Minute pulmonary meningothelial-like nodules: associations between computed tomography and pathology features.

Background: Increased use of multislice computed tomography (CT) scans has revealed that minute pulmonary meningothelial-like nodules (MPMNs) showed as ground-glass nodules (GGNs) are frequent in patients. However, little is known about the incidence and fate of nodules. By using a cross-sectional design, this study compared the multislice CT signs and pathological results of MPMNs, and further used pathological results to explain the formation mechanism of the CT signs of MPMNs to improve the clinical understanding of the disease.

Methods: The clinicopathological data of 93 cases diagnosed as MPMNs in the Jiangsu Province Hospital from January 2016 to September 2019 and the Nanjing First Hospital from January 2017 to December 2019 were examined. The related literature was reviewed, and each case's age, gender, medical history, and preoperative CT examinations were classified. Based on CT signs, this study analyzed the imaging features, including size, shape, boundary, distribution, opacity, and their relationship with pulmonary blood vessels.

Results: A total of 13 cases had immunohistochemistry results among which the lesions showed consistent positive expression of vimentin (100%), followed by epithelial cell membrane antigen (92.3%) and progesterone (8%). The MPMNs mainly occurred in individuals aged 50-59 years (32.6%). Most patients (82.6%) had neoplastic disease. All nodules (100%) manifested with a round shape and well-demarcated borders on images. The size of the nodules on CT scans ranged from 2.5 to 5.0 mm, with an average size of 3.04±1.12 mm. Most nodules were subpleural (89.1%) and showed ground-glass opacity (97.8%). The follow-up results of postoperative clinical manifestations and chest CT examination were negative in 12 patients.

Conclusions: This study suggested that the pathological findings of MPMNs could explain the formation mechanism of the CT signs. The results can provide guidance for the diagnosis of the disease in the future.