This study evaluated 330 elderly patients, including both inpatients and outpatients, to investigate the frequency, morphology, and distribution of tracheobronchial calcification using computed tomography, as well as its association with cardiovascular calcification. Tracheobronchial calcification was found to be more common in female patients and was frequently accompanied by respiratory complications such as airway deformation, mucus plugging, atelectasis, and aspiration pneumonia. Calcifications of the aorta and coronary arteries were also commonly observed in conjunction. These findings suggest that tracheobronchial calcification may influence respiratory function, complicate perioperative airway management, and contribute to the development of cardiovascular diseases. In an aging society, awareness of the clinical implications of tracheobronchial calcification will be increasingly important for comprehensive care of the elderly.

A 72-year-old woman presented with dyspnea and was referred to our hospital after being diagnosed with pneumonia at a previous clinic. Imaging revealed bilateral pneumonia, and she was admitted to the intensive care unit due to respiratory failure. A nasopharyngeal swab tested positive for human metapneumovirus (hMPV) by multiplex PCR and rapid antigen testing. Sputum culture yielded no significant bacterial pathogens, and a diagnosis of severe pneumonia caused by hMPV was made. The patient improved with steroid pulse therapy and supportive care under mechanical ventilation. Reports of severe community-acquired pneumonia due to hMPV in adults are rare, and we report this valuable case.

A 61-year-old, immunocompetent woman presented with fever, chills, and productive cough. Chest computed tomography revealed a 4.0-cm, mass-like consolidation surrounded by ground-glass opacity in the right lung and mediastinal lymphadenopathy. Multiplex PCR of a nasopharyngeal swab was positive for adenovirus and human coronavirus OC43. Despite empiric antibiotic therapy, the patient’s respiratory status worsened, prompting bronchoscopy on hospital day 4. Bronchoalveolar lavage fluid showed elevated lymphocytes but was PCR-negative for adenovirus. A transbronchial lung cryobiopsy (TBLC) of the right lower lobe revealed marked lymphocytic infiltration and alveolar epithelial injury consistent with viral pneumonia, although neither intranuclear inclusion bodies nor smudge cells were observed. Based on the clinical course and histopathological findings, adenovirus was considered the most likely causative pathogen. Corticosteroid therapy for suspected postinfectious organizing pneumonia resulted in progressive clinical and radiological improvement. The patient was discharged on Day 19 without recurrence, and the steroid therapy was tapered over approximately two and a half months until discontinuation. The present case illustrates the ability of adenovirus pneumonia to mimic bacterial pneumonia or a malignancy on an imaging study even in immunocompetent adults. The combined use of multiplex PCR and TBLC was instrumental in establishing the present diagnosis. As multiplex PCR use becomes more widespread, adenovirus is increasingly likely to be recognized as an important cause of community-acquired pneumonia regardless of patients’ immune status.

A 67-year-old man with a history of pulmonary tuberculosis and pulmonary Mycobacterium avium disease presented with fever and right-sided chest pain for one month. He was diagnosed with an infectious pulmonary cyst caused by Mycobacterium intracellulare. Antimicrobial therapy alone was insufficient for fever resolution, and prolonged percutaneous drainage was required. Additionally, persistent air leakage was successfully managed with bronchial occlusion using an endobronchial Watanabe spigot. Although infectious pulmonary cysts caused by nontuberculous mycobacteria (NTM) are rare, they should be considered in the differential diagnosis of patients with a history of NTM disease.

A 29-year-old woman with a history of bronchial asthma and Sjögren’s syndrome presented to a referring hospital with fever, cough, and respiratory failure. CT showed multiple ground-glass opacities in both lungs, prompting her referral to our hospital for further evaluation and testing. Human metapneumovirus (hMPV) was detected through multiplex polymerase chain reaction (PCR) analysis of a nasal swab, whereas sputum cultures showed no significant findings. Consequently, antibiotics were discontinued. The patient improved clinically with symptomatic treatment alone. This rare case of hMPV pneumonia in a young adult highlights the value of multiplex PCR in preventing unnecessary antibiotics.

Re-expansion pulmonary edema (RPE), caused by spontaneous pneumothorax, is a complication that can lead to death in severe cases, and rapid lung re-expansion has been reported as a risk factor for developing this complication. We experienced a case of RPE due to uncontrolled subcutaneous emphysema, which occurred after clamping a large-diameter drain despite attempts to slowly inflate the lung. On the other hand, a different patient with a small-diameter drain developed RPE after surgery because the lung did not expand sufficiently. Since it is often difficult to obtain appropriate lung re-expansion at the intended rate, it is important to always be prepared for the occurrence of severe RPE when treating patients with spontaneous pneumothorax, and to avoid missing the opportunity to perform tracheal intubation when treating cases who demonstrate RPE.

A 49-year-old man presented with seizures and was referred to a previous hospital for emergency treatment. He was diagnosed with adenocarcinoma of the right lower lobe of the lung, and multigene testing confirmed ALK-positive lung cancer. Upon transfer to our hospital for further treatment, a pleural effusion test performed at the previous hospital revealed the presence of tubercle bacilli, leading to a diagnosis of tuberculous pleurisy. Alectinib therapy was initiated the day after admission, and concurrent anti-tuberculosis therapy was also initiated on the 15th day. Four months after initiation of alectinib treatment, the tumor showed no significant progression. This case suggests that the anti-tumor efficacy of alectinib may be preserved even when co-administered with anti-tuberculosis drugs that have CYP3A4-inducing effects.

A 67-year-old man presented with back pain and was referred to our hospital after contrast-enhanced computed tomography (CT) at a local clinic suggested lung cancer. Bronchoscopy revealed small cell carcinoma, and chest and abdominal CT showed mediastinal lymphadenopathy and multiple liver metastases, leading to a diagnosis of extensive-stage small cell lung cancer. He was admitted for first-line chemotherapy, and a pre-treatment CT scan showed a small pericardial effusion. On hospital day 3, he developed dyspnea, and follow-up CT revealed increased pleural and pericardial effusion. Although pericardiocentesis was considered, it was deemed technically difficult and postponed. On hospital day 4, he developed tachycardia and hypotension, raising concern for cardiac tamponade. Emergent pericardiocentesis was performed, and purulent fluid was obtained. Pyogenic pericarditis was diagnosed, and pericardial drainage along with antimicrobial therapy was initiated. Despite these interventions, circulatory failure progressed, and the patient died on hospital day 8. This case highlights a rare but fatal complication of small cell lung cancer: pyogenic pericarditis progressing to cardiac tamponade. Although timely recognition and treatment are essential, the clinical course can be fulminant.

A female patient in her 60s was diagnosed with lung adenocarcinoma harboring an EGFR/exon 19 deletion mutation (cT1cN2bM1a(PLE), cStage IVA). Osimertinib was initiated but had to be discontinued after three months because of the development of grade 4 lung injury (Common Terminology Criteria for Adverse Events, Version 5.0), necessitating steroid therapy. One month after drug withdrawal, erlotinib combined with ramucirumab was commenced. During the subsequent eight months, no recurrence of lung injury was observed. Tyrosine kinase inhibitors play a crucial role in the management of EGFR mutation–positive lung cancer, and we explored the potential for reintroducing tyrosine kinase inhibitors following osimertinib-induced lung injury.

An 86-year-old man was referred to our hospital for further evaluation of abnormal chest X-ray findings. Contrast-enhanced CT revealed a lung mass measuring approximately 7 cm in the left lower lobe, hilar and mediastinal lymph node enlargement, and multiple liver masses, suggesting primary lung cancer with multiple metastases. Histopathological examination of the transbronchial biopsy specimens revealed proliferation of small, round, atypical cells with a high nuclear-to-cytoplasmic ratio and dense chromatin. These findings initially suggested small cell lung cancer. However, the diagnosis of small cell lung cancer seemed unlikely because he had never smoked and the pro-GRP and NSE levels were not elevated. Immunohistochemistry findings including positivity of Melan-A and vimentin ultimately led to a pathological diagnosis of small cell variant of malignant melanoma. No skin lesions suggestive of melanoma were found. The lung mass was solitary. Based on these findings, a diagnosis of primary malignant melanoma of the lung (cT4N3M1c, based on the TNM classification for lung cancer) was made. He declined treatment for malignant melanoma and received comfort care. He died approximately 8 months after the initial presentation. Because primary malignant melanoma of the lung may have similar clinical and histopathological features to small cell lung cancer as in this case, these two malignancies should be cautiously differentiated.

Chronic Pseudomonas aeruginosa pneumonia is a clinical problem in patients with immunodeficiency and serious underlying diseases that has increased in recent years. Chronic P. aeruginosa pneumonia is difficult to treat due to the development of drug resistance and the limited oral antibacterial options. In this report, we report two cases of chronic P. aeruginosa pneumonia with repeatedly relapse over a short period of time that were successfully treated with tobramycin inhalation solution (TIS). TIS is effective for P. aeruginosa pneumonia associated with cystic fibrosis (CF), which is currently covered by insurance. It is also useful for infection control of non-CF P. aeruginosa pneumonia and is expected to have expanded indications in the future.

A 76-year-old man was diagnosed with lung adenocarcinoma (cT4N3M1a, Stage IVA, EGFR mutation-positive, PD-L1 expression: 1–24%). Following disease progression after first-line treatment with osimertinib, PET-CT revealed abnormal uptake in the stomach. Subsequent upper gastrointestinal endoscopy identified advanced gastric cancer (cT3N1M0, Stage IIB), leading to a diagnosis of multiple primary malignancies. As second-line therapy for lung cancer, combination chemoimmunotherapy with carboplatin, pemetrexed, and pembrolizumab was administered, resulting in a partial response in the lung cancer and a complete response in the gastric cancer. This case suggests that chemoimmunotherapy may be a feasible therapeutic option for selected patients with multiple primary malignancies.

The patient was a 49-year-old man with a history of pulmonary tuberculosis treated at the age of 20. He was referred to our hospital after a routine checkup revealed abnormal shadows on chest imaging. CT revealed an old tuberculous lesion with calcification and 3 pulmonary nodules in the right upper lobe. A biopsy of 1 of the nodules confirmed a diagnosis of a typical carcinoid tumor. The patient underwent robot-assisted right upper lobectomy with mediastinal lymph node dissection. Histopathological examination revealed that the remaining 2 lesions were papillary adenocarcinoma and large cell neuroendocrine carcinoma. This is a rare case of synchronous triple primary lung cancers of different histological types arising in the right upper lobe against a background of old pulmonary tuberculosis in a middle-aged patient. The case suggests a possible association between prior tuberculosis and lung carcinogenesis.

Duchenne muscular dystrophy (DMD) is a progressive muscle weakness disease that is accompanied by spinal column and tracheal deformities, respiratory muscle disorders, and heart failure in the terminal stages, resulting in respiratory failure and requiring ventilator management in most cases. The case is a 36-year-old male. He developed DMD in childhood and was managed with noninvasive positive pressure ventilation as his symptoms progressed, but he presented to our hospital for emergency care due to deterioration of his respiratory condition. This case presented with terminal DMD pathology, and the severe deformities of the trachea and spine made securing a reliable airway extremely challenging. However, it served as a case that reaffirmed various critical points to emphasize in airway management. Therefore, based on a review of the literature, we report this case.