This is a squamous cell carcinoma. Note the disorderly growth of the squamous epithelial cells in these large nests with pink keratin in the centers. Thus, these neoplastic cells retain the ability to make keratin, similar to normal squamous epithelial cells. Neoplasms may retain characteristics of their cell of origin. Benign neoplasms mimic the cell of origin very well, but malignant neoplasms less so.