Tracheobronchopathia osteochondroplastica (TBPO) is a rare condition characterized by the abnormal growth of cartilage within the trachea and main bronchi, leading to airway obstruction. The exact cause of TBPO is unknown, but it is thought to be associated with chronic inflammation of the airways and abnormal cartilage metabolism. Since there is not a standardization, the treatment of the condition depends on disease symptoms, infection status and the severity of the airway obstruction. Here, we aimed to present three cases of severe TBPO successfully managed in our interventional pulmonology unit applying argon plasma coagulation and mechanical debulking with rigid bronchoscopy, as well as the literature review.

Asthma, a multifaceted chronic inflammatory disorder, concerns more than 300 million people worldwide. Recent developments have classified asthma into predominantly Type 2 (T2) high and T2 low categories. Specific biomarkers, more so for T2 inflammation, determine the nature of inflammation. Fractional exhaled nitric oxide (FeNO) has been presented as a reliable and non-invasive biomarker of T2, eosinophilic, airway inflammation. The synthesis of nitric oxide (NO) occurs through three isoforms of nitric oxide synthase (NOS), with inducible NOS being predominantly expressed in inflammatory conditions, particularly in response to cytokines like IL-4 and IL-13. Elevated FeNO levels have been related to disease activity and have guided clinical decisions regarding corticosteroid and biologic therapies. FeNO measurement has been found to be effective in diagnosing asthma and assessing treatment response and adherence. The practicality of FeNO as a prognostic tool for exacerbation risk is highlighted in recent studies. In particular, FeNO measurements may help establish individualized treatment approaches and optimized treatment modalities, including biological treatment based on inflammation profiles. However, despite its advantages, the results of FeNO levels can be faked by many factors, such as genetics, environmental conditions, and concomitant diseases. Considering all of these, it seems helpful to integrate FeNO measurement into clinical practice in comprehensive asthma management with cautious interpretation, thus improving patient outcomes.

Primary salivary gland-type lung cancers are extremely rare, accounting for less than 1% of all lung tumors. Hyalinizing clear cell carcinoma (HCCC) of the lung, an even rarer subtype, presents diagnostic challenges due to its similarity to other endobronchial lesions, such as carcinoid tumors or mucoepidermoid carcinoma. Here, we aimed to present a case of a 53-yearold male non-smoker who presented with recurrent respiratory symptoms. Initial chest X-ray showed consolidation, and subsequent computed tomography (CT) revealed a left lower lobe endobronchial nodule with postobstructive pneumonia. Positron emission tomography-CT imaging demonstrated mild F-18 fluorodeoxyglucose uptake, and bronchoscopy with biopsy led to the diagnosis of HCCC. The patient underwent a left lower lobectomy, and histopathological analysis confirmed the diagnosis. The fiveyear follow-up was unremarkable, with no signs of recurrence. This case underscores the importance of considering HCCC in the differential diagnosis of endobronchial lesions, particularly in non-smokers.