Despite the former belief that its immunohistochemical expression was highly restricted to cells of adenocarcinomas derived from the lung and thyroid, recent studies have hinted that the expression of TTF-1 is not as specific as was initially thought, and that it can be also found in primaries and metastases from other body sites (albeit to a lesser extent) [9,10,11]. Here, TTF1 is linked to adenocarcinoma.