Fig. 1

P1 Histological analyses (hematoxylin and eosin) revealed the presence of two different phenotypes in the lung lesion of the proband. We found non-small cell lung cancer (NSCLC, 30 %; A magnification ×10; B magnification ×40) and pulmonary enteric adenocarcinoma (PEAC, 70 %; C magnification ×10; D magnification ×40). Table 1 summarizes the marker expression associated with these two different phenotypes. The expression of TTF1 and CDX2 was associated with NSCLC and PEAC, respectively. Strong expression of CK7 was observed in both phenotypes (100 %). P2 Immunohistochemical signatures in NSCLC (left panels) and PEAC (right panels). TTF1 (A, B, C, and D); CK7 (E , F , G, and H); CDX2 (I , L , M, and N); and CK20 (O , P , Q, and R) staining showing co-localizations of TTF1/CK7 and CDX2/CK7 in NSCLC and PEAC, respectively. Columns 1 and 3 (magnification ×10); columns 2 and 4 (magnification ×40). P3 Mucins (MUCs) expression in PEAC and pancreatic intraductal papillary mucinous neoplasms (IPMNs). Strong coexpression of MUC1 and MUC5AC was observed in the area with PEAC histology. Conversely, in the same area, we did no detect MUC2 expression. Examples of the positive expression of MUC1 (D), MUC2 (E), and MUC5AC (F) associated with different subtypes of IPMNs. Columns 1 and 2 (magnification ×40). P4 Summary of mucins (MUCs) expression in the different subtypes of IPMNs and in our PEAC samples showing similar molecular markers expression. In particular, the negative expression for MUC6 (data not shown) suggests a pancreatobiliary differentiation of areas within our PEAC sample