Validation of a minimal panel of antibodies for the diagnosis of malignant pleural mesothelioma

SummaryAimsWe previously established the use of a minimal panel of antibodies as sufficient to diagnose most epithelial malignant mesothelioma (MPM). We aimed to validate this approach and investigate the utility of a D2-40 antibody.MethodsA series of 80 MPM patients selected for surgery and 21 consecutive patients with pleural metastatic carcinoma were included. A minimal panel of antibodies, consisting of calretinin, BG8 and CD15, and D2-40 was investigated.ResultsTherewere61 epithelial and 19 biphasic MPM as well as 12 metastatic lung, six breast (5 ductal adenocarcinomas, 1 mixed ductal/lobular adenocarcinoma), two serous papillary ovarian carcinomas and one moderately differentiated colorectal adenocarcinoma. The sensitivity of positive calretinin labelling to confirm the diagnosis of MPM was 97.5%, while the ‘diagnostic sensitivities’ of lack of labelling for BG8 and CD15 were 91.3% and 97.5%, respectively. The use of calretinin, BG8 and CD15 resulted in correct classification in 97.5% of all MPMs. All MPM cases investigated showed at least focal positive D2-40 labelling.ConclusionsWe have validated the usefulness of a minimal panel of antibodies with calretinin, BG8and CD15as the initial step to the diagnosis of MPM. D2-40 emerged as a helpful diagnostic tool for cases where our initial approach failed to conclusively diagnose MPM.