Pulmonary blastoma (PB) is a rare and invasive malignancy of the lungs with a poor prognosis. Although the mainstay treatment of PB is surgery, and radiotherapy and chemotherapy have been reported, no standard therapy exists for patients inoperable in advanced stages. Moreover, little is known about driver mutation status and immunotherapy efficacy. This paper presents a male patient diagnosed with classic biphasic PB using CT-guided lung biopsy pathology and immunohistochemistry. The patient\'s symptoms included cough, chest pain, shortness of breath, hemoptysis, and hypodynamia. The primary focus of this paper is to discuss the impact of anti-PD-1 immunotherapy on PB. The patient experienced progression-free survival (PFS) of over 27 months following sintilimab second-line anti-PD-1 therapy. The patient has currently survived for nearly 40 months with a satisfactory quality of life.

We report a case of inflammatory colitis after SARS-CoV-2 infection in a patient with no additional co-morbidity who died within three weeks of hospitalization. As it is becoming increasingly clear that SARS-CoV-2 infection can cause immunological alterations, we investigated the expression of the inhibitory checkpoint PD-1 and its ligand PD-L1 to explore the potential role of this axis in the break of self-tolerance. The presence of the SARS-CoV-2 virus in colon tissue was demonstrated by qRT-PCR and immunohistochemical localization of the nucleocapsid protein. Expression of lymphocyte markers, PD-1, and PD-L1 in colon tissue was investigated by IHC. SARS-CoV-2-immunoreactive cells were detected both in the ulcerated and non-ulcerated mucosal areas. Compared to healthy tissue, where PD-1 is weakly expressed and PD-L1 is absent, PD-1 and PD-L1 expression appears in the inflamed mucosal tissue, as expected, but was mainly confined to non-ulcerative areas. At the same time, these markers were virtually undetectable in areas of mucosal ulceration. Our data show an alteration of the PD-1/PD-L1 axis and suggest a link between SARS-CoV-2 infection and an aberrant autoinflammatory response due to concomitant breakdown of the PD-1/PD-L1 interaction leading to early death of the patient.