Cutaneous endometriosis is a benign proliferation of dermal tissues morphologically similar to the inner lining of the uterus (endometrium). Clinically manifested by the formation of solitary or multiple dense lobular nodes of a purple hue, mainly located in the genital area, navel and postoperative scars of the anterior abdominal wall. A feature of these formations is their ability to increase in size and bleed during menstruation. The diagnosis is made on the basis of the clinic, confirmed histologically. Treatment – radical excision of nodes with cytology to exclude metaplasia.
N80.6 Skin scar endometriosis
Cutaneous endometriosis is a benign hyperplasia of the skin and mucous membranes, functionally and morphologically identical to the inner lining of the uterus. If genital endometriosis accounts for about 10-70% of all gynecological pathology, then skin lesions, according to various authors, account for from 0.4% to 4%. Pathological manifestations resembling endometriosis are described in the manuscripts of Ancient Egypt. The first professional description of cutaneous endometriosis in 1860 was made by the German pathologist Friedrich von Recklinghausen.
The term “endometriosis” was introduced into medical practice in 1892 by the English gynecologist B. Bell, and the American gynecologist D. Sampson, based on observations of patients from 1921 to 1927, proposed a theory of the occurrence of skin endometriosis (migration of exfoliated endometrial cells). Cutaneous endometriosis has a pronounced gender coloring, is all-season and non-endemic. The urgency of the problem is associated with an increase in the number of cases of the disease, as well as with the possibility of malignancy of endometriosis nodes.
The pathological process is polyetiological. However, none of the reasons that can initiate cutaneous endometriosis is able to fully explain the mechanism of its development and the variety of localization of endometriosis nodes. The key point is still unclear – how the endometrial cell attaches to the skin and mucous membranes and becomes atypical. Probably, this requires a number of concomitant factors: hormonal failures, disorders in the immune system, genetic mutations, inflammation, poor ecology, intracellular changes. Triggers of cutaneous endometriosis are:
- the beginning of monthly,
- intrauterine device,
- termination of pregnancy,
- gynecological manipulations,
- inflammatory diseases of the female genital area,
- iron deficiency anemia,
There are three main mechanisms of development today: embryonic, metaplastic and endometrial.
In the endometrial (implantation) pathological process, rejected endometrial cells during the menstrual cycle, due to the anatomical features of the uterus and appendages, move not only through the cervical canal into the vagina, but also through the fallopian tubes in the opposite direction into the abdominal cavity (retrograde menstruation).
Then these cells attach to the surface of the peritoneum and take root in it. The final stage of the process is the vascularization of the formed lesion and the transportation of pathological cells to the skin. In parallel, fragments of the rejected endothelium begin to produce special enzymes (MMP), which become a matrix for adhesion (attachment) of pathological cells.
At the same time, the balance between humoral and tissue immunity is disturbed in the dermis, the number of T-killers and T-suppressors decreases, the number of pathogenic antigens that the immune system cannot cope with increases, an autoimmune reaction begins, and pathological cells are implanted into the skin with the development of its infiltration and stroma proliferation. Most likely, in this case, endometrial cells acquire the properties of stem cells, which allows them not only to be implanted, but also to begin active division with the formation of endometrious nodes in the skin.
A type of endometrial mechanism of the pathological process is iatrogenic cutaneous endometriosis, when pathological cells are transferred to the skin mechanically during medical operations on the pelvic organs or during delivery by caesarean section.
Metaplastic cutaneous endometriosis involves the replacement of normal dermal cells with pathologically altered endometrial tissue. This is due to the fact that the endometrium and epithelium lining the cavities of organs and tissues, including the vascular wall, develop from a single embryonic leaf. Therefore, the endothelium of lymphatic and blood vessels can be transformed in utero into foci of endometrial cells. At the birth of a child with a lymphatic current, these pathologically altered cells are “thrown” into the skin of the newborn, where they eventually form foci of cutaneous endometriosis. Indirectly, this is confirmed by cutaneous endometriosis in girls before the onset of menstruation.
Metaplastic transfer of endometrial cells is also possible in adulthood. In this case, against the background of immune dysfunction, spontaneous dissemination of endometrial cells occurs through lymphatic and blood vessels, their introduction into the dermis, consolidation in it with the launch of autoimmune processes, inflammation and proliferation in the system of general and local immunity. Embryonic cutaneous endometriosis occurs under the condition of an embryonic failure during the laying of organs and tissues of the unborn child. In this case, mosaic dissemination of altered endometrial cells is possible, including into the future dermis.
The genetic mechanism
Modern ideas about cutaneous endometriosis are concentrated on the genetic mechanism of pathology development, which has not been fully studied. It is known that genetic inheritance of low progesterone levels leads to the development of hormonal dysfunction, a decrease in general and local immunity, and the inability of the immune system to prevent the implantation of pathological endometrial cells into the dermis. Cytological studies confirm the connection of the HLA tissue compatibility antigen, unique for each patient, with endometriosis. In addition, hereditary genomic instability in the area of endometriosis nodes and expression of genes involved in embryogenesis were noted in skin endometriosis.
The pathological process in the skin is a kind of extragenital endometriosis. The peculiarity of this pathology is the ability of endometriosis nodes to be an independent pathological process or to act as a component of another disease. In this regard, cutaneous endometriosis is traditionally divided into two variants:
- a cutaneous extragenital variety (class O) with lesions of the skin, mucous membranes, navel area and postoperative scar,
- a combined variety representing a combination of cutaneous nodes of endometriosis with nodes of other organs, mainly sexual.
In modern dermatology, the classification proposed in 1996 by the American Fertility Society is more often used and includes 4 stages of pathology, taking into account the depth and area of skin endometriosis lesion:
- stage 1 – minimal (up to 5 points)
- stage 2 – mild (up to 15 points)
- stage 3 – moderate (up to 40 points)
- stage 4 – severe (more than 40 points).
The clinic of cutaneous endometriosis is typical. It is characterized by the formation in the area of postoperative scars, breast, conjunctiva, navel, groin, vulva or around the anus of lobular nodes of dense elastic consistency with a bluish tinge of no more than 5 cm. Formations are prone to peripheral growth, closely related to the uterine cycle. In some patients, the formation of nodes is asymptomatic, they are detected only during medical examination, in others the condition worsens so much that patients cannot work. A few days before menstruation, pain occurs in the area of the skin nodes, which are combined with pain in the lower abdomen. Nodes harden, swell, increase in size, become bright pink.
Fistulas may appear on the surface of the node, blood is released through the fistulas during menstruation. The menstruation itself becomes abundant and prolonged, sometimes accompanied by prodroma. With the end of menstruation, the symptoms disappear. If cutaneous endometriosis is combined, then there are symptoms associated with the organ in which the node of endometriosis appeared (adnexitis, cystitis, nephritis, pulmonary hemoptysis). When removing the uterus without appendages, the symptoms of cutaneous endometriosis are still detected, since ovulation persists.
Rarely, the nodes of cutaneous endometriosis become malignant. It should be noted that patients with cutaneous endometriosis are at allergic risk due to the constant circulation of tissue toxins in the blood, formed due to the decay of keratinocytes during the formation of the endometriosis node. Hormonal and immune failures aggravate the situation.
The clinical diagnosis is not difficult and can be made by both a dermatologist and a gynecologist based on anamnesis, symptoms of the disease and histological analysis. In the biopsy of the endometriosis node of the skin, epithelial and stroma cells are found, similar to the cells of the mucous membrane of the uterine cavity. Taking into account the possible asymptomatic course of combined cutaneous endometriosis, ultrasound, colposcopy, hysteroscopy, hysterosalpingography, and a blood test for the marker CA-125 are necessary. Differentiate skin endometriosis with:
- pyogenic granuloma,
- varicose veins of the umbilical veins.
Treatment of cutaneous endometriosis is surgical. Nodes are excised within healthy tissues. In the combined variant, hormone therapy is prescribed after removal according to individual schemes and after mandatory consultation with a gynecologist-endocrinologist. To relieve pain, electrophoresis with lidase to the node area, sinusoidal currents, acupuncture, hirudotherapy are used. Sanatorium-resort treatment is indicated.
Prognosis and prevention
The prognosis for life is favorable, the likelihood of relapses depends on the timeliness of treatment and the age of the patient. A multifactorial and carefully planned approach to the treatment of genital endometriosis, the maximum elimination of modifiable risk factors, allows to prevent the development of the cutaneous form.