Ovarian teratoma is a germinogenic tumor of the ovary containing tissues atypical for this organ, which are derivatives of germ leaves. It can be mature or immature. It usually proceeds asymptomatically or malosymptomno. It is manifested by bursting pains in the lower abdomen, violations of urination and defecation, less often – an increase in the size of the abdomen. Immature ovarian teratomas can germinate nearby tissues and metastasize. The diagnosis is made taking into account clinical symptoms, gynecological examination data, ultrasound with CDM and CT of the pelvic organs. Surgical treatment – partial resection of the ovary or amputation of the uterus with appendages.
Ovarian teratoma is a tumor of the ovary of a mixed structure, originating from polypotent embryonic cells and including derivatives of three germ leaves. It contains tissues atypical for this organ: fragments of multilayer flat keratinizing epithelium, striated muscles, bones, cartilage, nervous tissue, etc. Sometimes, when examining ovarian teratomas, the rudiments of organs and parts of the body of varying degrees of maturity are revealed (for example, the eyeball, part of the trunk or limbs). It makes up 25-30% of the total number of teratomas of various localization.
Ovarian teratoma can be detected in childhood, adolescence and reproductive age, less common in women during menopause. It can be mature or immature (teratoblastoma). Mature neoplasias are benign, immature ones are malignant. In some cases, mature ovarian teratomas may become malignified. Neoplasms do not prevent conception, but they can disrupt the normal course of pregnancy, cause miscarriages and premature birth. The treatment is carried out by specialists in the field of oncology and gynecology.
Causes and pathanatomy
The etiology of the disease is not exactly clarified. It is assumed that ovarian teratomas are the result of abnormal embryogenesis resulting from chromosomal failure. There is also a theory according to which teratomas (or part of teratomas) are formed when the development of identical twins is disrupted and one twin is subsequently absorbed by another. Taking into account the level of tissue differentiation, mature and immature ovarian teratomas are distinguished. Mature neoplasms may have a cystic (dermoid cyst) or solid structure. Such neoplasias are characterized by slow non-aggressive growth and lack of ability to metastasize. Immature neoplasms can germinate nearby organs, give lymphogenic and distant metastases.
Usually a mature ovarian teratoma is a single node of uneven consistency, covered with a dense, smooth and shiny fibrous capsule. The diameter of the tumor ranges from 3-5 to 15 cm. Under the capsule there is a single-chamber cyst, the walls of which are lined with cubic or cylindrical epithelium. Multicameral ovarian teratomas are rare. The cyst cavity is filled with thick whitish contents, in which hair is often found, less often teeth. Microscopic examination of the cyst contents usually reveals derivatives of exoderm and mesoderm.
In mature ovarian teratomas, elements of sebaceous glands, epithelial scales, areas of the dermis, nerve ganglia, neurocytes, muscle fibers, areas of cartilage, bones and connective tissue are found. Less often, such tumors contain endoderm derivatives: elements of glandular tissue, areas of epithelium resembling the epithelium of the bronchi, stomach and intestines. All tissues of mature ovarian teratoma “mature” according to the age of the patient and lose the ability to progressive growth, which causes a benign course of such neoplasms. Malignant degeneration is rarely observed.
Unlike mature neoplasias, the tissues of immature ovarian teratoma retain an embryonic structure and have the ability to uncontrolled proliferation. Immature ovarian teratomas are single formations of uneven consistency with a bumpy surface. In the initial stages, they have a capsule. Subsequently, the germination of the capsule and nearby tissues is detected. Microscopic examination of immature ovarian teratoma, regional and distant metastases reveals immature tissue elements that are derivatives of ectoderm, mesoderm and endoderm. Foci of necrosis are detected in the tissue of the formation.
Mature tumors are characterized by an asymptomatic or low-symptomatic course. Teratomas become a random find when conducting an examination for other reasons or are manifested by heaviness and indistinctly expressed pulling or bursting pains in the lower abdomen, reminiscent of pain before the onset of menstruation. With large ovarian teratomas, increased urination, difficulty urinating and defecation are possible. Patients with asthenic physique sometimes have an increase in the size of the abdomen. The menstrual cycle is not broken.
Sometimes ovarian teratomas are first detected after pregnancy. This may be due to the acceleration of the growth of the neoplasm with a change in the hormonal background, increased pressure of the tumor on the uterus and pelvic organs, or twisting of the leg of the teratoma. The twisting of the leg of the ovarian tumor is accompanied by intense pain. It is an urgent condition requiring emergency surgical intervention.
In the absence of timely help, necrosis of the ovarian teratoma wall is possible, followed by rupture of the cyst, ingestion of its contents into the abdominal cavity and the development of peritonitis. In pregnant women, twisting the cyst legs can lead to miscarriage or premature birth. Ovarian teratomas in pregnant and non-pregnant patients can become infected with the development of an inflammatory process, manifested by severe pain, sharp weakness and an increase in body temperature.
With immature ovarian teratomas (teratoblastomas), lethargy, weakness, increased fatigue and pain in the lower abdomen are observed. With the progression of the process, moderate normochromic anemia, weight loss, pallor and dry skin are noted. The increase in the size of the ovarian teratoma and the germination of nearby organs cause a change in the nature of pain, defecation and urination disorders. In the later stages, the classic picture of cancer intoxication is revealed in combination with impaired functions of organs affected by distant metastases. Metastasis to the lungs is most often detected.
The diagnosis of this pathology is carried out taking into account the clinical symptoms and the results of instrumental studies. During gynecological examination, patients with ovarian teratoma are found to have a painless tumor-like formation on a long leg, located on the side or in front of the uterus. According to the review radiography of the abdominal cavity, bone inclusions in the ovary area are detected (in the presence of sufficiently large fragments of bone tissue).
Ultrasound with CDM of mature ovarian teratoma confirms the absence of vascularization in the area of the cyst cavity. The study of an immature ovarian teratoma determines the chaotic structure of the node, the alternation of cystic and solid areas, the presence of uneven blood supply with the formation of new vessels and arteriovenous shunts. Echography indicates a heterogeneous structure of the neoplasm (hypoechoic areas alternate with hyperechoic). If necessary, along with the above studies, patients with ovarian teratoma are prescribed a CT scan of the pelvic organs for a more accurate assessment of the structure of the tumor. In case of diagnostic difficulties, laparoscopy with biopsy is performed. To identify signs of malignancy, an analysis is performed for cancer markers.
Treatment and prognosis
The treatment is operative. The volume of intervention is determined by the degree of maturity of the neoplasm and the age of the patient. With mature ovarian teratomas in patients of childbearing age, partial resection of the ovary is performed (possibly using laparoscopic access), in menopausal women, supravaginal amputation of the uterus with adnexectomy is performed. With immature ovarian teratomas, regardless of the patient’s age, a pangisterectomy is performed. Removal of the uterus with appendages is supplemented by extirpation of the omentum. Radiation therapy for malignant tumors of this type is ineffective. In some cases, some success can be achieved with multicomponent chemotherapy.
The prognosis for mature ovarian teratomas is favorable. After removal of the tumor, the reproductive function is preserved. Due to the possible acceleration of growth and twisting of the leg, the presence of an undetected tumor can interfere with the normal course of pregnancy, creating an increased threat to the mother and fetus, therefore, gynecologists recommend resecting such neoplasia before gestation. Immature ovarian teratomas are considered as prognostically unfavorable. There are no preventive measures. For timely detection of mature and immature ovarian teratomas, women should undergo regular gynecological examinations.