A Case of Lung Cancer Associated with Minute Pulmonary Meningothelial-like Nodules: Risk for Misstaging Intraoperatively

Abstract

Minute pulmonary meningothelial-like nodules (MPMNs) are rare lesions of the pulmonary interstitium. They comprise small nests of monomorphic round to spindle cells, likely reactive in nature. Although multiple lesions with unilateral involvement of one or even all lobes of the same lung have been described, they are most often single and their average size is 1-3 mm in diameter. Computed tomography (CT) scan did not contribute to the detection of these small pulmonary lesions. These nodules are generally asymptomatic and are usually found incidentally at autopsy or in surgical specimens resected for unrelated causes. Here, we report a patient with solitary pulmonary nodule receiving lobectomy. Intraoperatively, the surgeon found a grey white firm tumor about 1.6×1.2×1 cm in size and tour tiny firm satellite nodules in the same lobe. Because of different AJCC pathological stage, it is necessary to examine whether the tumor nodules in the same lobe are separate or not. The intraoperative frozen sections reported adcnocarcinoma for the largest one and benign for the other four smaller nodules. The final diagnosis is moderately differentiated adenocarcinoma of lung with pulmonary meningothelial-like nodules. The AJCC pathological staging is pT1aN0M0. stage IA, and mis-staging as stage IIB has been avoided.