Background: Rapid on-site evaluation (ROSE) is increasingly being performed during radial endobronchial ultrasound (R-EBUS)-guided transbronchial lung biopsy (TBLB) for peripheral pulmonary lesions. Although ROSE can support immediate clinical decision-making, discrepancies with the final diagnosis of TBLB occasionally occur, potentially leading to inappropriate management. The clinical and radiological characteristics associated with such discrepancies remain unclear.

Materials and Methods: We retrospectively analyzed 361 patients who underwent R-EBUS-guided TBLB with ROSE of touch imprint cytology (ROSE-TIC) between October 2020 and December 2023. The ROSE-TIC results (positive or negative for malignancy) were compared with the pathological diagnoses by TBLB. Among patients diagnosed with malignancy, the clinical and radiological features were compared between the ROSE-TIC–positive and false-negative groups. Additionally, we investigated the risk factors for false negatives in ROSE-TIC.

Results: Of the 361 patients, 221 were diagnosed with malignancy by TBLB; all these cases were ultimately confirmed as malignant on final diagnosis. Of the 221 patients with malignancy, 196 were ROSE-TIC–positive and 25 were false-negative. The false-negative group had significantly higher rates of part-solid nodules on computed tomography, "adjacent to" findings on EBUS, and smaller lesion sizes than the positive group. In a multivariate logistic regression analysis, part-solid nodule (versus solid nodule) (adjusted odds ratio [OR] 4.68; 95% confidence interval [CI] 1.46-15.0; p = 0.010) and smaller lesion size (adjusted OR 0.62; 95% CI 0.41-0.94; p = 0.023) were independently associated with false negatives.

Conclusions: Part-solid nodules, compared with solid nodules and smaller lesion sizes were associated with ROSE-TIC false-negative results. Clinicians may need to exercise caution when interpreting negative ROSE-TIC findings in such cases, and tissue sampling may be considered, while acknowledging the potential risk of false-negative ROSE-TIC results.

Endobronchial endometriosis represents an uncommon form of pulmonary endometriosis. A 23-year-old female was hospitalized due to recurrent hemoptysis. Chest computed tomography revealed ground-glass opacities that appeared synchronized with her menstrual cycle. Bronchoscopic examination revealed reddish swollen epithelium, prominent subepithelial blood vessels, and multiple red subepithelial lesions in the bronchial epithelium. Given the temporal association of hemoptysis with menstruation, ground-glass opacities in the lung field, and endobronchial abnormalities, along with a history of induced abortion and heavy menstrual bleeding, endobronchial endometriosis was suspected. Treatment with progestin completely resolved her hemoptysis and the abnormal endobronchial findings, and she was subsequently diagnosed with endobronchial endometriosis. To our knowledge, this is the first reported case demonstrating improvement in endobronchial lesions before and after progestin treatment in a patient with endobronchial endometriosis.

Balloon dilatation for bronchoscope delivery (BDBD) using the single-use bronchial dilatation catheter known as "SUKEDACHI" has proved useful for diagnosing peripheral pulmonary nodules. We report three cases-lung adenocarcinoma, small-cell lung cancer, and pulmonary cryptococcosis-diagnosed using the SUKEDACHI balloon combined with an ultrathin bronchoscope. In each case, the subpleural pulmonary nodule was successfully diagnosed by performing BDBD with the SUKEDACHI balloon and ultrathin bronchoscope after unsuccessful attempts with ultrathin and/or thin bronchoscopy using endobronchial ultrasonography with a guide sheath. Our case series highlights the potential utility of the SUKEDACHI balloon with ultrathin bronchoscopy as an effective approach for diagnosing subpleural pulmonary nodules.

Bronchoscopic lung volume reduction (BLVR) is a minimally invasive treatment for severe chronic obstructive pulmonary disease (COPD). However, its efficacy and safety in cases complicated by airway foreign bodies remain unclear. We report the case of a 72-year-old man with severe COPD who had a denture lodged in the left B6 segment and for whom general anesthesia was considered high-risk. After confirming the absence of collateral ventilation in the right lower lobe using the Chartis system, Zephyr valves were placed in the right B6-B10 segments. Postoperatively, collapse of the right lower lobe and re-expansion of the right upper and middle lobes were confirmed, which was associated with a significant improvement in forced expiratory volume in 1 second. At the 12-month follow-up, no adverse events, including pneumothorax or COPD exacerbation, were observed. This case suggests that BLVR can be performed safely and effectively, even in patients with severe COPD complicated by an airway foreign body, provided that appropriate evaluation and careful target lobe selection are undertaken.

Malignant lymphoma arising from the posterior cervical tracheal region is extremely rare and may cause severe respiratory failure. We report the case of a 64-year-old woman who initially presented with throat discomfort and subsequently developed dyspnea and upper airway stridor. Computed tomography showed a solid tumor measuring 38 mm at the right posterolateral aspect of the trachea, resulting in airway narrowing to 8 mm in diameter. Bronchoscopic examination revealed compressive stenosis of the dorsal tracheal wall in the subglottic area, and six biopsy specimens were obtained. While waiting for the pathological diagnosis, the patient's respiratory condition deteriorated, and the tracheal lumen further narrowed to 6 mm. Corticosteroid therapy was initiated, leading to modest clinical improvement. Immunohistochemical analysis confirmed stage IE diffuse large B-cell lymphoma (DLBCL), and R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy was subsequently initiated. After the first treatment cycle, the tumor had almost completely regressed. This case highlights the importance of prompt histopathological diagnosis and appropriate airway management. Although DLBCL can progress rapidly, it responds well to corticosteroids and chemotherapy, and timely intervention may lead to favorable clinical outcomes.

This case report describes the management of a large tracheoesophageal fistula in a 63-year-old male patient with advanced upper oesophageal cancer. Following chemoradiotherapy (cisplatin, 5-fluorouracil, and 60 Gy radiation), disease progression led to the formation of a 27 mm fistula due to direct tumour infiltration, causing recurrent aspiration pneumonia. Bronchoscopy revealed that the fistula extended from 23 mm to 50 mm below the vocal cords with surrounding ulceration. Oesophageal stent placement was deemed unfeasible due to severe mucosal fragility and cancerous infiltration. After multidisciplinary consultation, a bronchial approach was selected. A 20 mm × 80 mm covered self-expanding metallic stent was successfully placed to fully cover the fistula. Post-procedure, the patient experienced significant improvement in sputum production, dyspnoea, and quality of life, with complete resolution of recurrent aspiration pneumonia until transfer to hospice care. Importantly, airway stenting primarily contributed to symptom relief and quality-of-life improvement rather than prolongation of survival. Tracheoesophageal fistulas occur in 5%-15% of patients with oesophageal cancer, with higher rates following chemoradiotherapy. Despite poor prognosis (median survival 3-4 months), airway stenting represents a valuable palliative option for improving quality of life when oesophageal approaches are contraindicated.

A woman diagnosed with Mycobacterium avium pulmonary disease at age 62 initially received clarithromycin (CAM)-based therapy, which was modified due to adverse effects. Despite treatment, the lesion worsened with hemoptysis, leading to bronchial artery embolization (BAE) and a left upper lobectomy. Treatment was discontinued when clinical stability was achieved after the lobectomy. At 75 years of age, new infiltrates appeared in the residual lung. Treatment was initiated with azithromycin (AZM), sitafloxacin (STFX), and intravenous amikacin (AMK). At 77 years of age, Mycobacterium florentinum was isolated from bronchial washing fluid, and drug susceptibility testing revealed CAM resistance. Despite various regimens, including AZM, moxifloxacin, ethambutol (EB), and AMK, multiple hemoptyses recurred, requiring BAE. The regimen was later rearranged to EB, STFX, AZM, and AMK; however, M. florentinum continued to be isolated in subsequent cultures. M. florentinum is a rare pulmonary mycobacterial pathogen, and reports of CAM-resistant strains are limited. However, this case shows that long-term antibiotic use may result in species replacement from M. avium to M. florentinum, highlighting the need for mycobacterial re-evaluations, especially when a rearrangement of nontuberculous mycobacterial treatment is considered due to a recurrent or refractory disease course. In this regard, bronchoscopy plays a key role in diagnosis.

Pulmonary metastases from prostate cancer have diverse imaging findings, most frequently solitary or multiple nodules, and rarely present with prominent respiratory symptoms. Limited or diffuse pulmonary metastases may mimic pneumonia-like radiographic patterns, potentially leading to misdiagnosis and inappropriate treatment. We describe the case of a 66-year-old man with a 7-month history of progressive dyspnea who was initially suspected to have an infectious or inflammatory lung disease. Despite empirical therapy with antibiotics, corticosteroids, and inhaled bronchodilators, the symptoms and radiographic abnormalities worsened. Chest computed tomography (CT) revealed diffuse bilateral airway-centered granular patterns, ground-glass opacities, patchy consolidations, small nodules, and bronchial wall thickening. Laboratory tests revealed elevated serum Krebs von den Lungen-6 (sKL-6) and prostate-specific antigen (PSA) levels, non-elevated serum lung cancer tumor marker levels, and negative sputum cultures. Histopathological examination of the transbronchial lung biopsy specimen revealed adenocarcinoma. 18F-fluorodeoxyglucose positron emission tomography/CT and prostate biopsy confirmed prostate cancer, and thus, pulmonary metastases from prostate cancer were diagnosed. Bilateral orchiectomy resulted in marked clinical improvement, regression of pulmonary lesions, and substantial reductions in serum PSA and sKL-6 levels. Thus, pulmonary metastases from prostate cancer may initially present with respiratory symptoms and atypical imaging features; early recognition can enable timely intervention and favorable outcomes.

Otsuji-to is a Kampo medicine used to treat hemorrhoids and constipation. Although rare, cases of drug-induced interstitial lung disease (DIILD) associated with Otsuji-to have been reported. Herein, we present three cases of DIILD caused by Otsuji-to. Bronchoalveolar lavage (BAL) findings were analyzed in two cases. Case 1 included an 88-year-old male presented with fever; onset occurred 91 days after Otsuji-to administration. Chest computed tomography (CT) showed a non-specific interstitial pneumonia (NSIP) pattern. BAL revealed lymphocytes at 27.8%, eosinophils at 8.6%, and a CD4/CD8 ratio of 0.47. The patient was treated with steroids. Case 2 included a 77-year-old male presented with fever; onset occurred at 37 days after Otsuji-to administration. Chest CT showed an NSIP pattern. BAL revealed lymphocytes at 80.4%, eosinophils at 1.8%, and a CD4/CD8 ratio of 0.33. The patient was also treated with steroids. Case 3 included a 77-year-old male presented with fever; onset occurred 34 days after Otsuji-to administration. Chest CT showed a non-cardiogenic pulmonary edema pattern. BAL was not performed and treatment included steroids and tacrolimus. Clinicians should monitor patients for fever for up to 3 months after initiating Otsuji-to administration. In two cases, BAL showed lymphocyte predominance and a low CD4/CD8 ratio, consistent with typical findings in Kampo-related DIILD. Treatment involves discontinuation of the drug and administration of steroids; however, immunosuppressants may be beneficial in refractory cases.

We report a case of an 80-year-old woman who was incidentally found to have an abnormal chest opacity in the absence of any symptoms. Chest computed tomography demonstrated a slight tendency toward interval regression, leading to an initial suspicion of mucoid impaction. However, bronchoscopy was subsequently performed, and a diagnosis of squamous cell carcinoma was established. In patients without symptoms, it may be difficult to exclude lung cancer based solely on imaging findings, even when a lesion shows a regressive course.

Endobronchial hamartomas are rare benign tumors in the airway. Establishing a histopathological diagnosis using conventional bronchoscopic forceps biopsy can be challenging because these tumors frequently contain hard cartilaginous components. Herein, we report a case of an endobronchial hamartoma diagnosed using a tissue sample obtained from transbronchial lung cryobiopsy. A 64-year-old man was referred to our hospital for further evaluation of a persistent pulmonary lesion after treatment for bacterial pneumonia. Chest computed tomography revealed a ring-shaped calcified lesion at the entrance of the left B³b bronchus with distal atelectasis. Bronchoscopy demonstrated a pedunculated polypoid lesion occupying most of the bronchial lumen. Conventional forceps biopsy failed to obtain sufficient tissue for diagnosis. Transbronchial lung cryobiopsy was subsequently performed, which yielded an adequate specimen containing cartilaginous and mesenchymal components, leading to a histopathological diagnosis of endobronchial hamartoma. The patient remained clinically stable without recurrence of respiratory infection during 2 years of follow-up. This case suggests that transbronchial lung cryobiopsy may be a useful bronchoscopic diagnostic option for selected cases of endobronchial hamartoma when conventional forceps biopsy is insufficient.

Introduction: Rigid bronchoscopy is a valuable tool for airway interventions. However, its use is limited in Japan owing to the procedure's infrequency and the challenges of acquiring and maintaining proficiency. Although our current team initially had no specialists experienced in airway intervention, increasing requests for airway stenting from other departments prompted us to establish the necessary infrastructure to provide these procedures.

Technical Report: Before implementation, staff underwent training in rigid bronchoscopy techniques, simulation using three-dimensional image reconstruction, and comprehensive consultation with anesthesiologists. For the initial procedure, a physician experienced in rigid bronchoscopy was invited to perform the procedure while the team observed via audiovisual aids. Subsequent procedures were performed independently with ongoing training. Between January 2023 and December 2025, seven airway interventions were performed using rigid bronchoscopy. These included four patients who underwent stent placement for fistulas, two patients with tumor-related stenosis treated with core out and stent placement, and one patient who received hemostasis for airway bleeding. All procedures were completed without complications, leading to improvements in respiratory and systemic status.

Conclusions: Rigid bronchoscopy can be safely introduced for various indications, even by a team with limited prior experience, when implemented through a structured, stepwise approach with meticulous planning and preparation.