Pleomorphic basal cell carcinoma: case reports and review

Pleomorphic basal cell carcinoma is a pathologic variant of basal cell carcinoma characterized by the presence of atypical-appearing, mononuclear or multinucleated giant cells. Including our 3 patients, a total of 52 pleomorphic basal cell carcinomas have been described in 48 individuals. The tumors usually present as a nodule on the head or neck. The nuclei of the giant tumor cells are irregularly shaped, hyperchromatic, and 2 to 10 times larger than the nuclei of the surrounding cancer cells. Atypical mitoses may be present. The pathogenesis of pleomorphic basal cell carcinoma remains to be determined; however, investigations utilizing electron microscopy, immunohistochemistry, image analysis, and flow cytometry have provided additional insight regarding the features of the giant tumor cells and the etiology of this cancer. All of these tumors are aneuploid. Although these aneuploid tumors have alarming microscopic features, their clinical course is similar to that of basal cell carcinomas without pleomorphic giant tumor cells. Therefore, appropriate therapy to ensure adequate treatment of the tumor is recommended. Our patients' pleomorphic basal cell carcinomas were successfully treated by excision using the Mohs micrographic surgical technique.