Abstract:

Objective The aim of the study is to explore the characteristics of chest CT in patients with HIV-negative pulmonary cryptococcosis (PC) and patients with different immune status. Methods The clinical data and chest CT manifestation of 55 patients with clinical diagnosed HIV-negative PC from January 2012 to August 2018 in the Third affiliated Hospital of Soochow University and the People’s Hospital of Linyi of Shandong Province were collected, including 36 immunocompetent patients and 19 immunocompromised patients. Fifty cases were pathologically diagnosed after biopsy or surgery, one case was diagnosed by bronchoscopic alveolar lavage fluid culture, four cases were diagnosed by cryptococcus capsule polysaccharide antigen latex agglutination test and successful antycryptococcal therapy. The types, characteristics, distribution, accompanying signs of lung lesions and the incidence of imaging signs in immunocompetent patients and immunocompromised patients were analyzed. Results Among the 55 patients, single/multiple pulmonary nodules/masses were the most common (76.4%, 42/55), followed by 10 cases (18.2%) of patchy consolidation, and only 3 cases (5.4%) of mixed type; 39 (70.9%) cases lesions were distributed in a single lobe, of which, 24 (61.5%) were located in the lower lobe; 45 (81.8%) cases were located in the lung periphery; 22 (40.0%) cases were surrounded by satellite foci and ground glass opacity (4 cases, 7.3%), and pleural effusion (2 cases, 3.6%), mediastinal or hilar lymphadenopathy (3 cases, 5.4%) were rare. In 45 cases of nodules/masses, 29 (64.4%) cases were well-defined, 25 (55.6%) cases accompanied with halo sign, 17 (37.8%) cases showed air bronchogram, and 19 (42.2%) cases had spiculation sign, including 4 (21.0%) cases with spinous process and 8 (17.8%) cases with cavity. Among the 29 lesions involving the pleura, 18 (62.1%) were adjacent to the pleural with a wide base. According to the contrast-enhanced CT, 88.2% (15/17) cases were uniformly enhanced, and 76.5% (13/17) were mildly enhanced. Compared with the immunocompromised patients, single nodules/masses were more common (50.0% (18/36) vs. 21.0% (4/19), χ ²=4.342, P=0.037), while the satellite opacities and cavity formation rate were significantly lower (30.6% (11/36) vs. 57.9% (11/19), χ ²=3.873, P=0.049; and 9.4% (3/32) vs. 38.5% (5/13), Fisher’s exact test, P=0.034, respectively) than those in immunocompetent patients. Conclusion Single or multiple pulmonary nodules/masses were the most frequent CT findings in patients with HIV-negative PC. The lesions were more common in the lower lobe and peripheral zone. Halo sign and air bronchogram were more common CT signs. Nodules or masses were more frequently adjacent to the pleural with wide base. Immunocompetent patients were more likely to have a single pulmonary nodules/masses but not satellite opacities and cavity.

Key words: Cryptococcosis, Lung diseases, fungal, Tomography, X-ray computer, Diagnostic imaging, Comparative study