Abstract: Pulmonary cryptococcosis is one of the most common pulmonary fungal infections. It lacks clinical and imaging specificity and is easy to be misdiagnosed and missed. The diagnosis of pulmonary cryptococcosis mostly depends on etiology and histopathology. The metagenomic next-generation sequencing technology that has emerged in recent years provides new ideas for the early and rapid diagnosis and treatment of infectious diseases. This article reports the clinical characteristics and the process of diagnosis and treatment of 2 cases of pulmonary cryptococcosis patients, with no previous immunocompromised diseases and no complaining of respiratory symptoms. Physical examination found no obvious signs, chest computed tomography (CT) scan showed a round solid nodules in the outer area of the lung field. They were finally diagnosed rapidly by the the metagenomic next-generation sequencing(mNGS) technology of bronchoalveolar lavage fluid and received treatment on time.

Key words: pulmonary cryptococcosis, bronchoalveolar lavage fluid(BALF), metagenomic next-generation sequencing(mNGS)