Germogenigen cell tumors
Last reviewed: 23.04.2024
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Germogenigen cell tumors originate from pluripotent embryonic cells. Disturbance of the differentiation of these cells leads to the emergence of embryonic carcinoma and teratoma (embryonic line of differentiation) or choriocarcinoma and yolk sac tumor (extraembryonic pathway of differentiation). Violation of the development of unipotent primitive germ cells leads to the development of germinoma. The histological structure of these tumors is usually not characteristic of the anatomical region where they are located. Germogenogenous cell tumors can occur both in the genitals and outside them. Intrathan germ cell carcinomas are located along the median line, i.e. Along the migration path of primordial germ cells.
[Symptoms of germ cell carcinomas
The symptoms of germ cell neoplasms largely depend on localization. With ovarian tumors, pain syndrome can become the dominant one, and differential diagnosis with surgical diseases of the abdominal and pelvic organs is significantly hampered. When the vagina is affected, in some cases spotting is noted. Testicular tumors, as a rule, are painless and are often detected during external examination. Clinical manifestations of extragonadal tumors depend on the violation of the functions of nearby organs. When localization in the mediastinum is likely the occurrence of violations of breathing, coughing. The sacrococcygeal teratomas can cause disorders of the pelvic organs. When identifying any difficult to explain clinical manifestations, it is necessary to remember the possibility of a tumor disease.
Stages of germ cell carcinomas
The stage of the disease is determined by the prevalence of the tumor process and the completeness of surgical excision.
- Stage I. Limited tumor, excised within healthy tissues.
- Stage II. Microscopically incompletely removed tumor; tumor, germinating capsule, or the presence of micrometastases in regional lymph nodes.
- Stage III. Macroscopically incompletely removed tumor, involvement of regional lymph nodes (more than 2 cm in diameter), tumor cells in ascites or pleural fluid.
- Stage IV. Distant metastases.
In ovarian tumors, the division into the stages of the International Federation of Gynecology-Oncologists (FIGO) is widely used.
- Stage I. The tumor is confined to the ovaries:
- Ia - lesion of one ovary, capsule is intact, no ascites;
- lb - defeat of both ovaries, capsule is intact, no ascites;
- Ic - violation of the integrity of the capsule, tumor cells in peritoneal washings, tumor ascites.
- Stage II. The ovarian tumor is limited to the pelvic area:
- IIa - spread only to the uterus or fallopian tubes;
- IIb - spread to other organs of the small pelvis (bladder, rectum, vagina);
- IIc - spread to the pelvic organs in combination with the features described for step 1c.
- Stage III. The tumor extends beyond the small pelvis or there is a lesion of the lymph nodes:
- IIIa - microscopic tumor screenings outside the small pelvis;
- IIIb - tumor nodes less than 2 cm;
- IIIc - tumor nodes more than 2 cm or lymph node involvement.
- Stage IV. Distant organ damage, including the liver and / or pleura.
Classification
The histological classification of germ cell-cell tumors was developed by WHO in 1985.
- Tumors of one histological type.
- Germinoma (dysherminoma, seminoma).
- Spermatocytic seminoma.
- Embryonic cancer.
- Tumor of the yolk sac (endodermal sinus).
- Choriocarcinoma.
- Teratoma (mature, immature, with malignant transformation, with a one-sided orientation of differentiation).
- Tumors of more than one histological type.
Germogenic cell tumors account for less than 3% of all malignant neoplasms in children. At teenagers of 15-19 years their share makes 14%. Germinogenic tumors in different age groups have their biological characteristics.
For young children, extragonadal germ cell tumors are characteristic, most of which are teratomas. Teratomas contain elements of all three embryonic leaflets (ectoderm, endoderm and mesoderm). Mature teratoma consists of well-differentiated tissues. The immature terato is subdivided depending on the content of the immature neuroglial or blastema tissue into three histological subtypes. Teratoma - both mature and immature - can contain elements of various germ cell-cell tumors, and in rare cases - elements of other tumors (neuroblastoma, retinoblastoma). Most often teratomas are localized in the sacrococcygeal region.
In older children and adolescents, extragonadal germ cell carcinomas are most often located in the mediastinum.
Often germ cell carcinomas of the genital organs are combined with malformations (mixed and pure gonadal dysgenes, hermaphroditism, cryptorchidism, etc.).
Histologically, germ cell-derived testicular tumors in children are endodermal sinus tumors. Seminoles are typical for teenagers. Germogenogenous cell tumors of the ovaries are more often observed in girls during puberty. Histologically, they can be presented as a disgerminoma, a teratoma of varying degrees of maturity, a yolk sac tumor, or several histological types.
A characteristic cytogenetic abnormality is the isochromosome of the short arm of chromosome 12, found in 80% of germ cell-cell tumors. For germ cell-cell testicular tumors, chromosomal abnormalities are characteristic in the form of deletion of the short arm of chromosome 1, the long arm of chromosome 4 or 6, and also di- or tetraploidy. Semenomas often show aneuploidy.
In children with Klinefelter's syndrome (an increase in the number of X-chromosomes), the risk of germ cell-mediated tumor mediastinum is increased.
Diagnosis of germ cell carcinomas
A characteristic feature of germ cell-cell tumors is secretory activity. In the yolk sac tumor, an increase in the concentration of alpha-fetoprotein (AFP) is detected in the blood, and beta-chorionic gonadotropin (beta-XGT) in choriocarcinoma. Germinoma can also produce beta-XGT. These substances are used as markers for diagnosis of the disease and dynamic evaluation of the tumor process. Most germ cell carcinomas in children have elements of a yolk sac tumor, which causes an increase in the concentration of AFP. The dynamic definition of this marker makes it possible to evaluate the tumor response to therapy. It is important to remember that the concentration of AFP in children under 8 months is highly variable, the evaluation of the indicator should be carried out taking into account age-related changes.
What tests are needed?
Treatment of germ cell carcinomas
The results of treatment of malignant germ cell-cell tumors prior to the development of effective polychemotherapy regimens were extremely unsatisfactory. The overall three-year survival of patients with only surgical or radiotherapy was 15-20%. The introduction of chemotherapy led to an increase in the 5-year survival rate to 60-90%. Standard drugs for the treatment of germ cell-cell tumors are cisplatin, etoposide and bleomycin (REB scheme). Children under 16 years of age use the JEB scheme, where cisplatin has been replaced with carboplatin, which provides equal efficacy with less nephro- and ototoxicity (no direct comparison of the efficacy of JEB and PEB in randomized trials). Ifosfamide is also effective in the treatment of germ cell-cell tumors and is widely used in modern chemotherapy regimens.
What is the prognosis of germ cell-cell tumors?
The prognosis for germ cell carcinomas depends on the location of the neoplasm and the stage of the process, as well as on the patient's age (the younger the patient, the more favorable the prognosis) and the histological variant (in seminalomas, the prognosis is more favorable).
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