Clinical features of organizing pneumonia in anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorders.

BACKGROUND: Anti-aquaporin-4 (AQP4) antibody is an autoantibody marker often observed in patients with neuromyelitis optica spectrum disorder (NMOSD). The pathological relevance of complicated pulmonary disorders in anti-AQP4 antibody-positive NMOSD remains unclear. We aimed to assess the clinical and histological relevance of complicated pulmonary disorders in anti-AQP4 antibody-positive NMOSD. METHODS: We retrospectively reviewed the medical records of 52 patients with anti-AQP4 antibody-positive NMOSD and conducted immunohistochemical evaluations of the lung biopsy specimens. RESULTS: Among 52 patients with anti-AQP4 antibody-positive NMOSD, 4 patients showed pulmonary involvement with a diagnosis of organizing pneumonia (OP). The proportion of males was larger (75% vs. 12.5%; p = 0.013) and creatine kinase levels were higher (458.3 U/L vs. 83.9 U/L; p = 0.003) in patients with OP than in those without OP. OP development preceded or coincided with the NMOSD symptoms. Chest computed tomography findings were consistent with OP in all four patients. Bronchoalveolar lavage fluid predominantly contained lymphocytes. Transbronchial lung biopsy revealed intraluminal plugs of inflammatory debris within the alveoli. Alveolar epithelial cells covering the OP lesions exhibited AQP4 loss, immunoglobulin G deposition, and complement activation. Corticosteroid treatment resulted in clinical improvement of OP. CONCLUSION: OP may be considered a pulmonary manifestation of anti-AQP4 antibody-positive NMOSD beyond the central nervous system. Complement-dependent cytotoxicity of the lung epithelial cells caused by anti-AQP4 antibody is at least partly involved in OP development. When diagnosing NMOSD, the possibility of OP should be carefully evaluated based on the detailed history and chest imaging findings.

Pancreatic tuberculosis in an immunocompetent young female mimicking a malignant tumor: A case report and diagnostic radiological investigation.

Tuberculosis remains the leading cause of infectious disease related death worldwide with extrapulmonary tuberculosis being particularly difficult to diagnose. Here, we report a case of pancreatic tuberculosis (PTB) in an immunocompetent young female, which mimicked a malignant tumor diagnosed by endoscopic ultrasound-guided fine needle aspiration and biopsy (EUS-FNAB). A 19-year-old Japanese female with no prior medical history presented with abdominal epigastralgia and appetite loss lasting 2 months. A solid lobular mass was observed in the pancreatic head with enhanced abdominal computed tomography and magnetic resonance imaging suggested it was a malignant pancreatic tumor. Using EUS-FNAB, granulomas with caseous necrosis and acid-fast bacilli were observed. Polymerase chain reaction results were positive for Mycobacterium tuberculosis but negative for Mycobacterium avium complex. Therefore, the patient was diagnosed with PTB. Her symptoms and radiological findings improved with a standard antituberculosis therapy. PTB is difficult to differentiate from other pancreatic diseases with Magnetic resonance imaging (MRI) patterns of T1, T2 weighted, or diffusion-weighted image (DWI) images. To investigate novel radiological diagnostics for PTB, we focused on MRI apparent diffusion coefficient (ADC) values, which have not been investigated in this context. The present case showed 0.52 × 10-3 mm2/s; additionally, the mean value of other mass-forming pancreatic diseases, such as pancreatic cancer was 1.592 × 10-3 mm2/s (the range: 1.015-3.025 × 10-3 mm2/s). The range does not overlap with the present PTB case or other pancreatic diseases. Therefore, ADC values may be useful as a noninvasive radiological diagnostic method for PTB.

Remitting Seronegative Symmetrical Synovitis with Pitting Edema Syndrome Complicated with Organizing Pneumonia.

We herein report a 62-year-old man with idiopathic pulmonary fibrosis who developed remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome during follow-up. Pulmonary infiltrations were detected concomitantly with the development of RS3PE syndrome, and prednisolone improved both the pulmonary and extrapulmonary lesions. Recognizing the pulmonary manifestations of RS3PE syndrome is necessary to provide an appropriate diagnosis and disease management.

Diffuse alveolar hemorrhage caused by IgA deposition associated with multiple myeloma.

We report a man with diffuse alveolar hemorrhage caused by multiple myeloma who was diagnosed with the aid of bronchoalveolar lavage and transbronchial lung biopsy. Multiple myeloma should be considered as an important differential diagnosis in patients with diffuse alveolar hemorrhage, and bronchoscopy may help to differentiate the cause.