Characterstic of basal cell carcinoma is:
Basal cell carcinomas are composed of islands or nests of basaloid cells (i.e. cells resembling cells in the normal basal cell layer of the epidermis), with palisading of the cells at the periphery and a haphazard arrangement of those in the centers of the islands. The tumor cells have a hyperchromatic nucleus with relatively little, poorly defined cytoplasm. 
Other options:
Keartin pearls- seen in squamous cell carcinoma
Foam cells- seen in Xanthoma
Psammoma bodies- seen in papillary thyroid carcinoma
Keratin pearls
Foam cells
Nuclear palisading
Psammoma bodies