Hondroblastoma

Description:

Hondroblastoma  (chondroblastoma, Kodmen's tumor) - the tumor coming from chondroblasts; by the outward reminds accumulation of the differentiated cartilaginous tissue.

Hondroblastoma is rather rare tumor and is an intra joint benign tumor. The age of patients in the majority of observations fluctuates from 5 to 18 years. Men are surprised twice to a bowl of women.

Hondroblastoma's symptoms:

Hondroblastoma is in most cases localized in an epiphysis or a metaepiphysis of long tubular bones. More often than others the proximal joint ends of a humeral, femoral and tibial bone are surprised. At 20% of patients the tumor develops in flat or short tubular bones, is preferential in calcaneal and collision. Occasionally bones of a facial skull, including temporal are surprised.

The clinical symptomatology of a hondroblastoma differs in existence of the progressing next joint pains, their strengthening at an exercise stress and at night. Atrophies of muscles of an extremity, emergence of an inflammation in a joint are characteristic a prematurity of contractures.

The Kliniko-rentgenomorfologichesky comparison which is carried out at a hondroblastoma research allowed a number of authors to allocate the mixed tumor forms, and also a malignant hondroblastoma.

Hondroblastoma's reasons:

The macroscopic type of a hondroblastoma varies. Usually the tumor consists of granular fabric of yellowish-gray or brownish-gray color in which hemorrhages and aneurysmal cysts are defined. Also bluish-gray sites corresponding to a chondroid matrix are visible. Dot yellowish impregnations correspond to the centers of calcification or reactive bone formation. The corbel of the sclerosed bone tissue is determined by the periphery of a tumor.

Under a microscope this or that picture depends, mainly, on quantity of the chondroid matrix produced by tumor cells and also on prevalence of a necrosis, existence of aneurysmal cysts. Cellular polymorphism attracts attention. The greatest number of cells make honlroblasta with accurate contours in which the roundish or oval kernels surrounded with an enlightenment zone are defined. The kernels of cells split with deep invaginations and impressions. Nuclear chromatin looks melkoraspylenny or in the form of accumulations of irregular shape. The number of figures of a mitosis in a tumor is usually small, and they are defined only in 75% of cases. Only occasionally this number exceeds 4 on 10 fields of vision at big increase in a microscope. The atypical mitosis does not meet. The cellular atipizm is found only in 20 — 30% a chondroblast. Usually it is large cells of irregular shape with hyperchromic kernels. Apparently, their existence is not an adverse predictive sign. In some sites of border between chondroblasts vague, and the overall picture takes a sincytium form. Along with roundish elements in a tumor also spindle-shaped cells which form gnezdny accumulations meet or are evenly interspersed between typical cells. Also multinucleate cells which part are very similar to large osteoclasts meet. All above described cells give positive reaction to a SlOO-protein, a neyronspetsifichesky enolaza and vimentin.

Characteristic of the majority a chondroblast is formation of an eosinophilic chondroid matrix with small chondroblasts and not numerous mature chondrocytes. Sometimes it is difficult to find this matrix as it is disseminated in various departments of a tumor and its volume is small. In some tumors the miksoidny stroma decides on spindle-shaped or star-shaped cells. In the thickness of a chondroid matrix or around cells of a tumor deposits of salts of calcium are visible. Especially often such calcification meets in dystrophic the changed or nekrotizirovanny tumors.

Hondroblastoma's treatment:

Method of the choice of treatment of a hondroblastoma is surgical intervention. The resection of a bone which depending on the sizes of the pathological center allows to make an oncotomy the uniform block within healthy fabrics is carried out regional, circumarticular or segmented and to keep a functional extremity.

Some patients within 3 years after that have a recurrence for which treatment the curettage or a resection of a tumor is also used. About 1% a chondroblast differs in aggressive local growth and metastasizes in lungs, and metastasises can come to light many years later after detection of primary node. Some hondroblastoma burgeon in surrounding soft tissues, but at the same time do not metastasize. Cases of a malignancy of this new growth after radiation therapy with formation fibro - or osteosarcomas are described.