Pathology of Primary Nonlymphoid and Non-mesenchymal Skin Cancer

Skin cancer represents the most common type of human cancer and encompasses a great number of malignant neoplasms deriving from different cells of the human skin [1]. The most common tumors arise from epithelial cells of the epidermis and the adnexa. There are also tumors of neuroendocrine cells (Merkel cell carcinoma) [2] or of melanocytes, namely, melanoma [3]. The other tumors derive from the lymphohematopoietic system [3] and the mesenchyme.