Fig. 4
From: Neuroendocrine differentiation distinguishes basaloid variant of lung squamous cell carcinoma
The photomicrographs show the morphological features and immunohistochemical profile of a tumor exhibiting small cell lung carcinoma (SCLC) morphology transitioning to basaloid carcinoma (B-SqCC) features. A The SCLC characterized by hyperchromatic densely packed cells with scant cytoplasm on the left (*) and pure B-SqCC with hyperchromatic nuclei surrounded by moderate eosinophilic cytoplasm on the right (**). The immunohistochemical stains highlight the transitioning spatial differentiation with B TTF-1 positive staining in SCLC and negative staining in pure B-SqCC and conversely C p40 negative staining in SCLC and strong positive in pure B-SqCC. On the other hand neuroendocrine stains including D Chromogranin, E Synaptophysin and F CD56 are positive in SCLC while pure B-SqCC is either focally positive or is negative