Fig. 2
From: Clinical features and treatment of vulvar Merkel cell carcinoma: a systematic review
Photomicrographs of a typical Merkel cell carcinoma at a 4x, b 40x, and c–d 100x objectives. Hematoxylin and eosin staining demonstrates small, undifferentiated cells with high N/C ratio and scanty cytoplasm. Typical immunopanel demonstrates positive staining with e cytokeratin AE1/AE3 (100x oil immersion), f CK 20 (100x oil immersion), and neuroendocrine markers such as g chromogranin (100x oil immersion)