Fig. 2

18F-FDG-PET Findings and SCLC Histology. a FDG-avid lesion in the right upper pulmonary lobe (red arrow) and non-specific uptake in cervical lymph nodes as a consequence of a mild inflammation. b Hematoxylin and eosin (HE) staining (magnification × 200), shows the tumor with typical basophil small cells with sparse cytoplasm and irregular nuclei. c Immunohistochemical (IH) staining for Synaptophysin (magnification × 200). Tumor tissue stains positive (brown), confirming neuroendocrine differentiation. d IH staining for Ki67 (magnification × 200) marks proliferating cells in a tumor. Proliferation rate was up to 70% in this case. e IH staining for TTF-1 (magnification × 200), shows the typical nuclear staining of cells of pulmonary origin