issue. Here, we review the pathophysiology, diagnosis, clinical presentation and treatment of ACR and AMR in lung transplantation, and discuss future potential biomarkers of both processes that may forward our understanding of these conditions.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia diagnosed by tranbronchoscopic cryoprobe biopsy technique

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) remains a poorly understood clinical entity. It is currently classified as a premalignant condition by the World Health Organization (WHO). Symptoms are similar to those associated with obstructive lung disease, including breathlessness and cough. The presentation is often initially ascribed to other diseases such as asthma or chronic obstructive pulmonary disease. Here, we present what we believe is the first described case of DIPNECH diagnosed by transbronchoscopic cryoprobe biopsy. The patient presented with chronic cough, dyspnoea, pulmonary function tests consistent with obstruction, and a computed tomography (CT) scan of chest with multiple nodules. The patient went on to have transbronchoscopic cryoprobe biopsies of the lung, which confirmed the diagnosis of DIPNECH.

Bilateral lung disease, extensive and diffuse. Diagnosis of pulmonary alveolar proteinosis by bronchoscopic cryobiopsy

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the intra-alveolar accumulation of a proteinaceous phospholipid-laden material called surfactant. Clinically, this disease should be suspected with respiratory failure in association with a crazy paving pattern on high-resolution chest computed tomography. We report a 24-year-old gentleman who was referred to us for a history of respiratory failure, treatment with invasive ventilation and tracheostomy. His blood exams and biochemistry were normal. His infectious and rheumatological panel was negative for a secondary disease. A flexible bronchoscopy with a transbronchial biopsy through a CryoProbe was performed. An anatomopathological analysis was periodic acid-Schiff positive for PAP. A CryoProbe is a recently developed diagnostic tool that improves the diagnostic yield in diffuse lung diseases compared to bronchoscopy with transbronchial biopsy. This method should be considered for patients with diffuse lung disease and PAP.

Multidisciplinary evaluation of interstitial lung diseases: current insights: Number 1 in the Series "Radiology" Edited by Nicola Sverzellati and Sujal Desai

Multidisciplinary team (MDT) diagnosis is regarded as the diagnostic reference standard for interstitial lung disease (ILD). Several studies have reported that MDT diagnosis is associated with higher levels of diagnostic confidence and better interobserver agreement when compared to the individual components of the MDT in isolation. Although this recommendation is widely accepted, no guideline statement specifies what constitutes an MDT meeting and how its participants should govern it. Furthermore, the precise role of an MDT meeting in the setting of ILD may vary from one group to another. For example, in some cases, the meeting will confine its discussion to characterising the disease and formulating diagnosis. In others, management decisions may also be part of the discussion. Surprisingly, there is no consensus on how MDT diagnosis is validated. As multidisciplinary evaluation contains all the available clinical information on an individual patient, there is no reference standard against which the veracity of MDT diagnosis can be tested. Finally, many of these uncertainties surrounding MDT meeting practice are unlikely to be answered by traditional evidence-based studies, which create difficulties when generating guideline recommendations. There is clearly a need for expert consensus on what constitutes acceptable MDT meeting practice. This consensus will need to be flexible to accommodate the variability in resources available to fledgling MDT groups and the variable nature of patients requiring discussion.

Diffuse parenchymal lung disease

Between September 2015 and August 2016 there were >1500 publications in the field of diffuse parenchymal lung diseases (DPLDs). For the Clinical Year in Review session at the European Respiratory Society Congress that was held in London, UK, in September 2016, we selected only five articles. This selection, made from the enormous number of published papers, does not include all the relevant studies that will significantly impact our knowledge in the field of DPLDs in the near future. This review article provides our personal view on the following topics: early diagnosis of idiopathic pulmonary fibrosis, current knowledge on the multidisciplinary team diagnosis of DPLDs and the diagnostic role of transbronchial cryobiopsy in this diagnostic setting, insights on the new entity of interstitial pneumonia with autoimmune features, and new therapeutic approaches for scleroderma-related interstitial lung disease.

Use of transbronchial cryobiopsy in the diagnosis of interstitial lung disease-a systematic review and cost analysis

BACKGROUND

Histological diagnosis by surgical lung biopsy for interstitial lung disease (ILD) is currently limited. Transbronchial cryobiopsy via flexible bronchoscope may this for more patients. The relative costs, diagnostic yields and safety of this approach and more traditional approaches have not been determined.

OBJECTIVES

To perform a systematic review and meta-analysis of transbronchial cryobiopsy, forceps transbronchial biopsy and video assisted (VATS) surgical lung biopsy assessing their relative diagnostic yields and safety. To perform a cost analysis to demonstrate any savings through change to the newer technique.

METHODS

We performed a systematic review of the literature using MEDLINE and EMBASE for all original articles on the diagnostic yield and safety of transbronchial cryobiopsy, forceps transbronchial biopsy and VATS-biopsy in ILD up to February 2016. Data were extracted on yield and complication rates, in addition to study characteristics. Theoretical cost analysis was performed from local institution financial data, 2015-16 reimbursement tariffs and results of the systematic review.

RESULTS

A meta-analysis of 11 investigations for transbronchial cryobiopsy, 11 for forceps transbronchial biopsy and 24 for VATS-biopsy revealed diagnostic yields of 84.4% (75.9-91.4%), 64.3% (52.6-75.1%) and 91.1% (84.9-95.7%), respectively. Pneumothorax occurred in 10% (5.4-16.1%) of transbronchial cryobiopsy procedures, moderate bleeding in 20.99% (5.6-42.8%), with three deaths reported. Surgical mortality was 2.3% (1.3-3.6%). Cost analysis demonstrated potential savings of £210 per patient in the first year and £647 in subsequent years.

CONCLUSIONS

Transbronchial cryobiopsy represents a potentially cost-saving approach to improve histological diagnosis in ILD, however is accompanied by a significant risk of moderate bleeding.

Pneumonic-type mucinous lung adenocarcinoma diagnosed by transbronchial cryobiopsy

Primary lung adenocarcinoma with lepidic growth can mimic diffuse pulmonary parenchymal processes like infectious pneumonia or idiopathic inflammatory pneumonitis. We report a case of subacute pneumonitis refractory to antibiotic therapy and empirical corticosteroids, proven to be diffuse mucinous adenocarcinoma with lepidic growth on transbronchial cryobiopsy.

Introduction of cryobiopsies in the diagnostics of interstitial lung diseases - experiences in a referral center

Introduction: Transbronchial cryobiopsies (cTBB) has emerged as a new method for obtaining lung tissue biopsies in the diagnosis of interstitial lung diseases (ILDs). Until now, it has been used in a few highly specialized interventional centers and has shown promising results in obtaining a definite diagnosis of ILDs. Method: All patients undergoing a cTBB between November 2015 and June 2016 were included in this case series study. Data on patient demographics, high-resolution computed tomography patterns, size and number of biopsies, histology patterns, the contribution to a confident diagnosis and complications were registered. Results: Thirty-eight patients underwent cTBB in the period. cTBB contributed to the diagnosis in 28 (74%) of the 38 patients. Only few complications were observed; pneumothorax was the most frequent complication (10 patients, 26%). In six patients, local bleeding occurred during the procedure and was easily controlled by a Fogarty catheter balloon and in some cases tranexamic acid. Conclusion: Performing cTBB in the diagnostics of ILDs is a safe and feasible procedure. cTBB resulted in a confident diagnosis in 74% of cases.