BerEP4-negative basal cell carcinoma on the palm: case report and review of the literature.

Only 10 cases of patients with isolated basal cell carcinoma (BCC) of the palms and soles have been published. We describe a patient with an isolated basal cell carcinoma of the palm. Our patient denied injury and exposure to noxious agents; he did not have basal cell nevus syndrome. The tumor was negative for EpCAM as determined by BerEP4 immunohistochemistry, although EpCAM expression usually is seen in BCC in more conventional locations. Because the tumor cells were connected to secretory eccrine glands, we speculate that BCC of the palm originates from common progenitor cells of eccrine glands or epidermal stem cells. We review the literature on these rare BCC in atypical anatomical regions, and discuss the cellular origin of BCC in such locations.