Clear Cell Squamous Cell Carcinoma: Clinical and Histologic Parameters and a Review of the Literature

Background: Clear cell squamous cell carcinoma (ccSCC) is an uncommon subtype of squamous cell carcinoma. This tumor subtype arises more commonly in elderly individuals and occurring greater upon sun-exposed areas of the body.Objective: To determine the age range and locations of ccSCC, and occurrence in men as compared with women.Methods: An observational study of ccSCC accessioned at a dermatopathology laboratory (Cleveland Skin Pathology, CSP) over an 18-month interval. Cases were retrieved and included based on a search of the terms “clear cell squamous cell carcinoma” in the diagnosis field of the CSP database and reviewed for accuracy and the degree of clear cell change in each lesion. Pathology requisition forms from these cases were used only to identify patients’ age, gender, and anatomic region of the ccSCC reviewed.Results: Of the 17,838 cases of in situ and invasive SCC, there were a total of 107 ccSCC, 77 in situ and 30 invasive (0.6% of total SCC). Of patients with ccSCC, 71% had a history of skin cancer, many (57.9%) in the same anatomic region. When the degree of clear cell change was evaluated there was no statistically significant increase of percentage clear cell change in tumors with age.Conclusions: Along with confirming past observations made with previous studies, our series shows that more men than women develop such tumors before 70 years of age, and more women than men after 70 years of age with men developing ccSCC on average 7 years earlier than women.