To analyze the clinical characteristics and CT manifestations of pulmonary cryptococcosis (PC) with nodule and mass, and to explore its characteristic signs, so as to improve the diagnostic accuracy of PC.

The clinical and imaging data of 18 cases of pulmonary cryptococcosis with nodal mass confirmed in our hospital from August 2011 to January 2020 were analyzed retrospectively, including 13 cases confirmed by operation and pathology, 5 cases confirmed by puncture pathology. 18 cases had complete clinical data, and all completed CT plain scan, 5 cases completed CT enhanced scan. The CT imaging features of patients were analyzed, including the number, shape, size, distribution, density and enhancement of lesions.

None of the 18 patients had a clear history of pigeon fecal contact, and all of them were HIV negative. 14 cases had normal immune function, 4 cases had low immune function, 3 cases had type 2 diabetes, 1 case had lung cancer for one year. 11 patients had no clinical symptoms, but they were found by chance in physical examination, 2 patients were treated with cough, 1 patient with chest distress for one year. Four patients with hypoimmunity were found by routine lung CT. There were 11 males and 7 females. The age of onset was from 27 to 79 years old, with an average age of (45.9±12.6)years. There were 11 cases of right lung and 7 cases of left lung. There were 15 cases of single nodule type and 3 cases of multiple nodule type. The lesions were mainly subpleural distribution, the size was within 2.5 cm, halo sign was seen in 13 cases, bronchi inflation sign was seen in 10 cases, nodular fusion was seen in multiple cases, and mushroom brothers sign was seen in 1 case. CT enhanced scan showed that all the nodules showed mild to moderate delayed enhancement.

PC is more common in young and middle-aged men, with mild clinical symptoms, and more common in the right lung. PC tends to be distributed in the lung field and under the pleura. CT manifestations such as halo sign, bronchi inflation sign and mushroom brothers sign have certain characteristics.