To date, the embryogenesis of sebocystomatosis has not been fully understood and remains a matter of controversy. A hundred years ago, many dermatologists regarded lesions as fatty or retention cysts. Some authors believe that cysts are formed as a result of excessive keratinization leading to a delay in the secretion of sebaceous glands.
Dermatofibroma is a benign tumor of connective tissue in the form of a slowly growing painless knot. The causes and pathogenesis of dermatofibromas have not been studied.
Solitary or multiple lesions appear on open areas of the skin (face, neck, upper limbs). First there are erythematous spots, then on these sites develops a limited, hyperkeratosis.
The cutaneous horn arises from the proliferation of the epidermis, especially against the background of senile keratosis, common warts and keratoacanthoma. Among the provoking factors distinguish microtraumas, insolation, viral infections, etc.
Trichoepithelioma (synonyms: adenocystic epithelioma of Brooke, trichoepithelioma nevus, etc.) represents a developmental disorder of the hair follicle and sweat glands.
Erythroplasia Keira is considered as an intra-epidermal cancer and belongs to the carcinoma group in situ. In the development of the disease, non-observance of personal hygiene is of great importance. Many dermatologists believe that Keira's erythroplasia is a variant of Bowen's mucous and semilucid diseases.
Squamous cell carcinoma of the skin (synonym: spinal cell carcinoma, spinaloma) is the most malignant tumor of all epithelial skin newly formed. It occurs mainly in the elderly, equally common in men and women.
Dermatofibrosarcoma bulging arises usually in men between the ages of 30 and 40 years, but it can also be in children. The tumor is often located in any part of the skin, but more often on the trunk.
In the emergence of the disease an important role is assigned to the 3rd and 5th types of human papillomavirus (HPV-3 and HPV-5). It is possible to transform verandiiform epidermodysplasia of Lewandowski-Lutz into squamous cell carcinoma or Bowen's disease. There is information about the important role of hereditary factors.
Angiosarcoma (synonym: malignant hemomanioendothelioma) is a tumor that develops from the endothelial cells of blood vessels. The disease is often localized to the scalp and face, but can also occur in other sites in older men.