Unique Distribution of Minute Meningothelioid Nodules at The Alveolar Mouths of Peripheral Airways within the identical lung harboring Adenocarcinoma

Abstract

Minute meningothelioid nodules (MMNs) are not rare lesions in the lungs; however, their specific origin and functions remain unknown. In a previous study, among 81 cases of resected lungs, MMNs were detected in 69 out of 500 surgical biopsies (13.8%) and 12 out of 25 lobectomies (48%) via detailed histochemical examination, with a female predominance at an average age of 62, and only 4 out of 81 cases involved patients younger than 40 years. These findings indicate that MMNs are not congenital in origin. In another report, MMNs were detected in 121 out of 1724 resected lungs (7%) via pathologic examination, with a female predominance. Here, we investigated a pulmonary adenocarcinoma case with unique distribution of MMNs at the alveolar mouths (AMs) of lungs. To the best of our knowledge, such a case has not yet been described even in a report on more than 100 cases of MMNs.