Fig. 3

Pathological findings of the resected lung nodule and hilar lymph node in a 72-year-old man with coexisting lung cancer and immunoglobulin G4-related disease. In the lung nodule, a lepidic pattern of adenocarcinoma coexisted with lymphocytes and plasma cells (hematoxylin and eosin, ×400). The infiltrating lymphocytes and plasma cells are positive for b immunoglobulin G and c immunoglobulin G4 staining (×400), with an immunoglobulin G4 to immunoglobulin G ratio of more than 40 %. d Obliterative phlebitis findings ("arrows") in the lung nodule (Elastica van Gieson, ×200). In the hilar lymph node, e the infiltration of plasma cells are seen with storiform fibrosis (×100) and f these cells were positive for immunoglobulin G4 staining (×400)