Although inhalation therapy is an important and basic treatment for respiratory tract diseases, little scientific analysis has been conducted regarding the inhalation method, and there are few statements in the guidelines. Based on the results of the aerosolization rate, particle size distribution, and aerosol spray velocities of pMDI analyzed so far, as well as the aerosolization rate, particle size distribution, and inspiratory resistance of DPI, for the standard inhalation method, I recommend that users exhale slowly and deeply, and then take a deep breath in a few seconds corresponding to the vital capacity (L), that is an inspiratory flow rate of around 1 L/sec (=60 L/ min), and finally hold their breath for a few seconds.

A 53-year-old woman originally from China was referred to our hospital because of a cough, pleural effusion, and eosinophilia. Detailed history-taking revealed the consumption of a homemade Chinese traditional dish, “Drunken Crab.” She purchased the crabs, which were Eriocheir japonica caught in Japan, on the Internet and pickled them at home with soy sauce and Chinese liquor. The Paragonimus egg was identified in her sputum. Enzyme-linked immunosorbent assay revealed high titers of P. westermani-specific immunoglobulin G antibodies in serum and pleural effusion. Praziquantel administration for three days improved the symptoms and pleural effusion. Since the number of immigrant patients is increasing, it is important to be aware of infectious diseases due to differences in dietary habits.

We report a case of disseminated cryptococcosis presenting with miliary opacities in a patient receiving immunosuppressive therapy for interstitial pneumonia. An 83-year-old woman, undergoing treatment with prednisolone and azathioprine for interstitial pneumonia, was diagnosed with disseminated cryptococcosis after Cryptococcus was detected in her urine and blood, and chest computed tomography revealed miliary opacities. Despite antifungal treatment, her condition gradually deteriorated, and she died one and a half months later. A pathological autopsy confirmed findings consistent with disseminated cryptococcosis. Although rare, disseminated cryptococcosis can present with miliary opacities on chest computed tomography scans in patients with compromised cellular immunity. Clinicians should be aware of this possibility and conduct thorough investigations when encountering similar radiological findings.

Anti-PM-Scl antibody-positive interstitial lung disease (ILD) presents with diverse clinical manifestations. We report three cases with different clinical courses and imaging findings. The first case involved slowly progressive ILD with muscle symptoms, the second case was a rapidly progressive ILD without muscle symptoms, and the third case was a subacute ILD with both muscle and skin symptoms. Considering the heterogeneity of clinical presentations and imaging findings, testing for anti-PM-Scl antibodies is clinically significant in ILD patients with unclear diagnoses but features suggestive of collagen vascular disease.

A 73-year-old woman was diagnosed with oral lichen planus at a previous hospital around three years prior and had been receiving pharmacological treatment. However, her symptoms did not improve, and she developed shortness of breath, prompting her to visit our hospital. She tested positive for SARS-CoV-2 on polymerase chain reaction assay, and chest computed tomography revealed bilateral ground-glass opacities and an anterior mediastinal tumor. A blood test revealed hypogammaglobulinemia. Her COVID-19 symptoms improved with immunoglobulin replacement therapy and supportive care. Subsequently, she underwent video-assisted thoracoscopic thymectomy, and histopathological examination confirmed a type AB thymoma. Given the presence of concomitant hypogammaglobulinemia, she was diagnosed with Good’s syndrome.

A 68-year-old Japanese man visited our hospital because tumor shadows were detected in his lungs. Chest contrast-enhanced computed tomography revealed irregular solid masses: one measuring 40 mm in the center of the lateral segment of the right middle lung lobe (S⁴) and the other measuring 19 mm in the apicoposterior segment of the left upper lung lobe (S¹⁺²). Since bronchoscopic biopsy of the right lung tumor failed twice to yield a definitive diagnosis, surgical biopsy was performed. The histopathological findings of the resected specimens showed marked fibrosis, lymphoplasmacytic infiltration, immunoglobulin G4 (IgG4)-positive cell infiltration, and obliterative phlebitis in the background of the destroyed alveolar structure. IgG4-related respiratory disease (IgG4-RRD) was diagnosed on the basis of the diagnostic criteria for IgG4-RRD. Anemia progressed in the early postoperative period, with hemoglobin levels reaching 4.9 mg/dL. Autoimmune hemolytic anemia (AIHA) was diagnosed after detailed examinations, and steroid therapy at 50 mg/day was initiated, following which the anemia was observed to improve. Simultaneously, the tumor shadows in both lungs also decreased in size. The steroid dose was tapered to 1 mg/day, and the patient currently continues to be in treatment. We report the clinical course of this rare case along with a literature review.

Epipericardial fat necrosis (EFN) is a rare disease that presents with acute pleuritic pain. EFN is generally associated with a mildly elevated inflammatory response, and nodules are often present. Herein, we describe a case of EFN diagnosed with acute pleuritic pain, high inflammatory response, mediastinal mass shadow, and pleural effusion. Although pericardial fat necrosis is considered to be a rare disease, an increasing number of cases have been reported in recent years. EFN should be considered in patients with acute pleuritic pain even if they present with other symptoms such as mediastinal mass and high inflammatory response.

We encountered a 65-year-old man who had been referred to our hospital because of a mass shadow in the right upper lung field. Computed tomography (CT) showed a 72 mm mass extending along the anterior chest wall in the right upper lobe. CT-guided biopsy revealed a malignant tumor. No definitive diagnosis could be reached, although several pathologists examined the case. To confirm the diagnosis, a thoracoscopic lung biopsy was performed under general anesthesia. We finally diagnosed his illness as localized sarcomatoid pleural mesothelioma. He was started on a combination therapy with nivolumab and ipilimumab. In patients with a history of asbestos exposure, localized pleural mesothelioma should be kept in mind even if the lesion is a mass.

A 72-year-old male was diagnosed with advanced gastric cancer. After receiving four cycles of combination chemotherapy with S-1, oxaliplatin, and nivolumab, he suffered from dyspnea. He was admitted to our hospital due to consolidation of the bilateral lower lobes on chest computed tomography. We diagnosed drug-induced lung injury due to nivolumab as an immune-related adverse event. Steroid pulse therapy was effective, but his condition became worse after reduction of the corticosteroid dose. Two cycles of infliximab therapy successfully alleviated the lung injury. The addition of infliximab to corticosteroids may be effective for refractory drug-induced lung injury caused by immune checkpoint inhibitors.

Herein, we present a female case of sarcoidosis that developed after treatment for malignant lymphoma and exacerbated after recurrence of malignant lymphoma. A 49-year-old female was admitted to our hospital because of abnormal chest imaging findings. She had been diagnosed with diffuse large B-cell lymphoma 66 months before the admission. Thirteen months after the completion of the treatment, she developed sarcoidosis, and lymphoma was found to have recurred 18 months before the admission. One month before, FDG-PET had revealed diffuse fine nodules in the bilateral lung fields as well as enlargement of both hilar and mediastinal lymph nodes. We performed a bone marrow biopsy, bronchoscopy, and liver biopsy. Anti-Propionibacterium acnes monoclonal antibody (PAB antibody) staining was performed on each specimen, and PAB antibody-positive cells were detected in the epithelioid cell granulomas compatible with sarcoidosis. Therefore, physicians should be aware that on rare occasions exacerbation of sarcoidosis occurs after the recurrence of malignant lymphoma.

A 62-year-old woman was referred to our department for further investigation after a chest computed tomography scan, performed during an evaluation for a persistent cough, had revealed multiple small granular shadows in the lungs. Blood tests confirmed a positive result on interferon-gamma release assay, but sputum acid-fast bacillus tests were negative. Follow-up imaging showed no significant changes in the lung shadows, so we performed a surgical lung biopsy. The biopsy specimens showed no findings suggestive of pulmonary tuberculosis, and the patient was pathologically diagnosed with minute pulmonary meningothelial-like nodules.