Considering the relation to the general pathology, skin tumors were classified on the basis of the embryology as follows:
1) the ectodermal epithelial tumors tumors of the surface epidermis tumors of the epidermal appendages
2) the ectodermal nervous tumors tumors of the melanocyte tumors of the nerve tissue
3) the mesodermal nonepithelial tumors tumors of the connective substances tumors of the muscular tissue
4) the mesodermal vascular tumors tumors of the blood vessels tumors of the lymphatic vessels
5) reticulosis
6) metastatic tumors.
In 1) -4) class, benign and malignant tumors occur.
Squamous cell carcinoma and basal cell carcinoma were described of the histological pictures of various types and differential diagnosis.
The tumors occuring from the intraepidermal parts of appendages were classified and explained the histological pictures. To add to the above, the problems of the intraepi-dermal epithelioma were discussed.
The histological pictures of nasal glioma, neurilemmoma (Antoni B type), nodular fasciitis, desmoid tumor, hibernoma, liposarcoma, granular cell myoblastoma, Kaposi sarcoma, alveolar soft-part sarcoma and metastatic carcinoma of the skin from renal carcinoma were showed.