Sebaceous adenoma is a benign skin neoplasm that develops from the epithelium of the sebaceous ducts. Clinically characterized by the presence of a yellow or pink nodule of various diameters with slow growth and the most frequent localization on the face or neck. With different types of adenomas, there are their own peculiarities in the clinical picture. Diagnosis is based on visual examination, anamnesis collection. The diagnosis is confirmed by histological and cytological examination data. Therapy includes surgical treatment: cryodestruction, electro- and laser coagulation, excision.
D23 Other benign skin neoplasms
Sebaceous adenoma is a benign skin tumor that is rarely registered as an isolated disease (1 case per 100 thousand population). Pathology is widespread everywhere, its occurrence does not depend on seasonality and geographical latitude. It is more common in children and elderly people. A significant part of cutaneous adenomas is associated with Muir–Torre syndrome. In 68% of patients with this syndrome, the presence of sebaceous gland tumors is clinically confirmed. The presence of other types of adenomas (Pringle-Burenville, Allopo-Leredda-Darye, Balzer-Menetrie) it is also due to a genetic predisposition.
There is no consensus on the nature of the occurrence of this pathology, because the etiology has not been studied enough. Reliable predisposing factors are childhood and old age, male sex and the presence of chronic pathologies from the gastrointestinal tract (colitis, enteritis, gastritis). Among the probable causes of the development of skin adenomas are considered:
- Genetic predisposition. The most common sebaceous adenomas are diagnosed with Muir-Torre syndrome, which is an association of multiple tumors of the sebaceous glands (adenoma, epithelioma, carcinoma), keratoacanthus and malignant tumors of internal organs. In addition, skin adenoma may be etiologically associated with tuberous sclerosis.
- Diseases of the sebaceous glands. One of the possible causes of sebaceous adenoma is considered to be seborrhea. The increased keratinization observed in this disease can become a trigger for the development of a tumor. This process is typical for young people with hormonal disorders.
- The impact of physical factors. A rare but clinically registered cause of adenoma is general and local hypothermia. Cases of adenomas associated with temperature exposure are considered isolated. There is a recurrence of adenoma after treatment under the action of the same provoking factors.
The neoplasm is a true tumor originating from the secretory cells of the excretory ducts of the sebaceous gland. Certain causal factors at a certain stage provoke hyperplasia of the glandular epithelium, neoangiogenesis and the formation of connective tissue. Histologically, the adenoma has a lobular structure with two cell populations: basaloid germ cells are located along the periphery of the lobules, mature seb cells are located in the center. Mature sebaceous gland cells predominate over undifferentiated forms. Nuclear atypia, necrosis foci, pronounced mitotic activity, invasive spread are absent.
In practical dermatology, there are four types of sebaceous adenoma, which differ in their clinical picture, localization, size, and age of appearance. The isolated form occurs extremely rarely and is difficult to differentiate with other species. The following clinical forms of adenomas are described in detail in the literature:
- Hirschfeld adenoma (senile). Develops in old age. It is a solitary dense nodule of rounded shape, sometimes having a leg. Predominant localization: face, back, scrotum area.
- Pringle-Burenville adenoma (cystic epithelioma). It is more often manifested already in childhood. It has the appearance of small round or oval nodules, the color of which can vary from brown-pink to yellow. The surface of the elements is smooth, dense, shiny. The fusion of nodules is not typical. Symmetrical localization of formations is characteristic – on the cheeks, nose, chin.
- Allopo–Leredd–Darye adenoma (symmetrical). It can appear at any age and place on the skin. Externally, it is a dense formation, visually similar to a wart, the color varies from skin color to pink. Elements grow rapidly, tend to merge massively.
- Balzer–Menetrie Adenoma. It may look like nodules that fit snugly to the skin, or a fibroid on the leg. The elements are dense to the touch with a smooth surface. The color usually does not differ from the skin. The most characteristic localization is the face, neck, the area of large folds, sometimes the oral mucosa. The size of the neoplasm reaches 10 mm.
Symptoms of sebaceous adenoma
The formation is a smooth, clearly bounded papule. The skin above the nodule is not changed or slightly rough. In 70% of cases, it is localized in the head or neck, less often – on the trunk and lower extremities. Sebaceous adenoma is characterized by slow growth (for several years), painlessness. Sizes vary from 5 to 25 mm. The color of the neoplasm can be from the usual bodily to pinkish or yellowish.
Sebaceous adenomas associated with Muir–Torre syndrome can be solitary or multiple (sometimes up to 100 pieces or more). The nodules have a yellowish color, a diameter of 0.5-1 cm, in some cases they grow up to 5 cm. With this syndrome, patients also have other skin tumors (keratoacanthomas, epitheliomas, carcinomas of the sebaceous glands), visceral forms of cancer.
With traumatization and ulceration, tumor foci can bleed and cause pain. Most often, an adenoma located in the periorbital zone is complicated – its damage and infection leads to the development of conjunctivitis or keratitis. After surgical excision of adenomas, scars form on the skin, causing cosmetic and sometimes functional inconveniences. Sebaceous adenomas are benign neoplasms that themselves rarely degenerate into skin cancer. However, the presence of such formations in the patient may indicate Muir-Torre syndrome, in which colorectal cancer, breast cancer, genitourinary system, stomach, head and neck, etc. are often diagnosed.
The basic diagnostic program includes an examination, assessment of the clinical picture and anamnesis of the disease (the time of the appearance of adenoma, the presence of similar formations in relatives), according to which a dermatologist can assume a diagnosis. The study of sebaceous adenoma by dermatoscopy is uninformative, so they resort to more radical diagnostic options:
- A biopsy with a study of the material. For histological examination, excision or pinch biopsy is more often used, for cytology – fine needle aspiration. Microscopic examination of the drug shows a morphological pattern characteristic of sebaceous adenoma.
- Genetic diagnostics. This type of diagnosis is relevant in the presence of familial cases of Muir-Torre syndrome. The essence of the method is to determine the defective gene that is the cause of the disease. It includes several stages: consultation of a geneticist, drawing up a pedigree, laboratory tests, and the formation of a final diagnosis.
To determine further therapeutic and diagnostic tactics, a consultation of a surgeon, a dermatooncologist is required. Sebaceous adenoma is differentiated with carcinoma, keratoacatoma, nevus and hyperplasia of the sebaceous glands.
Treatment of sebaceous adenoma
The main type of treatment is surgical. The removal option depends on the size and location of the formation, the pain threshold and the age of the patient. The optimal method is selected individually, assessing possible risks and complications in advance. To remove the sebaceous adenoma are used:
- Physical methods of destruction. Removal with liquid nitrogen is indicated only for small adenomas; this procedure is not recommended on the face. With the help of electrocoagulation, small formations are removed without residual phenomena, larger ones leave scars. Laser coagulation is the most preferred method for removing adenomas located in the face area, because it does not leave scars.
- Surgical excision. This type of treatment is rarely used. Surgical excision of large or multiple adenomas may require additional repair of the defect with local tissues. Despite the radical nature of the method, the recurrence of formations with a further increase in their size and number is not excluded.
Prognosis and prevention
Isolated adenoma is the most favorable variant of pathology, it is easily removed and does not leave scars. In the presence of adenomas in combination with Muir–Torre syndrome, the prognosis is serious due to concomitant oncology. There are no specific preventive measures to prevent skin adenoma, non-specific ones include timely treatment of seborrheic dermatitis, gastrointestinal diseases, avoidance of hypothermia. In the presence of this disease, relatives need to be monitored and seek medical help earlier.