What are patterns of basal cell carcinoma?

➢ Two common patterns are seen: • multifocal superficial growths, originating from the epidermis, • nodular lesions growing downward into the dermis as cords and islands of variably basophilic cells with hyperchromatic nuclei, embedded in a fibrotic or mucinous stromal matrix. ➢ Peripheral tumor cell nuclei align in the outermost layer (a pattern termed palisading), which often separates from the stroma, creating a characteristic cleft ➢ By far the most important risk factor is cumulative sun exposure; ➢ Advanced lesions may ulcerate, and extensive local invasion of bone or facial sinuses may occur if the lesions are neglected. ➢ Metastasis is exceedingly rare.