Legionella longbeachae pneumonia: A case report and literature review in Japan.

Herein, we report the case of a 74-year-old man diagnosed with Legionella pneumonia detected by Loop-Mediated Isothermal Amplification (LAMP) method, which was suspected to have been transmitted from the potting soil. Legionella longbeachae was identified in the sputum culture. The patient was intubated and maintained on mechanical ventilation. Antimicrobial therapy with azithromycin was also administered. His symptoms were resolved and he was discharged after 26 days of hospitalization. Legionella longbeachae pneumonia rarely occurs in Japan, and published literature of Legionella longbeachae pneumonia cases in Japan was reviewed. Patients with severe pneumonia exposed to potting soils, but with negative urinary antigen test results, should be examined by LAMP method.

Exacerbation of pulmonary cryptococcosis associated with enhancement of Th2 response in the postpartum period.

Cryptococcosis is an invasive mycosis that has become increasingly prevalent in immunocompromised patients. Pregnant women are also one of the risk populations for cryptococcosis. Reversal of Th2 to Th1 response following resolution of immunosuppression during the postpartum period can lead to overt clinical manifestations of a previously silent infection, resembling an immune reconstitution inflammatory syndrome. Here, we report a case of a 30-year-old woman who had an exacerbation of pulmonary cryptococcosis in the postpartum period mimicking an immune reconstitution inflammatory syndrome. In the present case, chest computed tomography showed multiple small nodules on the day of the delivery; however, pulmonary cryptococcosis, which was subclinical during pregnancy, rapidly worsened to mass-like consolidation at one month after the delivery. Pathohistological examination of the lung specimen showed lung parenchyma infiltration with histiocytes and numerous lymphocytes without granulomatous formations, and a small number of yeast-like organisms consistent with Cryptococcus without capillary involvement. Immunohistochemical staining showed predominance of CD3+ cells and CD4+ cells over CD8+ cells. In addition, GATA3+ cells dominated over T-bet + cells. These data suggested exacerbation of pulmonary cryptococcosis associated with enhancement of Th2 response in the postpartum period.

Occult lung metastases of papillary thyroid cancer detected in a resected pulmonary arteriovenous malformation specimen.

A 41-year-old man with exertional dyspnea was referred to our hospital. Chest computed tomography (CT) showed a pulmonary arteriovenous malformation (PAVM) in the left lingular lobe, and magnetic resonance imaging showed a brain abscess. After antimicrobial therapy, the patient underwent thoracoscopic lingulectomy of the PAVM. Pathological examination revealed lung metastases of papillary thyroid cancer (PTC) that were undetectable by CT. The patient underwent total thyroidectomy and D2b lymphadenectomy for the PTC (the pathological stage was T1bN2M1, Stage II). After surgery, the patient received 100 mCi of 131Iodine; post-treatment scans revealed only neck (remnant) uptake and the patient continued with thyroid hormone replacement therapy. To the best of our knowledge, this is the first report of a case of combined PAVM and occult lung metastases of PTC. Clinicians should remember that they may detect micro lung metastases of any cancer when investigating resected lung specimens.

Successful treatment of critical coronavirus disease 2019 in a patient with lung cancer concomitant with pembrolizumab-induced arthritis by methylprednisolone, baricitinib, and remdesivir.

COVID-19 in cancer patients on immunosuppressive agents for the treatment of immune-related adverse events of immune checkpoint inhibitors can rapidly deteriorate. The combination therapy with methylprednisolone, baricitinib, and remdesivir may be effective for critical COVID-19, and further clinical trials are warranted.

Successful Treatment of Non-small-cell Lung Cancer with Atezolizumab Following Tubulointerstitial Nephritis Due to Pembrolizumab.

We herein report a 75-year-old man with non-small-cell lung cancer who developed tubulointerstitial nephritis due to pembrolizumab administration. He was successfully treated with atezolizumab following steroid administration. He was initially diagnosed with lung adenocarcinoma (T1bN3M1b, stage IV), with a programmed cell death-ligand 1 tumor proportion score of 25-49%. Although the tumor responded well to pembrolizumab, the drug was discontinued because of the diagnosis of tubulointerstitial nephritis on a renal biopsy. Tubulointerstitial nephritis was treated with 30 mg prednisolone, the dose of which was tapered to and maintained at 5 mg. Following lung cancer progression, atezolizumab was administered, and the tumor responded again. Its efficacy has been sustained for >15 months without recurrence of tubulointerstitial nephritis.