Diffuse alveolar hemorrhage (DAH) is a life-threatening and medical emergency that can be caused by numerous disorders and presents with hemoptysis, anemia, and diffuse alveolar infiltrates. Early bronchoscopy with bronchoalveolar lavage is usually required to confirm the diagnosis and rule out infection. Most cases of DAH are caused by capillaritis associated with systemic autoimmune diseases such as anti-neutrophil cytoplasmic antibody-associated vasculitis, anti-glomerular basement membrane disease, and systemic lupus erythematosus, but DAH may also result from coagulation disorders, drugs, inhaled toxins, or transplantation. The diagnosis of DAH relies on clinical suspicion combined with laboratory, radiologic, and pathologic findings. Early recognition is crucial, because prompt diagnosis and treatment is necessary for survival. Corticosteroids and immunosuppressive agents remain the gold standard. In patients with DAH, biopsy of involved sites can help to identify the cause and to direct therapy. This article aims to provide a general review of the causes and clinical presentation of DAH and to recommend a diagnostic approach and a management plan for the most common causes.

Background: In uncontrolled hemoptysis patient, bronchial arteriography and bronchial artery embolization (BAE) is a important procedure in diagnosis and treatment. The aim of this study is to assess the incidence of contrast-induced nephropathy and the risk factors of contrast-induced nephropathy (CIN) after bronchial arteriography and BAE. Methods: We retrospectively reviewed the medical records of the patients who underwent bronchial arteriography and BAE in two university hospitals from January 2003 to December 2011. CIN was defined as rise of serum creatinine more than 25% of baseline value or 0.5 mg/dL at between 48 hours and 96 hours after bronchial arteriography and BAE. We excluded patients who already had severe renal insufficiency (serum creatinine${\geq}4.0$) or had been receiving dialysis. Results: Of the total 100 screened patients, 88 patients met the enrollment criteria. CIN developed in 7 patients (8.0%). The mean duration between the exposure and development of CIN was $2.35{\pm}0.81$ days. By using multivariate analysis, serum albumin level was found to be significantly associated with the development of CIN (p=0.0219). Conclusion: These findings suggest that the incidence of CIN was higher than expected and patients with hypoalbuminemia should be monitored more carefully to prevent the development of CIN after bronchial arteriography and BAE.

Background: Although the lung is a common site of metastasis, endobronchial metastases (EBM) from extrathoracic malignancies are rare. Previous studies were retrospective reviews of the cases from each single institute, and the last one was performed between 1992 and 2002. We evaluated the characteristics of patients with EBM who had been diagnosed in recent 10 years in our hospital. Methods: We retrospectively reviewed 1,275 patients who had undergone diagnostic bronchoscopic procedures between 2001 and 2011. An EBM was defined as bronchoscopically notable lesion, which was histopathologically identical to the primary tumor. Results: A total of 18 cases of EBM were identified. The mean age was 53 years, and 12 cases of the 18 patients were female. The most common primary malignancies were colorectal cancer and breast cancer (4 cases each), followed by cervix cancer (3 cases) and renal cell carcinoma (2 cases). Cough was the most common symptom. The most common radiologic finding was atelectasis, which was identified in 27.7% of the cases. The median interval from the diagnosis of primary malignancy to the diagnosis of EBM was 14 months (range, 0-112 months). The median survival time from the diagnosis of EBM was 10 months (range, 1-39 months). Conclusion: EBM from extrathoracic malignancies were rare. Colorectal cancer and breast cancer were common as primary malignancies. Fiberoptic bronchoscopy should be performed in all patients, who are suspected of having EBM. If atypical clinical and pathological features are present, appropriate diagnostic studies should be undertaken.

We report a 54-year-old woman who presented with a well-defined, homogeneous, and non-enhancing mass in the retrobronchial region of the bronchus intermedius. The patient underwent endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for histological confirmation. Serous fluid was aspirated by EBUS-TBNA. Cytological examination identified an acellular smear with negative microbiological cultures. The patient was finally diagnosed with bronchogenic cysts by chest computed tomography (CT) and EBUS-TBNA findings. However, 1 week after EBUS-TBNA, the patient developed bronchogenic cyst rupture and pneumonia. Empirical antibiotics were administered, and pneumonia from the bronchogenic cyst rupture had resolved on follow-up chest CT. To our knowledge, this is the first reported case of pneumonia from bronchogenic cyst rupture after EBUS-TBNA.

We report a rare synchronous presentation of primary lung cancer and adrenal pheochromocytoma. A 59-year-old woman was diagnosed with right upper lobe non-small cell lung carcinoma measuring 2.8 cm and a right adrenal gland mass measuring 3.5 cm, which displayed increased metabolic activity on $^{18}F$-fluorodeoxyglucose positron emission tomography-computed tomography. The adrenal lesion was revealed to be asymptomatic. The patient underwent right adrenalectomy and histological examination revealed a pheochromocytoma. Ten days later, right upper lobectomy was performed for lung cancer. This case indicates that incidental adrenal lesions found in cases of resectable primary lung cancer should be investigated.

We report a rare case of lung disease caused by Mycobacterium lentiflavum in a previously healthy woman. A 54-year-old woman was referred to our hospital due to chronic cough and sputum. A computed tomography scan of the chest revealed bilateral bronchiectasis with bronchiolitis in the right middle lobe and the lingular division of the left upper lobe. Nontuberculous mycobacteria were isolated twice from three expectorated sputum specimens. All isolates were identified as M. lentiflavum by multilocus sequence analysis based on rpoB, hsp65, and 16S rRNA fragments. To the best of our knowledge, this is the first documented case of M. lentiflavum lung disease in an immunocompetent adult in Korea.

Mycobacterium chelonae lung disease is very rare. We report a case of lung disease caused by M. chelonae in a previously healthy woman. A 69-year-old woman was referred to our hospital because of hemoptysis. A computed tomography (CT) scan of the chest revealed bronchiolitis associated with bronchiectasis in the lingular division of the left upper lobe. Nontuberculous mycobacteria were isolated three times from sputum specimens. All isolates were identified as M. chelonae by various molecular methods that characterized rpoB and hsp65 gene sequences. Although some new lesions including bronchiolitis in the superior segment of the left lower lobe developed on the chest CT scan 35 months after diagnosis, she has been followed up without antibiotic therapy because of her mild symptoms. To the best of our knowledge, this is the first case of M. chelonae lung disease in Korea in which the etiologic organisms were confirmed using molecular techniques.