Osteosarcoma

Description:

Osteosarcoma - sarcoma which malignant cells come from a bone tissue and produce this fabric. In some of these tumors hondroblastichesky or fibroblastichesky components dominate. Radiological it is subdivided on osteolytic, the osteoplastic (sclerous) and mixed forms.

Osteosarcoma - extremely malignant new growth. Arising directly from bone elements, it is characterized by a rapid current and tendency early to give metastasises.

The osteosarcoma is observed at any age, but about 65% of all cases fall from 10 to 30 years, and most often development of sarcoma is noted at the end of puberty. Men are surprised twice more often than women. Favourite localization are long tubular bones; on a share of flat and short bones no more one fifth part of all osteosarcomas falls. Bones of the lower extremities 5-6 times more often are surprised, than bones of upper extremities, and 80% of all tumors of the lower extremities nest in area of a knee joint. First place on frequency is won by a hip on which share a half of all osteosarcomas falls, then the tibial bone, humeral, haunch bones, fibular, a shoulder girdle, an ulna follows. The beam bone where the giant-cell tumor is so often observed, exclusively seldom gives growth of an osteosarcoma. Almost never the osteosarcoma proceeds from a patella. Damage of a skull takes place mainly at children's age, and also in old age as a complication of the disfiguring osteodystrophy. Typical localization of an osteosarcoma in long tubular bones is meta - the epiphyseal end, and at children and young men, before a synostosis, - a bone metaphysis. In a femur ordinary distal end is surprised, but about 10% of osteosarcomas of a hip nest in a diaphysis and leave metaphyses untouched. In a tibial bone the osteosarcoma only in one case from ten is located in the distal end - as the typical place serves the proximal medial condyle. The same typical place for a humeral bone is the area of a roughness of a deltoid muscle.

Osteosarcoma symptoms:

The main clinical sign of an osteosarcoma is pain over the struck area. Pain is stupid, constant with gradual increase of intensity. A characteristic symptom are night pains. 3/4 patients can have a myagkotkanny component. The extremity is increased in volume, often looks edematous. Pain and increase in volume lead to dysfunction. Duration of the anamnesis averages 3 months.

Defeat of metaphyses of long tubular bones is characteristic. The most frequent localization (about 50% of cases) - area of a knee joint - a distal part of a hip and a proximal part of a tibial bone. Often also a proximal part of a humeral bone and femur, and an average third of a femur is surprised. Damage of flat bones, especially a basin at children's age meets less than in 10% of cases.

The osteosarcoma possesses a huge tendency to development of hematogenous metastasises. By the time of establishment of the diagnosis of 10%-20% of patients already have the macrometastasises in lungs revealed radiological. But already about 80% of patients by the time of establishment of the diagnosis have the micrometastasises in lungs which are not revealed radiological, but seen at a computer tomography. As bones have no the developed lymphatic system, early distribution of an osteosarcoma to regional lymph nodes meets seldom, but if it takes place, then is a bad predictive sign. Other zones of innidiation - bones, a pleura, a pericardium, kidneys, TsNS.

The osteosarcoma has also local aggressive growth, can extend to an epiphysis and a nearby joint (knee and humeral joints most often are surprised), extending along intra joint structures, through a joint cartilage, through perikapsulyarny space, or, in the direct way, owing to a pathological change and to form the centers, not adjacent to it, - satellites - "skip" - metastasises.

Disease
The beginning of a disease not always manages to be defined precisely. Not clear dull aches develop near a joint as initially the tumor is localized most often near metafizarny department of a tubular bone. There is joint pain without objective signs of an exudate in it, often after an injury in the past. In process of expansion of borders of a tumor and involvement in process of the next fabrics of pain amplify. Appear a clear thickening of metadiaphyseal department of a bone, the expressed pastosity of fabrics, the venous network of skin clearly is defined. By this time there is a contracture in a joint, lameness increases. At a palpation - sharp pain. The severe night pains which are not removed by aspirin, are not connected with function of an extremity and not ceasing even when fixing in gypsum. The tumor promptly extends on the next fabrics, quickly fills the marrowy channel, sprouts muscles, very much early gives extensive hematogenous metastasises, especially in lungs, a brain; metastasises in a bone are extremely rare.

Rare options of an osteosarcoma.
Telangiectatic - radiological reminds an anevrizmalny bone cyst and a giant-cell tumor, is shown by existence of the lytic centers with poorly expressed sclerosis. The course of a disease and the answer to chemotherapy practically does not differ from standard options of an osteosarcoma.

Yukstakortikalny (paraossalny) - proceeds from a bast layer of a bone, tumoral fabric can surround a bone from all directions, but as a rule, does not get into the marrowy canal. The Myagkotkanny component is absent therefore radiological it is difficult to distinguish a tumor from osteoid. As a rule, this tumor of low degree of a zlokachestvennost, flows slowly, almost does not give metastasises. Nevertheless, the paraossalny osteosarcoma demands adequate surgical treatment, practically same as standard options of a tumor. Otherwise this tumor recurs and at the same time the tumoral component changes zlokachestvennost degree for higher, as defines the forecast of a disease.

Periossalny - also, as well as paraossalny, is located on the surface of a bone and has a similar current. The tumor has a myagkotkanny component, but does not get into the marrowy canal.

Intraossalny tumors with low degree of a zlokachestvennost, are well differentiated, with the minimum cellular atypia, can be regarded as a benign tumor. But they also tend to local recuring with change of a tumoral component on more malignant option.

Multifocal - is shown in the form of the multiple centers in the bones similar at each other. Not it is clear up to the end, whether they appear at once, or there is bystry innidiation from one center. Forecast of a disease fatal.

Ekstraskeletny osteosarcoma - the rare malignant tumor which is characterized by products of osteoid or a bone tissue, sometimes together with cartilaginous tissue - in soft tissues, most often, the lower extremities. But also defeats of other areas, such as a throat, kidneys, a gullet, intestines, a liver, heart, a bladder, etc. meet. The forecast of a disease remains bad, sensitivity to chemotherapy very low. The diagnosis of an ekstraskeletny osteosarcoma can be established only after an exception of existence of the bone centers of a tumor.

The small-celled osteosarcoma - a high-malignant tumor, on the morphological structure differs from other options that defines also its name. Most often this tumor is localized in a femur. The small-celled osteosarcoma (the differential diagnosis with other small-celled tumors) surely produces osteoid.

The basin osteosarcoma - despite improvement of the general survival at an osteosarcoma, has very bad forecast. The tumor is characterized by bystry and wide circulation in fabric and along them as, owing to an anatomic structure of a basin, does not meet considerable fascial and anatomic barriers on the way.

Stadirovaniye of an osteosarcoma (Enneking WF, Spanier SS, Goodman MA, 1980, USA)

IA stage - The high-differentiated tumor. The center is limited by the natural barrier interfering spread of a tumor. Lack of metastasises

IB stage - The high-differentiated tumor. The center extends out of limits of a natural barrier. Lack of metastasises

IIA stage - The low-differentiated tumor. The center is limited by a natural barrier. Lack of metastasises.

IIB stage - The low-differentiated tumor. The center extends out of limits of a natural barrier. Lack of metastasises.

Stage of III - Existence of the regional and remote metastasises, regardless of tumor differentiation degree

Osteosarcoma reasons:

Development of a tumor has some communication with rapid growth of a bone. The children suffering from an osteosarcoma, as a rule, are higher growth, in comparison with age norm, and the disease affects the most quickly growing parts of a skeleton.

Development of bone tumors often is associated with an injury, but, rather an injury draws attention of the doctor and forces to conduct X-ray inspection

The only agent of external environment famous as a stimulator of bone sarcomas - ionizing radiation. And the interval between influence of this factor and emergence of an osteosarcoma can be from 4 to 40 years (on average 12 - 16 years).

Among 2% having Pedzhet's disease get sick with an osteosarcoma, it is frequent with multiple damage of bones.

Existence of benign tumors of bones (an osteochondroma, an enchondroma, etc.) increases risk of a disease of an osteosarcoma.

Among the patients cured of a retinoblastoma, 50% of secondary tumors are the share of an osteosarcoma (a retinoblastoma - the tumor which often have hereditary character), and at both diseases identical changes in the 13th couple of chromosomes meet.

Treatment of the Osteosarcoma:

Treatment of an osteosarcoma includes the following stages:
1. Preoperative chemotherapy for suppression of micrometastasises in lungs, reduction of the sizes of primary center of an opukholeobrazovaniye and assessment of the histologic answer of a tumor to chemotherapy that defines a further technique of treatment. For treatment of an osteosarcoma in the present the following drugs are used: high-dose methotrexate, Adriblastinum, ифосфамид, platinum drugs, (карбоплатин, Cisplatinum), этопозид.

2. Obligatory operation. If earlier resorted to extensive operation, the amputation of all extremity often including, then now are limited to a conservative surgery. At the same time delete only parts of a bone with replacement it on an implant from plastic, metal or a cadaveric bone. Refuse organ-preserving operation when the tumor sprouts a neurovascular bunch if there was a pathological change, and also at the big sizes of a tumor and its germination of soft tissues. Existence of metastasises is not a contraindication to organ-preserving operation. Large metastasises in lungs are also removed surgically.

3. Postoperative chemotherapy taking into account results of preoperative chemotherapy.

Radiation therapy for treatment is ineffective owing to the fact that cells of an osteosarcoma are insensitive to ionizing radiation. Radiation therapy is carried out if for any reason operation is impossible.