Minute Pulmonary Meningothelial-like Nodules : A Case Report

Minute pulmonary meningothelial-like nodules (MPMNs) are traditionally identified incidentally as solitary or multiple nodules with a size of 0.1-3 mm in autopsied or resected lungs. Recently, there have been several reports of MPMNs identified as ground-glass nodules (GGNs) on computed tomography (CT), leading to surgical intervention. Here, we present a case of MPMN with a brief overview of the literature. A 73-year-old female patient underwent CT for the evaluation of aspergilloma, and multiple GGNs were identified in the lower lobes of both lungs. One of the GGNs, as well as the aspergilloma, was resected for pathological examination and was subsequently diagnosed as MPMN. Differential diagnoses for multiple GGNs include atypical adenomatous hyperplasia, multifocal micronodular pneumocyte hyperplasia, and metastatic lung tumors. In MPMN, GGNs exhibiting ring-like structures with a central lucency are sometimes observed, which may be a characteristic feature to differentiate MPMN from other diseases.