Granulomatosis with polyangiitis (GPA) is a rare ANCA-associated necrotizing vasculitis that predominantly affects the respiratory tract and kidneys. Gastrointestinal involvement is uncommon, and pancreatic manifestations are exceedingly rare. Diffuse alveolar hemorrhage (DAH) represents a severe and potentially fatal complication. We report a 44-year-old male who was initially diagnosed with a pancreatic mass suspicious for malignancy and planned for pancreatectomy. During hospitalization, he developed acute respiratory distress with hemoptysis. Imaging revealed diffuse ground-glass opacities consistent with DAH and a bulky pancreatic tail lesion. Laboratory investigations demonstrated severe anemia, urinary abnormalities suggestive of glomerulonephritis, and strongly positive c-ANCA. A diagnosis of granulomatosis with polyangiitis was established based on clinical, radiological, and serological findings. The patient was treated with intravenous methylprednisolone pulse therapy followed by rituximab induction, leading to rapid clinical improvement and stabilization. He remained asymptomatic during follow-up. This case highlights an extremely rare presentation of GPA with pancreatic mass and diffuse alveolar hemorrhage, emphasizing the importance of considering vasculitis in atypical pancreatic lesions with systemic manifestations to enable early diagnosis and appropriate immunosuppressive therapy.

Objective: To understand the etiological diagnosis, triggers for disease recurrence and treatment status of diffuse alveolar hemorrhage (DAH) in Chinese children. Methods: A retrospective cohort study was conducted. Clinical data, including baseline information, laboratory findings, chest imaging findings and treatment regimens were collected from 567 children with DAH admitted to 21 hospitals in China from 2002 to 2021. Cases with immune-related etiologies or undetermined etiological diagnosis were included and divided into two groups based on glucocorticoids treatment duration: ≥3 months group and <3 months group. The study period from January 2002 to December 2021 was divided into two time intervals: 2002-2011 and 2012-2021. The two groups were compared in terms of etiological diagnosis rate, initial and overall immunosuppressant use rate, disease recurrence rate and mortality rate. All group comparisons were performed using the χ[2] test. Results: Among the 567 children with DAH, 333 were male and 234 were female. The age at onset was 4.0 (2.1, 6.5) years and the follow-up duration was 4.4 (2.4, 7.2) years. A definite etiological diagnosis was established in 107 cases (18.9%), while 460 cases (81.1%) remained without a definite etiological diagnosis. Among the 494 cases (including idiopathic pulmonary hemosiderosis and those with undetermined etiological diagnosis), 389 cases (78.7%) were initially treated with glucocorticoids alone and 45 cases (9.1%) with a combination of glucocorticoids and immunosuppressants. Throughout the treatment, immunosuppressants were used in 132 cases (26.7%). Among the 549 cases (including immune-related cases and those with undetermined etiological diagnosis), 303 cases (55.2%) experienced recurrent exacerbation of the disease. The common triggers included respiratory infection in 193 cases (35.2%), glucocorticoid dose reduction in 103 cases (18.8%) and non-adherence to medication in 66 cases (12.0%). Eight cases were lost to follow-up. The mortality rate was 8.7% (47/541), with causes of death including end-stage lung disease with severe infection in 32 cases (5.9%), severe pulmonary hemorrhage in 12 cases (2.2%) and unknown cause in 3 cases (0.5%). Among those receiving glucocorticoids therapy, 373 cases were in the ≥3 months group and 125 cases in the <3 months group. The mortality rate in the ≥3 months group was lower than that in the <3 months group (P<0.01). There were 92 cases in the 2002-2012 group and 457 cases in the 2012-2021 group. The utilization rates of immunosuppressants in both initial treatment and the entire treatment course for children with immune-related and those with undetermined etiological diagnosis were higher in the 2012-2021 group than in the 2002-2012 group (both P<0.01). Conclusions: In China, pediatric DAH has complex etiologies and a definitive etiological diagnosis remains difficult to establish in some cases. Recurrent exacerbation is common and mainly due to the respiratory infection, glucocorticoids dose reduction and non-adherence to medication. Glucocorticoids remain the primary treatment, with combined use of immunosuppressants in some cases.

Usual interstitial pneumonia (UIP) has traditionally been regarded as synonymous with idiopathic pulmonary fibrosis (IPF) in the absence of an identifiable cause. However, emerging evidence demonstrates that a subset of patients with a UIP pattern exhibit myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCAs), suggesting a distinct and evolving clinical phenotype at the intersection of fibrotic lung disease and systemic autoimmunity. This structured narrative review aims to synthesize current evidence regarding the clinical, diagnostic, and therapeutic implications of MPO-ANCA-associated UIP. Preferred Reporting Items for Systematic Reviews and Meta-Analyses-like methodology was employed to identify and select relevant studies from PubMed (MEDLINE) and Google Scholar published between 2020 and 2026. After screening and eligibility assessment, 18 studies were included in the qualitative synthesis. Data were extracted on clinical presentation, radiological features, serological findings, therapeutic strategies, and outcomes. The available evidence indicates that pulmonary fibrosis may precede or coexist with ANCA-associated vasculitis, particularly microscopic polyangiitis, supporting the concept of UIP as a potential early or lung-dominant manifestation of systemic disease. This phenotype is characterized by a dual trajectory, combining progressive fibrosis with the risk of severe vasculitic complications such as diffuse alveolar hemorrhage. Radiological findings alone are insufficient for differentiation, highlighting the importance of MPO-ANCA testing for early phenotyping. Therapeutic management remains challenging due to the lack of standardized guidelines, requiring individualized and multidisciplinary approaches that balance antifibrotic and immunosuppressive strategies. MPO-ANCA-associated UIP should be recognized as a distinct and dynamic clinical entity with significant diagnostic and prognostic implications. Early identification and structured follow-up are essential to optimize outcomes and guide timely therapeutic interventions.

Aspergillus fumigatus is an important opportunistic pathogen. In the immunocompromised people, A. fumigatus infection can cause invasive aspergillosis, which is characterized by high incidence rate and high mortality. However, due to the limited availability of anti-fungal drugs and the continuous emergence of drug-resistant strains, the treatment of A. fumigatus infection is facing enormous challenges. 5-nitro-8-hydroxyquinoline (NQ) is an ancient antibiotic and pharmaceutical intermediate and fungicide, which is not only exhibits good antibacterial activity on against drug-resistant Staphylococcus aureus, Candida spp., but also has good biofilm eradication on activity against Pseudomonas aeruginosa, Acinetobacter baumannii. However, it is not known whether NQ has anti-A. fumigatus infection effects in vivo. This study evaluates the in vitro and in vivo activity of NQ against A. fumigatus. The results showed that NQ not only had a good anti-A. fumigatus effect, but also promoted the phagocytosis and killing ability of alveolar macrophages to A. fumigatus. In addition, we found that intraperitoneal injection of NQ significantly reduced the diffuse infection degree of A. fumigatus and the fungal burden in mice tissues, and increased the secretion of IL-2, IL-6, IL-10 in the blood. NQ exerted a good anti-fungal effect. In summary, these results confirm that NQ may be a potential anti-fungal drug for treating A. fumigatus infection.

Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis that can mimic infection and malignancy, posing a significant diagnostic challenge. We report the case of a 39-year-old male smoker with a strong family history of lung cancer who presented with fever, weight loss, dyspnea, and hemoptysis. Initial evaluation supported infection, with sputum cultures positive for Pseudomonas aeruginosa and Haemophilus influenzae. Imaging later revealed pulmonary masses suspicious for malignancy. The patient subsequently deteriorated with massive hemoptysis and acute kidney injury, requiring ICU admission, mechanical ventilation, blood transfusion, and dialysis. Further investigations demonstrated proteinase 3-ANCA positivity and diffuse alveolar hemorrhage on bronchoalveolar lavage, confirming GPA. Treatment with pulse corticosteroids, IV cyclophosphamide, and plasma exchange resulted in marked clinical recovery. This case underscores the significant diagnostic challenge posed by the overlap between infection, malignancy, and ANCA-associated vasculitis, highlighting the importance of early recognition and timely initiation of immunosuppressive therapy.

Hemoptysis is a potentially life-threatening phenomenon with a wide range of underlying causes. While most episodes are linked to common conditions such as infections, malignancy, or pulmonary embolism, a proportion of cases are due to unusual and often unexpected etiologies. This narrative review summarizes published case reports, series, and observational studies describing rare causes of hemoptysis, including vascular malformations, congenital anomalies, benign tumors, systemic diseases, and unusual infections. These conditions are frequently overlooked, which may delay recognition and appropriate management. The reviewed examples highlight the variety of diagnostic challenges and the broad spectrum of therapeutic strategies that may be required, ranging from endovascular procedures and surgery to targeted medical therapy. Despite advances in diagnostic methods, a subset of patients remain classified as having idiopathic or cryptogenic hemoptysis. For this reason, clinicians should keep a broad differential diagnosis in mind and remain aware of rare but clinically important entities. Awareness of these uncommon presentations and individualized patient management are essential for improving outcomes and avoiding missed critical diagnoses.