Invasive cutaneous squamous cell carcinoma associated with actinic keratosis: a case with orbital invasion and meningeal infiltration.

BACKGROUND It is suggested that most squamous cell carcinomas in sun-exposed areas arise from preexisting solar keratosis. Actinic keratosis is thought of as being a precursor to squamous cell carcinoma. This form of squamous cell carcinoma has been considered to be a relatively benign lesion. We report a case of invasive squamous cell carcinoma associated with actinic keratosis leading to orbit destruction and meningeal infiltration. OBJECTIVE To demonstrate that well-differentiated tumors can act extremely aggressively with the potential toward infiltrative growth patterns. METHODS Histologically controlled surgery along with multiple radiation therapy was performed. RESULTS The tumor progressed inducing perineural invasion, orbit infiltration, osseous destruction, and meningeal invasion. CONCLUSION The association of squamous cell carcinoma and actinic keratosis supports the concept of a causal relation. Excision with histologic examination of actinic keratosis seems to be useful for accurate diagnosis. Squamous cell carcinoma can represent an aggressive tumor with infiltrative growth pattern and should not be considered a benign lesion.