Clinicopathological features of minute meningothelial-like nodules in the lung / 中华病理学杂志

ABSTRACT

Objective@#To study the clinicopathological features of minute meningothelial-like nodule (MMLN) in the lung and its histological origin.@*Methods@#Clinicopathological data of 93 patients diagnosed with MMLN in Jiangsu Province Hospital(the First Affiliated Hospital of Nanjing Medical University) from September 2016 to September 2018 were collected and analyzed retrospectively, and the related literature was reviewed.@*Results@#Ninety-three MMLNs were identified from 5 239 patients undergoing pulmonary resection. There were 18(19.6%) males and 75(80.6%) females; age ranged 38-81 years, with mean age 58 years. The frequency of MMLNs was related to the site of origin, and single lesion most commonly (43%) arose in right lobe. There was no significant relationship with patients′ age, gender and the co-existing malignant tumors. Receiver operating characteristic (ROC) curve analysis showed that the area under curve (AUC) was 0.584 (P<0.05), and the best cut-off point was 11.5, indicating an appropriate increase in the number of slides to at least 12 would facilitate the discovery of MMLN. Histologically, MMLN cells showed bland morphology, located around the normal alveolar cavity or form nests or whorls centered on small veins. Immunohistochemistry was done in 55 cases, and all cells expressed vimentin; and a high proportion of cells expressed EMA, PR, CD56 and Calponin. They were all negative for TTF1, Syn, CgA, CKpan, SMA and CD34. The Ki-67 index was low in all cases (<2%). In addition odds ratio analysis showed that MMLN was not a risk factor for invasive carcinoma (including other malignant tumors in the lung, P=0.100).@*Conclusions@#MMLN closely resembles meningothelioma morphologically and immunophenotypically, although its origin remains uncertain. In the study, MMLN is considered as a reactive benign lesion around pulmonary pathology, functioning as an effector regulating small blood vessels caliber. MMLN probably provides nutritional support to the surrounding disease and affords a suitable environment for the development of tumor cells.