Hondroblastoma – a rare benign tumor which is usually formed on the articulate ends of bones. Comes from hondroblast and on the structure reminds rather mature cartilaginous tissue. Slow growth and a favorable current is usually noted, however in literature separate cases of an ozlokachestvleniye and initially malignant current hondroblasty are described. As a rule, develops at children's or youthful age (10-25 years, the greatest number of cases is the share of age of 10-18 years), but can arise also at people of the senior age groups. It is shown by pain and a swelling in a joint. The radiological picture can be nonspecific therefore for specification of the diagnosis other additional methods of a research quite often are required. Treatment surgical in a planned order. The forecast is usually favorable.
Hondroblastoma – the benign tumor which is formed of cells of cartilaginous tissue. It is usually localized in the field of epifiz of long tubular bones. First place on prevalence is won distalny a femur, by the second – proximal a tibial bone, the third – proximal a humeral bone. Less often hondroblastoma are found in the field of a proximal epifiz of a femur, bones of a basin and bones of foot (especially – calcaneal and collision). Also development cases hondroblasty in a breast, edges, a shovel, a backbone, a patella, bones of a forearm, a clavicle, phalanxes of fingers, bones of a wrist, the lower jaw and bones of the arch of a skull are described.
The greatest number of cases comes to light on the second decade of life, less often the disease develops at mature and advanced age. In various age groups of a hondroblastom makes from 1% to 3-4% of cases of total number of benign tumors. Men suffer 1,5-2 times more often than women.
Researchers in the field of orthopedics and traumatology allocate good-quality and malignant forms of a hondroblastoma. The good-quality form can be typical or mixed. In the latter case along with cells of cartilaginous tissue it has unusual structure or contains the cages characteristic of other benign tumors. The following options are possible:
- Hondroblastoma from osteoblastoklastomy.
- Hondroblastoma with hondromiksoidny fibroma.
- Hondromny form of a hondroblastoma.
- Cystous form of a hondroblastoma.
Malignant forms of a hondroblastoma are subdivided on:
- Ozlokachestvlenny hondroblastoma. At the same time the hondroblastoma can be transformed to hondroblastichesky osteogene sarcoma or hondrosarky.
- Initially malignant hondroblastoma.
- Light-cellular hondrosarkoma.
All malignant forms of a hondroblastoma in the sum make about 7% of total number of cases of a disease, from them 4,4% fall on a malignization of initially benign tumor. In most cases the ozlokachestvleniye occurs after several recurrence of a good-quality form of a hondroblastoma which is result of its incomplete removal.
At a good-quality current of a hondroblastoma at early stages there are unpleasant feelings in a joint which can remain for several months or even years. In the subsequent the progressing pain syndrome develops. Pains amplify at night and during physical activity. Restriction of movements with development of a contracture and a moderate atrophy of muscles is possible. Pathological changes with which patients can address the traumatologist are in some cases observed. During survey the swelling in a joint, pains is noted at a palpation and the movements. At defeat of disteel department of a femur at some patients the small exudate in a knee joint is defined.
For malignant hondroblasty quickly progressing current with the hypostasis and deformation of the struck area expressed by a pain syndrome and high probability of developing of pathological fractures is characteristic.
Diagnostics of a hondroblastoma
On roentgenograms the limited enlightenment of ovoid or spherical shape which is usually located on a side surface of an epifiz comes to light. At distribution to a tendinous plate its final fracture is noted. The pathological center has equal, accurate contours. On edge of the center moderately expressed sclerosis rim comes to light. The Kortikalny layer of a bone is blown a little up, periostalny stratifications in the field of a metafiz of a bone can come to light. Approximately in half of cases in the field of the center more or less expressed krapchatost caused by adjournment of lime in hondroblastoma fabric is noted.
At localization of a hondroblastoma in the field of border between epifizy and metafizy the radiological picture can remind inflammatory process (Brodie's abscess). At the hondroblastoma mixed with a gigantokletochny tumor the center settles down in a bone, almost completely occupying it in the cross direction and causing swelling and thinning of a kortikalny layer on a bone circle. At a hondromny form of a hondroblastoma the big centers of calcification come to light, at cystous – the multiple cysts divided by partitions.
The extensive centers of destruction with destruction of a kortikalny layer of a bone are characteristic of initially malignant and ozlokachestvlenny hondroblastoma. In certain cases the hondroblastoma radiological reminds a gigantokletochny tumor of a bone, hondrosarky or osteogene sarcoma therefore specification of the diagnosis requires carrying out additional researches – trepanobiopsiya or radio indications.
Macroscopically the hondroblastoma represents the similar to a cartilage reddish-brown or gray easily crumbling fabric with an impregnation of more dense calcific sites. At a histologic research densely located same roundish and polygonal unripe cells of cartilaginous tissue with light bubbly kernels by the form reminding a picture of "cobblestone road" come to light. Among these cages the large or small centers of a kaltsifikation settle down. Sites of calcification usually of a nekrotizirovana, near the centers of a necrosis can come to light hemorrhages and be found multinuclear huge cages.
Differential diagnostics is carried out with an enkhondromy, light-cellular hondrosarkomy, gigantokletochny tumor of a bone, hondromiksoidny fibroma, a bone cyst, gistiotsitozy Langergans's cells, and hondroblastichesky option of osteosarcoma. In doubtful cases the final diagnosis is established on the basis of results of a histologic research of a bioptat.
Treatment of a hondroblastoma
The surgery providing full removal of a tumor as when leaving even of the small site of the changed fabric of a hondroblastom usually recurs is shown. Surgical intervention is carried out in a planned order, the volume of operation depends on the size and localization of a hondroblastoma. At small hondroblastoma the regional resection with the subsequent replacement of defect with own bone of the patient or allotransplantaty is carried out. If the tumor is in close proximity to a subkhondralny plate, after removal of pathologically changed fabric electrothermic coagulation of this zone can be required.
At hondroblastoma of the big sizes which are followed by considerable destruction of the articulate end of a bone the resection of the articulate end with defect replacement with an endoprosthesis or a similar articulate articulate allotransplantat is carried out. At an ozlokachestvleniye and initially malignant hondroblastoma expanded surgery is carried out. Often mutilating operations – amputation and an exarticulation are required.
Radiation at a hondroblastoma is not shown neither at a good-quality current, nor in case of a malignization as the benign tumor after radiation can regenerate in malignant, and at a malignant hondroblastoma this method of treatment is inefficient. The forecast at a good-quality hondroblastoma favorable, at malignant – adverse, however small quantity of the described cases of initially malignant and ozlokachestvlenny hondroblastoma does not give the chance rather authentically to predict a current and an outcome of a disease.