Sebocystomatosis is a dermatological disease caused by cystic neoplasms originating from the epithelium of the ducts of the sebaceous glands. It is accompanied by the appearance of hemispherical tumor-like formations on the skin of the scalp, face, neck, chest, genitals (scrotum in men and labia majora in women), thighs. Diagnosis of sebocystomatosis is based on the results of dermatological examination and histological examination of neoplasia tissues. Treatment includes surgical removal of cyst-like formations and the use of retinoid-based external agents.
General information
Sebocystomatosis (steatocystomatosis, steatodystomatosis) is a dermatological condition of unclear (presumably genetic) etiology, in which there is a pathological proliferation of sebaceous gland tissues with the development of cystic neoplasms. For the first time this disease was described by Boselini in 1898, the researcher considered the cause of the formation of cysts excessive keratinization of the skin, accompanied by blockage of the lumen of the sebaceous glands. However, further histological studies have shown that cystic neoplasms, in fact, are benign tumors. Both men and women suffer equally from sebocystomatosis, but there are separate indications that the frequency of this disease is slightly higher in males. Several family cases of sebocystomatosis are reliably known, which serves as additional evidence of the genetic nature of its origin. In addition, skin manifestations similar to sebocystomatosis sometimes accompany hereditary diseases – congenital pachionychia and some forms of lichen planus. Most dermatologists attribute sebocystomatosis to facultative precancerous conditions of the skin.
Causes
The etiology of sebocystomatosis has not been reliably determined to date, there are only a few basic theories explaining the causes of its occurrence. The most common hypothesis in dermatology connects this condition with mutations of genes located on the 17th chromosome. There are suggestions that this is a type 17 collagen gene, which is most widely represented in the sebaceous glands. However, the pathogenesis of the development of sebocystomatosis with mutations of this gene is unknown – it is possible that type 17 collagen somehow affects the contact inhibition of the division of the epithelium of the ducts of the sebaceous glands. An additional argument of the supporters of the genetic hypothesis of the occurrence of this dermatological disease is the presence of familial forms of sebocystomatosis.
According to another opinion, the causes of sebocystomatosis lie in violation of intrauterine development – local detachment of the epidermal germ or other defects. Histological studies have shown that many of these neoplasms have the features of dermoid tumors, for example, the beginnings of hair and other exodermal elements are found in their thickness. In addition, cases of combination of sebocystomatosis with malformations of teeth, auricles, nails are described, which indicates a factor of dysembriogenesis. The third most common theory of the development of this disease relates characteristic cystic neoplasms to a variant of the usual non-cancerous skin tumors.
Symptoms
The development of sebocystomatosis, as a rule, begins in childhood, sometimes in adolescence. The main symptom of this condition is the appearance of hemispherical tubercles on the skin. The bumps have a dense consistency, are painless and seem to “sprout” from the skin. Their localization can be different – the scalp, face and neck, back, genitals. In men, there are forms of sebocystomatosis with the development of tubercles exclusively on the skin of the scrotum. The number of such cystic neoplasms can vary from one or two to several dozen or even hundreds. Particularly severe cases of sebocystomatosis are described, in which tumors cover almost the entire surface of the patient’s skin.
Most often, with sebocystomatosis, neoplasms on the skin occur in groups consisting of closely touching, but not merging cysts. The tubercles are covered with unchanged skin, sometimes acquire a yellowish color, and a hole is formed on their top, through which a thick oily mass is released when pressed. The size of cysts with sebocystomatosis can range from 2 millimeters to 1-2 centimeters. Inflammation and secondary infection are uncharacteristic, such complications are observed only with significant trauma, while after healing, the tubercle usually disappears, and a noticeable scar remains in its place. Causeless redness, itching, soreness, ulceration of cysts with sebocystomatosis may indicate malignant degeneration and require immediate consultation with an oncologist. According to various data, transformation into squamous cell skin cancer is observed in 2-6% of patients.
Diagnosis and treatment
Diagnosis of sebocystomatosis is based on the analysis of the clinical picture of the disease and histological examination of the tissues of skin neoplasms. Examination reveals cysts of various localization with a size of 2-20 millimeters, usually formed into groups – in dermatology, such a structure is called “boiling resin”. A characteristic feature of neoplasms with sebocystomatosis is the solidity of their tops with the epidermis with the free placement of the base on the skin – this is determined by palpation. Some of the cysts have a small hole at the top, through which a thick curd oily mass is released when pressed. Sebocystomatosis is characterized by a long course (for many years), in which new cysts develop, and old formations disappear only if they become inflamed or traumatized.
When opening the cyst cavity, it is found that it is filled with a white mass, in which hair is sometimes found. Additional studies, such as sowing the contents of the cyst on nutrient media, confirm the absence of bacteria – the tumor cavity is normally absolutely sterile. The chemical composition of the contents is similar to blood plasma lipids. The histological structure of the wall of neoplasms in sebocystomatosis is two–layered – the inner shell is represented by an epithelium similar to that in the ducts of the sebaceous glands, the outer one is a connective tissue capsule. Adhesions of the cyst with the epidermis are caused by strands of poorly differentiated cells of epithelial origin. With complications of sebocystomatosis, signs of malignancy may be detected in cysts – a violation of the two-layer structure, the appearance of poorly differentiated flat cells with a large nucleus.
Treatment of sebocystomatosis is performed only by removing neoplasms using various techniques: surgical excision, electrocoagulation, laser ablation. At the same time, in most cases, the procedure has to be repeated every few years, since new cysts appear on the patient’s skin over time. Etiotropic treatment of sebocystomatosis has not been developed, it is impossible to prevent the recurrence of the disease after the elimination of rashes. According to some reports, the external use of aromatic retinoids on the affected areas of the skin can prevent the development of new cysts and even greatly slow down the development of the tumor process that has already begun. Before surgical removal of neoplasms, a mandatory consultation with an oncologist is necessary to exclude such a complication as squamous cell skin cancer.
Prognosis and prevention
Regarding the patient’s survival, the prognosis of sebocystomatosis is quite favorable, since cysts almost never cause life-threatening conditions. The exception is cases of degeneration of neoplasms into squamous cell skin cancer, observed in several percent of patients. For this reason, sebocystomatosis is considered an optional precancer, and those suffering from it should regularly (every few months) undergo a medical examination by a dermatologist or oncologist. Often such formations become a cause of aesthetic discomfort and a source of psychological problems. Since the etiology of this condition remains largely unclear, specific prevention of sebocystomatosis has not been developed to date.