SYP and small cell lung carcinoma: In 37 cases (15.3%), there was a morphological suspicion of a small-cell lung carcinoma (SCLC), in 2 cases (0.8%) of typical carcinoid, in 2 (0.8%) cases of atypical carcinoid tumor, and in 1 (0.4%) case of a large-cell neuroendocrine carcinoma (LCNEC), so they were subjected to immunohistochemical investigation for synaptophysin (Figure 2).