It is sometimes difficult to differentiate a squamous cell carcinoma from an actinic keratosis. This differentiation is especially difficult on the vertex of the scalp.

Thick actinic keratosis of the scalp has a similar appearance to squamous cell carcinoma

Keratoacanthoma has a well-defined central keratotic structure. The lesion is round and smooth. Scissor excision were blunt dissection usually shows a well-defined base. These tumors grow very rapidly in a matter of weeks. The pathologist today report them as squamous cell carcinomas keratoacanthoma type. Most of these lesions are benign and would not metastasize if left untreated. The classic description is a growth that appears, grows rapidly and then resolves. Most clinicians do not wait for resolution but shows excision as the treatment of choice. The procedure only needs to be conservative.

Keratoacanthomas have a central area that contains dense scale

Warts, seborrheic keratoses and basal cell carcinomas can also sometimes be confused with squamous cell carcinoma.

Irritated seborrheic keratosis is sometimes difficult to differentiate from a squamous cell carcinoma