Internally Peer Reviewed This field is from a better differentiated area of the tumor, showing two nests of tumor cells. The larger nest on the right shows evidence of keratinization, seen in the larger cells with the amorphous eosinophilic cytoplasm.
Keratinization is a feature of squamous cell carcinomas.
The nest of squamous cells in the upper left doesn't have any keratinization. These two nests contrast the variability and differentiation present in many cases of squamous cell carcinoma. This becomes a factor when small biopsies, such as transbronchial biopsy or fine needle aspiration are used. Depending on the area biopsied, the area may be diagnosed non small cell carcinoma or squamous cell carcinoma. If the nest on the left were biopsied, it would only allow a diagnosis of non small cell carcinoma.