Ionescu Diana N, Sasatomi Eizaburo, Aldeeb Dalal, Omalu Bennet I, Finkelstein Sydney D, Swalsky Patricia A, Yousem Samuel A
Department of Pathology, Division of Anatomic Pathology, University of Pittsburgh Medical Center, Presbyterian University Hospital, Room A610, 200 Lothrop St., Pittsburgh, PA 15213, USA.
Am J Surg Pathol. 2004 Feb;28(2):207-14. doi: 10.1097/00000478-200402000-00008.
Minute pulmonary meningothelial-like nodules (MPMNs) are incidental interstitial pulmonary nodules. They share histologic, ultrastructural, and immunohistochemical features with meningiomas (MGs).
Sixteen cases yielding 33 separate MPMNs and 10 cases of benign MG were studied. Immunohistochemical studies and mutational analyses were performed on microdissected tissue using 20 polymorphic microsatellite markers targeting 11 genomic regions in an effort to identify genetic similarities of MPMN and MG.
A total of 96.6% of MPMNs stained positive for vimentin, 33.3% for epithelial membrane antigen, 3% for S-100, and all were negative for cytokeratin and synaptophysin. Loss of heterozygosity (LOH) was identified in 25% of single MPMN affecting 3 genomic loci. No solitary MPMN had more than 1 LOH event. Multiple LOHs were seen only in MPMN-omatosis syndrome, where 33.3% of MPMNs showed LOH affecting 7 genomic loci. MG showed the highest frequency of LOH with major events seen at 22q (60%), 14q (42.8%), and 1p (44.4%) that were not shared by MPMN.
Isolated MPMN lacks mutational damage, consistent with a reactive origin. MPMN-omatosis syndrome might represent the transition between a reactive and neoplastic proliferation. MPMNs are different from MG based on the major molecular genetic events seen in their formation and progression.
微小肺脑膜上皮样结节（MPMNs）是偶然发现的间质性肺结节。它们在组织学、超微结构和免疫组化特征上与脑膜瘤（MGs）相似。
对16例产生33个独立MPMNs的病例和10例良性MG病例进行研究。使用针对11个基因组区域的20个多态性微卫星标记对显微切割组织进行免疫组化研究和突变分析，以确定MPMN和MG的遗传相似性。
总共96.6%的MPMNs波形蛋白染色阳性，33.3%上皮膜抗原染色阳性，3% S-100染色阳性，所有病例细胞角蛋白和突触素染色均为阴性。在单个MPMN中，25%发现杂合性缺失（LOH），影响3个基因组位点。没有单个MPMN有超过1次LOH事件。仅在MPMN瘤病综合征中观察到多个LOH，其中33.3%的MPMNs显示LOH影响7个基因组位点。MG显示出最高的LOH频率，主要事件发生在22q（60%）、14q（42.8%）和1p（44.4%），这些位点MPMN未共享。
孤立的MPMN缺乏突变损伤，符合反应性起源。MPMN瘤病综合征可能代表反应性增殖和肿瘤性增殖之间的转变。基于MPMN形成和进展过程中观察到的主要分子遗传学事件，MPMN与MG不同。
