What type of carcinoma is characterized by the presence of marked nuclear atypia?

Squamous cell carcinoma is known for its marked nuclear atypia, which is a key histopathological feature. In this type of carcinoma, the cells often exhibit significant variations in the size and shape of their nuclei, as well as prominent nucleoli. This nuclear atypia reflects the disordered growth and differentiation typical of malignant tumors. Moreover, squamous cell carcinoma arises from the keratinizing epithelial cells and can present in various sites, particularly where squamous epithelium is found, such as the skin, oral cavity, and respiratory tract.

The assessment of nuclear atypia is crucial in diagnosing squamous cell carcinoma, as it helps pathologists distinguish it from other lesions and carcinomas that may not display such pronounced nuclear changes. In contrast, the other carcinomas listed tend to have different cellular characteristics and may not present with the same degree of nuclear atypia that is typically observed in squamous cell carcinoma.