The histopathological diagnosis of mycobacterial infection may be improved by a comprehensive analysis using artificial intelligence. Two autopsy cases of pulmonary tuberculosis, and forty biopsy cases of undetected acid-fast bacilli (AFB) were used to train AI (convolutional neural network), and construct an AI to support AFB detection. Forty-two patients underwent bronchoscopy, and were evaluated using AI-supported pathology to detect AFB. The AI-supported pathology diagnosis was compared with bacteriology diagnosis from bronchial lavage fluid and the final definitive diagnosis of mycobacteriosis. Among the 16 patients with mycobacteriosis, bacteriology was positive in 9 patients (56%). Two patients (13%) were positive for AFB without AI assistance, whereas AI-supported pathology identified eleven positive patients (69%). When limited to tuberculosis, AI-supported pathology had significantly higher sensitivity compared with bacteriology (86% vs. 29%, p = 0.046). Seven patients diagnosed with mycobacteriosis had no consolidation or cavitary shadows in computed tomography; the sensitivity of bacteriology and AI-supported pathology was 29% and 86%, respectively (p = 0.046). The specificity of AI-supported pathology was 100% in this study. AI-supported pathology may be more sensitive than bacteriological tests for detecting AFB in samples collected via bronchoscopy.

Background: Chronic beryllium disease (CBD) is a granulomatous disease that resembles sarcoidosis but is caused by beryllium. Clinical manifestations similar to those observed in CBD have occasionally been reported in exposure to dusts of other metals. However, reports describing the clinical, radiographic, and pathological findings in conditions other than beryllium-induced granulomatous lung diseases, and detailed information on mineralogical analyses of metal dusts, are limited. Case presentation: A 51-year-old Japanese man with rapidly progressing nodular shadows on chest radiography, and a 10-year occupation history of underground construction without beryllium exposure, was referred to our hospital. High-resolution computed tomography showed well-defined multiple centrilobular and perilobular nodules, and thickening of the intralobular septa in the middle and lower zones of both lungs. No extrathoracic manifestations were observed. Pathologically, the lung specimens showed 5–12 mm nodules with dust deposition and several non-necrotizing granulomas along the lymphatic routes. X-ray analytical electron microscopy of the same specimens revealed aluminum, iron, titanium, and silica deposition in the lung tissues. The patient stopped smoking and changed his occupation to avoid further dust exposure; the chest radiography shadows decreased 5 years later. Conclusion: The radiological appearances of CBD and sarcoidosis are similar, although mediastinal or hilar lymphadenopathy is less common in CBD and is usually seen in the presence of parenchymal opacities. Extrathoracic manifestations are also rare. Despite limited evidence, these findings are similar to those observed in pneumoconiosis with a sarcoid-like reaction due to exposure to dust other than of beryllium. Aluminum is frequently detected in patients with pneumoconiosis with a sarcoid-like reaction and is listed as an inorganic agent in the etiology of sarcoidosis. It was also detected in our patient and may have contributed to the etiology. Additionally, our case suggests that cessation of dust exposure may contribute to improvement under the aforementioned conditions.

Sarcoidosis is a systemic inflammatory disease characterized by noncaseating epithelioid cell granulomas. However, certain infections can exhibit similar histological findings. We present a case of a 69-year-old man who was initially diagnosed with sarcoidosis and later was confirmed, through 16S rRNA sequencing, to have disseminated Mycobacterium genavense infection. Acid-fast bacteria were detected in the bone marrow biopsy using Ziehl–Neelsen staining, but routine clinical tests did not provide a definitive diagnosis. The patient tested negative for HIV, anti-interferon-gamma antibodies, and genetic immunodeficiency disorders. He was treated with multiple drugs, including aminoglycosides and macrolides, but showed no improvement in fever and pancytopenia. However, these clinical signs responded favorably to steroid therapy. We reviewed 17 Japanese cases of M. genavense infection. All cases were in males; 7/17 (41%) were HIV-negative; and 12/17 (71%) had a decreased CD4 count. Genetic analysis confirmed M. genavense isolation, and macrolides were used universally. Mycobacterium genavense infection is challenging to identify and mimics other systemic inflammatory diseases such as sarcoidosis. There are no standard treatment protocols. Our case report and Japanese case review contribute to understanding this rare disease.

Primary ciliary dyskinesia (PCD) is a genetic and congenital disease associated with an abnormal ciliary ultrastructure and function and is estimated to affect 1 in 15,000–20,000 individuals. A PCD diagnosis can be achieved by genotyping. Here, we performed whole-exome analysis for the diagnosis of PCD and described the detailed clinical characteristics of the case. A 39-year-old Japanese woman with sinusitis and bronchiectasis without situs inversus had had upper and lower respiratory symptoms since childhood and had received long-term macrolide therapy without an accurate diagnosis. A moderate deterioration of cilia function was observed by high-speed video microscopy analysis; additionally, the number of cells with moving cilia was fewer than that in patients without PCD. Electron microscopy revealed no apparent structural abnormalities. We performed whole-exome analysis and identified novel biallelic variants of SPEF2 in the homozygous state (c.1860_1861insCT). We confirmed the absence of SPEF2 protein expression in the cilia of the nasal mucosa using fluorescent immunostaining. Accordingly, she was diagnosed as having PCD with the SPEF2 variant. The present case suggests that the deterioration of cilia function is moderate, the number of respiratory cells with moving cilia might be reduced, and the respiratory condition could be severe in patients with PCD with the SPEF2 variant.

Objectives: to evaluate the number of cases of idiopathic pulmonary fibrosis (IPF) that included histological features of connective tissue disease (CTD) and to check whether they demonstrated the clinical features of CTD, using a previously reported CTD-interstitial pneumonia (IP) index that histologically differentiates CTD-associated and idiopathic IP. Methods: patients diagnosed with IPF following video-assisted thoracoscopic biopsy through multidisciplinary team diagnosis between 2014 and 2017 were selected. Pathological observation was made by four pathologists who scored eight observational items needed for the CTD-IP index. Cases determined as CTD, by the CTD-IP index, were extracted, and their clinical features were compared. Results: a total of 94 cases of IPF were identified, of which 20 were classified into the CTD group using the CTD-IP index with reasonable interobserver agreement (k = 0.76). Cases pathologically classified into the CTD group were significantly associated with female sex, non-smoking history, autoantibody positivity, and CTD symptoms (p = 0.01, 0.03, 0.01, and 0.04, respectively). Conclusions: patients with IPF with pathological findings of CTD showed clinical characteristics similar to those of patients with CTD.