Dysgerminoma of the ovary

　　Dysgerminoma of the ovary originates from undifferentiated primordial germ cells and is named dysgerminoma. Dysgerminoma is mostly unilateral, with 50% occurring on the right side, 33%-35% on the left, and 10%-17% bilaterally. The pathogenesis is described as follows:
　　1. Gross examination:The tumor is a smooth, solid nodule on the surface; the section shows gray powder or light brown, and larger tumors may have hemorrhagic and necrotic foci; extensive hemorrhage, necrosis, or cystic areas often suggest the presence of choriocarcinoma or yolk sac tumor, while focal calcification may indicate the presence of malignant teratoma. When collecting specimens for external examination, careful observation should be made and specimens should be taken from areas with different gross morphologies.
　　2. Under the microscope:The tumor tissue is composed of large, round or polygonal cells arranged in sheets, islets, or beam-like structures; the cell diameter is 15-25μm, with clear boundaries between cells; the nuclei are large and round, with a clear nuclear membrane, showing vacuolation, prominent nucleoli, and eosinophilia; poorly differentiated tumor cells show marked atypicality. The stroma is composed of varying amounts of fibrous connective tissue and lymphocytes, occasionally forming lymphoid follicles with germinal centers; granulomatous nodules composed of histiocytes and multinucleated giant cells may sometimes be seen. When collecting specimens for external examination, careful observation should be made and specimens should be taken from different morphologically distinct areas.
　　3. Histochemistry:Similar to testicular seminoma and other germ cell tumors in the mediastinum and other sites, the tumor cells are identical to primordial germ cells in terms of histochemistry and ultrastructure. The cytoplasm of tumor cells is rich in glycogen, and they show positive reactions to PAS and alkaline phosphatase. Immunohistochemical staining shows that the cells are negative for cytokeratin (cytokeratin), which can be used to differentiate from embryonal carcinoma or yolk sac tumor; placental alkaline phosphatase (PLAP) is positive, which can be used to differentiate from other non-germ cell tumors.
　　4. Endocrinology:6% to 8% of dysgerminomas contain individual or small clusters of syncytiotrophoblasts, which form this tumor subtype. These syncytiotrophoblasts are HCG (chorionic gonadotropin) immunoreactive, and even may cause an increase in the patient's blood HCG level and yellowing of the residual ovarian stroma. Dysgerminomas containing syncytiotrophoblasts have similar biological behavior to pure dysgerminomas, while the malignancy of choriocarcinoma is higher.
　　5. Relationship between dysgerminoma and ambiguous sexual characteristics:In patients with ovarian dysgerminoma, because a few patients have ambiguous sexual characteristics, some authors have studied the relationship between dysgerminoma and ambiguous sexual characteristics.

　　Ovarian dysgerminoma often has lymph node metastasis due to its rapid growth, which is quite common. The metastatic pathways are mostly through lymphatic vessels and direct implantation, so the paraaortic lymph nodes and local pelvic organs are common sites of metastasis, followed by mediastinal lymph nodes, supraclavicular lymph nodes, and omentum. Individual cases may metastasize to the lung, liver, and brain.

　　Pelvic mass is the most common symptom of ovarian dysgerminoma. It is often accompanied by a feeling of bloating, and sometimes the tumor may twist, rupture, and bleed, causing acute abdominal pain. Ascites is relatively rare. Due to the rapid growth of the tumor, the course of the disease is relatively short. The menstrual and reproductive functions of most patients are normal, and only a few patients with primary amenorrhea or poor development of secondary sexual characteristics, such as a large clitoris and hirsutism, are observed in patients with primary gonadal dysgenesis.

　　There are currently no targeted preventive measures for ovarian dysgerminoma. High-risk groups should regularly undergo physical examinations, early detection, and early treatment, and pay attention to follow-up monitoring of tumor markers after treatment to prevent recurrence.

　　It is not uncommon for ovarian dysgerminoma to metastasize or recur. However, if chemotherapy is given routinely after the initial surgery, the recurrence rate is very low; and if there is recurrence, due to high sensitivity to radiotherapy and chemotherapy, the prognosis is usually good.

　　The diagnosis of ovarian dysgerminoma is not difficult, as it can be confirmed through laboratory tumor marker tests, auxiliary examinations such as B-ultrasound, CT, laparoscopy, and histopathological examination, combined with the patient's clinical manifestations and signs.

　　The dietary precautions for patients with ovarian dysgerminoma mainly include the following aspects:
　　1. Eat a light diet, and eat less or no high-dose lactose and excessive animal fat.
　　2. Do not have a preference and eat more foods rich in fiber, trace elements, and fiber-rich foods. Mushroom, soybean, fresh vegetables, winter mushroom, turtle, kelp, nori, oyster.
　　3. Eat more foods with antitumor effects. Cuttlefish, turtle, sea horse, dragon pearl tea, hawthorn.
　　4. Abdominal pain and distension: It is advisable to eat pork kidney, tangerine cake, myrica, hawthorn, walnut, chestnut.
　　5. Hemorrhage: It is advisable to eat goat blood, snails, squid, lotus root, shepherd's purse, mushrooms, stone ear, mussel, horse-tail grass, and hawthorn cake.
　　6. Infection: It is advisable to eat eels, clam, squid, lotus root, shepherd's purse, mushrooms, stone ear, mussel, and chive.
　　7. Do not eat smoked, moldy, or nitrite-containing foods.
　　8. Eat less fried, spicy, and preserved foods.
　　9. Do not smoke, do not drink excessively, and do not overeat.
　　10. In cases where cancer is in the late stage and the patient cannot eat, intravenous fluid administration or intravenous hyperalimentation can be provided.

　　The treatment of ovarian dysgerminoma mainly focuses on surgical treatment, supplemented by comprehensive treatment with radiotherapy and chemotherapy. The specific plan is as follows:
　　First, surgical treatment
　　1. Unilateral adnexectomy
　　The age of most patients with ovarian dysgerminoma is between 10 to 30 years old, with an average of 21 years. Therefore, the choice of surgical scope should try to preserve physiological and reproductive function, and unilateral adnexectomy should be performed. The prognosis of the unilateral adnexectomy group is not worse than that of the extensive surgery group.
　　In the following situations, careful consideration should be given to conservative surgery, and a decision should be made accordingly, or unilateral adnexectomy should not be considered.
　　① The patient is a hermaphrodite with an XY karyotype: To prevent the recurrence of tumor in the underdeveloped gonads on the opposite side, bilateral gonadectomy should be performed.
　　② Advanced stage tumor: When the pelvic implants and metastatic tumors have invaded the opposite ovary, unilateral adnexectomy is not considered. If the tumor has widespread metastasis in the aortic lymph nodes, pelvic lymph nodes, or other sites, but has not involved the opposite ovary and uterus, unilateral adnexectomy can also be chosen.
　　③ Bilateral tumors: Most dysgerminomas are unilateral, with only 10% to 20% being bilateral. Among these bilateral tumors, some appear grossly as unilateral tumors, but it is only when the opposite ovary is found to have a very small tumor through incision and exploration on the opposite side that this is discovered. Since dysgerminoma is a malignant tumor, once it becomes bilateral, bilateral adnexa and hysterectomy should be chosen. However, recent research has found that chemotherapy is very effective for dysgerminoma.
　　2. Lymph node dissection surgery:There is a divergence of opinion on whether to perform lymph node dissection surgery for ovarian dysgerminoma. Those in favor of the operation believe that the incidence of metastasis in dysgerminoma is high; while those against the operation argue that the tumor has a high sensitivity to chemotherapy. Since simple chemotherapy is very effective for metastatic dysgerminoma, there is no need to perform lymph node dissection surgery on possible lymph nodes that may not have metastasized or only have small metastases.
　　3. Second Comprehensive Pathological Staging Surgery:Some patients, when they were first operated on in other hospitals, only had the affected side of the adnexa removed and did not undergo a detailed exploratory pathological staging. Before finding the high sensitivity of the tumor to chemotherapy, such cases often underwent a second comprehensive pathological staging and lymph node dissection surgery. Now that it is known that cisplatin combined chemotherapy has a remarkable effect on dysgerminoma, a series of auxiliary examinations including CT, ultrasound, serum tumor markers, etc., can be carried out to fully understand the situation, and consider regular and effective chemotherapy without the need for staging exploratory surgery.
　　4. Surgical Treatment for Recurrent Tumors:If the site of tumor recurrence is in the pelvis, it can still be resected surgically.
　　2. Radiotherapy
　　Dysgerminoma is a tumor that is highly sensitive to radiation and can be cured by radiotherapy. After surgery, combined with radiotherapy, the survival rate can reach 100%. However, since most dysgerminomas occur in young patients, pelvic radiotherapy will affect physiological and reproductive functions, so its therapeutic effect is limited. But in the following situations, radiotherapy still has important value:
　　1. Patients already have children and the tumor is in the late stage, with many metastases or recurrence tumors. Radiotherapy can be supplemented after surgery.
　　2. Distant Metastasis and Recurrence: The effect of radiotherapy on distant metastasis or recurrence tumors has long been confirmed by many clinical practices. In the Mahammad group, there were 2 cases of extensive recurrence, 1 case of lung metastasis, and 1 case of large intraparenchymal liver metastasis, all of which were cured after radiotherapy.
　　3. Radiation Therapy to Preserve Fertility: To avoid the destructive effect of radiation therapy on the normal ovary, the opposite ovary can be covered during radiation therapy so that it is not irradiated.
　　3. Chemotherapy
　　In recent years, due to some very successful experiences with combined chemotherapy for dysgerminoma, chemotherapy may replace radiotherapy in the treatment status of dysgerminoma.
　　For the disease monitoring of ovarian dysgerminoma, although there is currently no relatively specific tumor marker to understand the condition and the effect of chemotherapy, serum LDH or NSE detection is still relatively sensitive for the disease monitoring of ovarian dysgerminoma.