Purpose: NUT carcinoma (NC) is a solid tumor caused by the rearrangement of NUTM1 that usually develops in midline structures, such as the thorax. No standard treatment has been established despite high lethality. Thus, we investigated whether targeting the junction region of NUTM1 fusion breakpoints could serve as a potential treatment option for NC. Materials and Methods: We designed and evaluated a series of small interfering RNAs (siRNAs) targeting the junction region of BRD4-NUTM1 fusion (B4N), the most common form of NUTM1 fusion. Droplet digital polymerase chain reaction using the blood of patients was also tested to evaluate the treatment responses by the junction sequence of the B4N fusion transcripts. Results: As expected, the majority of NC fusion types were B4N (12 of 18, 67%). B4N fusion-specific siRNA treatment on NC cells showed specific inhibitory effects on the B4N fusion transcript and fusion protein without affecting the endogenous expression of the parent genes, resulting in decreased relative cell growth and attenuation of tumor size. In addition, the fusion transcript levels in platelet-rich-plasma samples of the NC patients with systemic metastasis showed a negative correlation with therapeutic effect, suggesting its potential as a measure of treatment responsiveness. Conclusion This study suggests that tumor-specific sequences could be used to treat patients with fusion genes as part of precision medicine for a rare but deadly disease.

Background: Paradoxical responses (PR) occur more frequently in lymph node tuberculosis (LNTB) than in pulmonary tuberculosis and present difficulties in differential diagnosis of drug resistance, new infection, poor patient compliance, and adverse drug reactions. Although diagnosis of mediastinal LNTB has become much easier with the development of endosonography, limited information is available. The aim of this study was to investigate the clinical course of mediastinal LNTB and the risk factors associated with PR. Methods: Patients diagnosed with mediastinal LNTB via endosonography were evaluated retrospectively between October 2009 and December 2019. Multivariable logistic regression was applied to evaluate the risk factors associated with PR. Results: Of 9,052 patients who underwent endosonography during the study period, 158 were diagnosed with mediastinal LNTB. Of these, 55 (35%) and 41 (26%) concurrently had pulmonary tuberculosis and extrapulmonary tuberculosis other than mediastinal LNTB, respectively. Of 125 patients who completed anti-tuberculosis treatment, 21 (17%) developed PR at a median of 4.4 months after initiation of anti-tuberculosis treatment. The median duration of anti-tuberculosis treatment was 6.3 and 10.4 months in patients without and with PR, respectively. Development of PR was independently associated with age < 55 years (adjusted odds ratio [aOR], 5.72; 95% confidence interval [CI], 1.81–18.14; P = 0.003), lymphocyte count < 800/μL (aOR, 8.59; 95% CI, 1.60–46.20; P = 0.012), and short axis diameter of the largest lymph node (LN) ≥ 16 mm (aOR, 5.22; 95% CI, 1.70–16.00; P = 0.004) at the time of diagnosis of mediastinal LNTB. Conclusion As PR occurred in one of six patients with mediastinal LNTB during antituberculosis treatment, physicians should pay attention to patients with risk factors (younger age, lymphocytopenia, and larger LN) at the time of diagnosis.

Recurrent respiratory papillomatosis (RRP) is a chronic disease related to human papillomavirus infection. The standard treatment of RRP is surgical resection of the lesion, but due to frequent recurrence, a combination of various adjuvant therapies has been attempted. Herein, we present the first case of RRP to whom intravenous cidofovir was administered as an adjuvant therapy in Korea. A 9-year-old boy was admitted due to hoarseness, stridor and breathing difficulty. At 10 months of age, he was diagnosed with RRP in the upper airway and thereafter he had repeatedly undergone surgical removal. During this hospitalization, papilloma was found again from the superior glottis to the inferior glottis and surrounding the trachea at the age of 9 years. In addition, well-defined nodular lesions were newly found on both lung fields, and a pathologic examination revealed a squamous papilloma with highgrade dysplasia, human papilloma virus types 6, 11, and 40 (low-risk type). Because of the frequent recurrence of papilloma in the upper airway as well as lung involvement, he underwent 38 injections of intravenous cidofovir for 2 years. During treatment, the intervals required for surgical removal of the mass causing upper airway obstruction were prolonged from an average of 37.3 to 74.6 days without serious side effects. However, intravenous cidofovir treatment had no effect on the lung lesion. This case shows that an intravenous cidofovir administration can be used as an adjuvant therapy in a child with RRP to relieve the upper airway obstruction, although this treatment does not cure the disease.

Although the typical CT findings of Pneumocystis jiroveci pneumonia (PJP) include diffuse or multifocal areas of ground-glass opacities in both lungs, it can also rarely manifest as multiple pulmonary nodules. We report a rare case of atypical PJP in an immunocompromised patient with multiple myeloma, presenting as widespread ground-glass opacities and multiple necrotic subpleural nodules in both lungs on CT, which proved to be granulomatous PJP on percutaneous transthoracic needle biopsy.

Vasculitis is a systemic disease, characterized by inflammation of the vascular wall. Although rare, it is sometimes life-threatening due to diffuse pulmonary hemorrhage or acute glomerulonephritis. Besides primary vasculitis, whose cause is unknown, numerous conditions such as autoimmune diseases, drugs, infections, and tumors can cause secondary vasculitis. Vasculitis displays various non-specific symptoms, signs, and laboratory findings; hence, diagnosis of the disease requires integration of various results including clinical features, imaging findings, autoantibody tests, and pathological findings. In this review, we have discussed the clinical, radiologic, and pathological features of vasculitis. Further, we elaborated the imaging findings and differential diagnosis of typical vasculitis that frequently involves the lung and introduced a new international classification of vasculitis, the Diagnostic and Classification Criteria in Vasculitis.

Following the introduction of a novel pathological concept of usual interstitial pneumonia (UIP) by Liebow and Carrington in 1969, diffuse interstitial pneumonia has evolved into UIP, nonspecific interstitial pneumonia (NSIP), and interstitial lung abnormality (ILA); the histopathological and CT findings of these conditions reflect the required multidisciplinary team approach, involving pulmonologists, radiologists, and pathologists, for their diagnosis and management. Concomitantly, traction bronchiectasis and bronchiolectasis have been recognized as the most persistent and important indices of the severity and prognosis of fibrotic lung diseases. The traction bronchiectasis index (TBI) can stratify the prognoses of patients with ILAs. In this review, the evolutionary concepts of UIP, NSIP, and ILAs are summarized in tables and figures, with a demonstration of the correlation between CT findings and pathologic evaluation. The CT-based UIP score is being proposed to facilitate a better understanding of the spectrum of pulmonary fibrosis, from ILAs to UIP, with emphasis on traction bronchiectasis/bronchiolectasis.

Invasive fungal infection (IFI) is a serious threat to pediatric patients with cancer given high morbidity and mortality. We present an 18-year-old male with precursor T-cell lymphoblastic leukemia who developed Pancoast syndrome, presented with paresthesia and numbness in the right shoulder and arm during a neutropenic fever period. He was diagnosed with pneumonia in the right upper lung field. He was later found to have an invasive pulmonary fungal infection caused by multiple fungi species, including Rhizomucor, confirmed by histology and polymerase chain reaction (PCR) (proven infection), Penicillium decumbens diagnosed by PCR, and Aspergillus suspected from galactomannan assay (probable infection). Unfortunately, the patient's condition further worsened owing to the aggravation of leukemia, chemotherapy-induced neutropenia, and bacterial coinfection, leading to multiorgan failure and death. Here, we report a case of IFI caused by multiple fungal species that presented as Pancoast syndrome.

Vasculitis is a systemic disease, characterized by inflammation of the vascular wall. Although rare, it is sometimes life-threatening due to diffuse pulmonary hemorrhage or acute glomerulonephritis. Besides primary vasculitis, whose cause is unknown, numerous conditions such as autoimmune diseases, drugs, infections, and tumors can cause secondary vasculitis. Vasculitis displays various non-specific symptoms, signs, and laboratory findings; hence, diagnosis of the disease requires integration of various results including clinical features, imaging findings, autoantibody tests, and pathological findings. In this review, we have discussed the clinical, radiologic, and pathological features of vasculitis. Further, we elaborated the imaging findings and differential diagnosis of typical vasculitis that frequently involves the lung and introduced a new international classification of vasculitis, the Diagnostic and Classification Criteria in Vasculitis.

Following the introduction of a novel pathological concept of usual interstitial pneumonia (UIP) by Liebow and Carrington in 1969, diffuse interstitial pneumonia has evolved into UIP, nonspecific interstitial pneumonia (NSIP), and interstitial lung abnormality (ILA); the histopathological and CT findings of these conditions reflect the required multidisciplinary team approach, involving pulmonologists, radiologists, and pathologists, for their diagnosis and management. Concomitantly, traction bronchiectasis and bronchiolectasis have been recognized as the most persistent and important indices of the severity and prognosis of fibrotic lung diseases. The traction bronchiectasis index (TBI) can stratify the prognoses of patients with ILAs. In this review, the evolutionary concepts of UIP, NSIP, and ILAs are summarized in tables and figures, with a demonstration of the correlation between CT findings and pathologic evaluation. The CT-based UIP score is being proposed to facilitate a better understanding of the spectrum of pulmonary fibrosis, from ILAs to UIP, with emphasis on traction bronchiectasis/bronchiolectasis.

Invasive fungal infection (IFI) is a serious threat to pediatric patients with cancer given high morbidity and mortality. We present an 18-year-old male with precursor T-cell lymphoblastic leukemia who developed Pancoast syndrome, presented with paresthesia and numbness in the right shoulder and arm during a neutropenic fever period. He was diagnosed with pneumonia in the right upper lung field. He was later found to have an invasive pulmonary fungal infection caused by multiple fungi species, including Rhizomucor, confirmed by histology and polymerase chain reaction (PCR) (proven infection), Penicillium decumbens diagnosed by PCR, and Aspergillus suspected from galactomannan assay (probable infection). Unfortunately, the patient's condition further worsened owing to the aggravation of leukemia, chemotherapy-induced neutropenia, and bacterial coinfection, leading to multiorgan failure and death. Here, we report a case of IFI caused by multiple fungal species that presented as Pancoast syndrome.