Cryobiopsy in Lung Cancer Diagnosis-A Literature Review

A Review of Endobronchial-Ultrasound-Guided Transbronchial Intranodal Forceps Biopsy and Cryobiopsy

Benign and malignant mediastinal lesions are not infrequently encountered in clinical practice. Mediastinoscopy has long been considered the gold standard in evaluating mediastinal pathology. Since its introduction into clinical practice, endobronchial-ultrasonography-guided transbronchial fine needle aspiration (EBUS-TBNA) has replaced mediastinoscopy as the initial procedure of choice to evaluate mediastinal lesions and to stage lung cancer. Its diagnostic yield in benign mediastinal lesions and less common malignancies, however, has remained limited. This has led different proceduralists to investigate additional procedures to improve the diagnostic yield of EBUS-TBNA. In recent years, different published reports concluded that the addition of EBUS-guided intranodal forceps biopsy (IFB) and transbronchial cryobiopsy (TBCB) to EBUS-TBNA increases the diagnostic yield especially in benign mediastinal lesions and uncommon mediastinal malignancies. The purpose of this review is to describe how EBUS-IFB and EBUS-TBCB are performed, to compare their diagnostic yields, and to discuss their limitations and their potential complications. In addition, the review will conclude with a proposed algorithm on how to incorporate EBUS-IFB and EBUS-TBCB into clinical practice.

Endobronchial Obstruction: A Case of Well-Differentiated Liposarcoma

Atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) is a rare subtype of endobronchial tumor that has been rarely reported in medical literature. Due to its low incidence, distinguishing it from endobronchial lipoma poses a significant diagnostic challenge, necessitating histopathologic and cytogenetic analysis. As of today, the treatment and surveillance protocols for these neoplasms remain poorly defined, often resulting in their misclassification and treatment as endobronchial lipomas. We present a case involving a 72-year-old male who presented with worsening dyspnea and cough. Diagnostic imaging revealed an endobronchial lesion obstructing the left main bronchus. The patient underwent a flexible bronchoscopy that identified a polypoid mass causing significant obstruction, which was subsequently resected via cryoablation. Histopathology confirmed ALT/WDL, supported by genetic analysis revealing chromosomal alterations. Following the intervention, symptoms resolved, with no recurrence on follow-up imaging. Differentiating ALT/WDL from endobronchial lipomas is necessary not only because it influences treatment decisions but also because it can significantly affect the prognosis of patients diagnosed with ALT/WDL. In this case, we emphasize the importance of considering ALT/WDL in the differential diagnosis of endobronchial tumors and highlight the use of flexible bronchoscopy as a viable substitute for rigid bronchoscopy, serving not only as a diagnostic tool but also as a therapeutic method.

Is the diagnostic yield of mediastinal lymph node cryobiopsy (cryoEBUS) better for diagnosing mediastinal node involvement compared to endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)? A systematic review

INTRODUCTION

New tools such as cryobiopsy of mediastinal lymph nodes (cryoEBUS) have been described to improve the diagnostic usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The literature suggests that this novel procedure could be associated with greater diagnostic usefulness than conventional EBUS-TBNA.

METHODS

To develop a systematic analysis and meta-analysis on the diagnostic diagnostic yield and safety of cryobiopsy of hilar and mediastinal adenopathies compared to EBUS-TBNA.

RESULTS

Seven studies that had included a total of 555 patients were considered in this review, with 365 (65.7%) of these patients having an etiology of malignant lymph node involvement. The overall diagnostic usefulness of cryoEBUS was higher compared to EBUS-TBNA (92% vs. 80%). However, when the results were analysed according to the specific aetiologies of the adenopathies, cryoEBUS was especially useful in cases of lymphomas or non-pulmonary carcinomas (83% vs. 42%) and in cases that were benign (87% vs. 60.1%), with no significant differences being found in specific cases of lung cancer. For lymphoma, cryoEBUS was diagnostic in 87% of cases compared to 12% for EBUS-TBNA and in addition, also allowed the characterisation of every lymphoma subtype. Genetic studies and immunohistochemical determination of PD-L1 was possible in almost all (97%) of the samples obtained by cryoEBUS, while this was only possible in 79% of those obtained by EBUS-TBNA. The most frequent complication was light bleeding, which was described in up to 85% of cases in some series.

CONCLUSION

CryoEBUS could represent a promising technique in the diagnostic algorithm used for mediastinal and hilar involvement. Although cryoEBUS did not significantly improve the diagnosis of lung cancer compared to EBUS-TBNA, the results were significantly better in patients with benign pathologies and other tumour types, including lymphomas. In addition, it seems that the samples obtained by cryoEBUS better defined the histological subtypes of lymphoma and allowed complete molecular characterisation in cases of lung cancer. The technique has proven to be safe and no serious complications were described after the procedure.

Invasive Diagnostic Procedures from Bronchoscopy to Surgical Biopsy-Optimization of Non-Small Cell Lung Cancer Samples for Molecular Testing

Background and Objectives: Treatment of advanced lung cancer (LC) has become increasingly personalized over the past decade due to an improved understanding of tumor molecular biology and antitumor immunity. The main task of a pulmonologist oncologist is to establish a tumor diagnosis and, ideally, to confirm the stage of the disease with the least invasive technique possible. Materials and Methods: The paper will summarize published reviews and original papers, as well as published clinical studies and case reports, which studied the role and compared the methods of invasive pulmonology diagnostics to obtain adequate tumor tissue samples for molecular analysis, thereby determining the most effective molecular treatments. Results: Bronchoscopy is often recommended as the initial diagnostic procedure for LC. If the tumor is endoscopically visible, the biopsy sample is susceptible to molecular testing, the same as tumor tissue samples obtained from surgical resection and mediastinoscopy. The use of new sampling methods, such as cryobiopsy for peripheral tumor lesions or cytoblock obtained by ultrasound-guided transbronchial needle aspiration (TBNA), enables obtaining adequate small biopsies and cytological samples for molecular testing, which have until recently been considered unsuitable for this type of analysis. During LC patients' treatment, resistance occurs due to changes in the mutational tumor status or pathohistological tumor type. Therefore, the repeated taking of liquid biopsies for molecular analysis or rebiopsy of tumor tissue for new pathohistological and molecular profiling has recently been mandated. Conclusions: In thoracic oncology, preference should be given to the least invasive diagnostic procedure providing a sample for histology rather than for cytology. However, there is increasing evidence that, when properly processed, cytology samples can be sufficient for both the cancer diagnosis and molecular analyses. A good knowledge of diagnostic procedures is essential for LC diagnosing and treatment in the personalized therapy era.

Endobronchial cryobiopsy may shorten the time to cancer diagnosis: a retrospective study

Endobronchial cryobiopsy from visualised intraluminal tumour lesions may decrease the rate of diagnostic failure and shorten the time to diagnosis https://bit.ly/3NkyJ98.

Feasibility and Safety of Transbronchial Lung Cryobiopsy for Diagnosis of Acute Respiratory Failure with Mechanical Ventilation in Intensive Care Unit

BACKGROUND

Acute hypoxemic respiratory failure is common in intensive care units (ICUs). Lung biopsies may be required to make a definitive diagnosis in patients with unknown etiologies. The feasibility of transbronchial lung cryobiopsy is undetermined in patients with respiratory failure in the ICU.

METHODS

Patients who underwent bronchoscopy examinations with transbronchial lung cryobiopsy (TBLC) between July 2018 and December 2019 were retrospectively analyzed through medical chart review. The procedures were performed by well-experienced interventional pulmonologists.

RESULTS

Ten patients underwent bronchoscopy examinations with TBLC in the ICU at Chang Gung Memorial Hospital during the study period. In all patients, the diagnosis was made via pathological analysis. One patient developed pneumothorax and required chest tube placement after the procedure. None of the patients had bleeding requiring blood transfusion, and no deaths were directly related to the procedure.

CONCLUSIONS

TBLC is a feasible technique to obtain lung pathology in patients with acute respiratory diseases of unknown etiologies. While the complication rate may be acceptable, the procedure should be performed by experienced interventional pulmonologists. However, airway blockers and fluoroscopy are highly recommended when used according to the current guideline. We do not encourage TBLC to be performed without having airway blockers available at the bedside.

The importance of endobag use with incision-protective devices in VATS lung resection: a preliminary study

OBJECTIVE

The advent of new techniques such as video-assisted thoracoscopic surgery (VATS) for the removal of lung segments leads to compression of the surgical specimen, with the possible dissemination of neoplastic cells. The sheer volume of surgeries performed using these techniques has caused many institutions to stop removing the surgical specimen using an endobag, even when retractors/protectors are used in the instrumentalization incision. This study aimed to collect data from patients undergoing lung resection by VATS and analyze the cytopathological results of the collected material.

RESULTS

A total of 47 endobag fluid samples were collected from patients who underwent VATS. The surgical specimen was subjected to histopathological analysis, and all patients underwent pathological TNM staging. In the cytopathological analyses, only 2 (4.3%) specimens of endobag fluid aspirate were positive for neoplastic cells. In these two cases, the tumors were peripheral, both with diagnoses of moderately differentiated adenocarcinoma and with classifications of T1bN0M0 and T3N0M0. These results indicate that although there is a low incidence of tumor cells in endobag fluid, it is always better to perform surgery using all available protective measures to avoid tumor implantation in the thoracic cavity to the greatest extent possible.

Diagnostic Yield of Transbronchial Cryobiopsy Guided by Radial Endobronchial Ultrasound and Fluoroscopy in the Radiologically Suspected Lung Cancer: A Single Institution Prospective Study

Transbronchial cryobiopsy (TBCB) is being studied in the diagnosis of peripheral lung lesions; however, there are only a few clinical studies around the world. The aim of our study was to evaluate the diagnostic values and safety of transbronchial cryobiopsy for radiologically suspected peripheral lung cancer. The prospective clinical study was executed from September 2019 to September 2021 at a tertiary clinical centre in Lithuania. A total of 48 patients out of 102 underwent combined procedures of transbronchial forceps biopsy (TBFB) and TBCB. Diagnostic values and safety outcomes of TBFB and TBCB were analysed. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were 72.9%, 100%, 100%, 7.7%, and 88.0% for TBFB, 85.1%, 100%, 100%, 12.5%, and 93% for TBCB, as well as 91.5%, 100%, 100%, 20.0% and 96.7% for the combined procedures, respectively, with a significantly higher accuracy for cryobiopsies compared to forceps biopsies (p < 0.05). The diagnostic values for transbronchial cryobiopsies were similar, irrespective of the radial mini probe endobronchial ultrasound (RP-EBUS) position, lesion size or bronchus sign, however, the sensitivity of the combined procedures in cases with RP-EBUS adjacent to the target was significantly higher compared to TBFB (86.2% vs. 64.3%, p = 0.016). Samples of cryobiopsies were significantly larger than forceps biopsies (34.62 mm2 vs. 4.4 mm2, p = 0.001). The cumulative diagnostic yield of transbronchial cryobiopsy was 80.0% after the second biopsy and reached a plateau of 84.1% after four biopsies. No severe bleeding, pneumothorax, respiratory failure or death was registered in our study. TBCB is a potentially safe procedure, which increases diagnostic values in diagnosing peripheral lung lesions compared to TBFB.