Dysgerminoma (seminoma) of the ovaries , being a high-malignant tumor, as a rule, is observed in people of young, youthful and even childhood. Dysgerminoma occurs in 0.5-4% of all ovarian tumors. More often than other ovarian tumors, it develops against the background of genital hypoplasia and underdevelopment of secondary sexual characteristics (infantilism, the late appearance of menstruation, amenorrhea, underdevelopment of the mammary glands and external genital organs, etc.), as well as with pseudohermaphroditism. Dysgerminoma does not have hormonal activity. The function of the second ovary is often preserved.
Macroscopically, a dysgerminoma is for the most part a tuberous tumor covered with a smooth shiny pink capsule. Often a tumor, as it were, consists of several nodes covered with one capsule. The consistency of the tumor is dense. Cystic areas are rare. In the section, the tumor is compact, sometimes with softening areas, fleshy, pink. There are foci of necrosis in the form of small decaying dark patches. In case of circulatory disturbance in the tumor as a result of torsion of its legs and in large areas of necrosis of ovarian dysgerminoma, it becomes flabby, the integrity of the capsule may be impaired and the color of the tumor becomes dark purple. At the beginning of its development, the dysgerminoma has a leg, is relatively mobile, located in the rectal uterine cavity. A tumor can be of various sizes (from a chicken egg to a six-month-old fetus). Dysgerminoma can be interconnected and be inactive. Sometimes (25% of cases), bilateral ovarian damage occurs.
Histologically, dysgerminoma consists of large roundish or polygonal cells with a large, moderately hyperchromic nucleus and with abundant, slightly foamy light cytoplasm.
Dysgerminoma cells are located in cells or strands amid abundant fibrous or hyalinized stroma. Often they are continuous fields without stroma. One of the characteristic signs of the structure of dysgerminoma is often encountered lymphocytic infiltration.
The origin of the tumor is as follows. As you know, in the very early stages of its development (the first 2 months), the gonad of the embryo contains primary (indifferent) sex cells (gonads), which, in the process of maturation and differentiation, acquire the properties of a male or female sex gland. Differentiation of germ cells towards the male or female gonad begins only in the second half of the third month of embryonic life. It can be assumed that in the mature ovary, elements of primary indifferent germ cells are preserved, from which dysgerminoma develops. Currently, this view on the histogenesis of dysgerminomas is accepted by most authors. The immense sensitivity of the dysgerminoma to radiation also leads to the assumption of its origin from embryonic cells.
There is no dissemination of dysgerminoma along the peritoneum, which distinguishes it from ovarian cancer, in which dissemination along the parietal and visceral peritoneum and ascites are observed. Unlike cancer, with dysgerminoma, even in advanced cases, metastases to the omentum are not observed. Metastasis goes along the lymphatic paths from the ovary, usually along the length on the affected side to the upper abdominal cavity, affecting the paraaortic lymph nodes at a kidney level and above. A tumor recurs, usually relatively quickly (within a year).
Clinic and diagnosis of ovarian dysgerminoma
The first sign of the disease is often pain. The pain is often acute and in 15% of cases, patients are admitted to the hospital with a diagnosis of “acute abdomen.” Aching pain as the first sign of the disease is observed in 40% of patients. The cause of the pain is torsion of the legs of the tumor or rupture of the capsule of a necrotic tumor. Dysgerminoma grows extremely fast. On palpation in the lower abdomen, a tumor is determined. In a two-handed vaginal examination, the tumor is mostly dense, tuberous, large, inactive, lowered deep into the rectal-uterine or vesicoureteral cavity. If the tumor grows interconnected, then the uterine body enters into the general conglomerate of the tumor and is not separately palpated. Since dysgerminoma grows rapidly, metastasizes early, sometimes its first signs are found not in the area of the primary focus, but in the area of metastases. The rapid growth of the tumor with the formation of foci of decay and the absorption of decay products leads to an increase in ESR (40-50 mm / h). With dysgerminoma, even in advanced stages, ascites does not happen.
Diagnosis of ovarian dysgerminoma
The diagnosis is usually not difficult. A dense, tuberous, sedentary, relatively large tumor in the pelvis of a young woman or teenager, the absence of ascites, increased ESR and paroxysmal pain in the abdomen always causes dysgermina. If at the same time the patient has primary amenorrhea or meager with frequent delays in menstruation, the diagnosis of dysgerminoma becomes more likely.
Differential diagnosis of ovarian dysgerminoma
Dysgermin should be differentiated from other tumors of the ovary and uterine fibroids. Differential diagnosis with uterine fibroids does not present great difficulties. Firstly, uterine fibromyoma in adolescence and childhood is rare. Secondly, the pain with dysgerminoma is relatively severe (torsion of the legs or rupture of the tumor capsule). In addition, with dysgerminoma, primary amenorrhea or scanty menstruation is observed, with fibromyoma, usually hyper- and polymenorrhea.
Differential diagnosis between dysgerminoma and any other ovarian tumor before surgery does not have much practical significance, since any ovarian tumor must be surgically removed. An important step in the diagnosis of dysgerminoma is laparotomy.
Treatment of ovarian dysgerminoma
Treatment for dysgerminoma should be comprehensive (surgical, radiation therapy, chemotherapy and hormone therapy).
Surgical treatment consists in hysterectomy with appendages in all cases, despite the patient’s young age.
Dysgerminoma is very sensitive to radiation. Typically, large irradiation fields are used so that significant tumor arrays fall into the irradiation zone. Radiation treatment is used both for direct exposure to the tumor and its metastases with the aim of resorption, and after surgery for prophylactic purposes. Irradiation is carried out from 6 fields in a total dose of up to 12 000 R.
Of the dysgermin chemotherapy, it is most sensitive to sarcolysin (single dose of 30-50 mg), and 200-250 mg per treatment course. The drug is administered intravenously once a week. In this case, leuko- and thrombocytopenia are possible.