Enchondroma

An enchondroma or chondroma is a common, benign and tumor -derived from cartilage tissue. It is found mostly in the 20 to 40 years of age in the medullary cavity of the long bones. Multiple enchondromas are found in different syndromes, in which case there is the risk of degeneration.

• 6.1 Maffucci syndrome
• 6.2 Ollier syndrome

Clinic

The lesions are painless and slow growing normally. In general, there are incidental findings at a x-ray examination. Rarely fall enchondromata on by pathological fractures or pain. Then malignancy exclusion is mandatory. For multiple enchondromas a syndrome must be excluded, as syndromic enchondromata can degenerate (see syndrome).

Localization

Enchondromas are found for the major part in the long bones of the fingers ( 60%). More rarely, enchondromata find in the field of foot bones, the femur, the humerus and the iliac wing.

The localization affects the probability of malignant degeneration. To show coming near lesions a higher probability degeneration ( s.Chondrosarkom ). In particular enchondromata of the basin should be removed very carefully.

Pathology

Macroscopically it is in most cases to gray-blue tumor nodules that are usually less than three inches tall and lobulated. These are usually in the medullary cavity of the long bones. Histologically, at enchondromata to mature cartilage with cartilage - typical hyaline matrix and histologically benign cartilage cells ( chondrocytes). The tumor margin is usually a endochondral ossification. Also the tumor center may calcify after necrosis. The surrounding bone tissue is displaced in the rule, but not destroyed.

In etiological respect one now believes that it is embryonic remnants of the growth plate. Healing after fractures may prevent the neoplastic nature of some enchondromas.

Diagnostics

The diagnosis of enchondroma can usually be made relatively safe with imaging methods. Often in classical phenomena ranging from the X-ray image to the primary diagnosis and follow-up. In unclear cases, the cross-sectional imaging of computed tomography and especially magnetic resonance imaging help further crucial. In addition to the primary diagnosis of the imaging techniques has the task to identify early in the course of a possible malignant transformation of an enchondroma to chondrosarcoma. This can sometimes be difficult. The most important clinical evidence of degeneration is the occurrence of pain.

X-ray

Radiographically, the classic enchondroma as the bone axis elongated, ovoid lesion centrally in the medullary cavity of long bones represents however eccentric position does not preclude an enchondroma. The center of the lesion is usually in the metaphysis or in the distal diaphysis of a long bone. A small or short bone can be completely filled. Typical Enchondromas is a thinning of the cortex of the bone from the inside, the so-called scalloping and, in the case of an expansion over the volume of bone, the formation of the cortex ( neocortex ). A periosteal reaction is, however, almost never observed. The appearance of an enchondroma is further characterized mainly by widely varying degree of calcification of the primary cartilaginous tumor matrix: this can be point-like, ring - and arc- shaped ( " rings and arcs " ) and flaky. Often impress the image of popcorn -like. The calcifications are more common and more pronounced in the long bones, while the lesions in the small bones of the fingers and feet calcify less. The X-ray image reliably detected only the calcifications and the scalloping, so that the true extent of an only slightly calcified enchondroma may be underestimated by this method. Disappearance of previously calcified areas within an enchondroma in the course must be interpreted as an indication of degeneration.

Computed tomography ( CT)

The value of CT mainly refers to the superposition-free representation, so that even the finest matrix calcification can be detected. The structure of the cortex can be better assessed.

Magnetic resonance imaging ( MRI)

Since enchondromata consist of 95% hyaline cartilage matrix, the enchondroma provides MRI on T2- weighted sequences homogeneously bright dar. This is especially the typical pattern of many enchondromata ( " popcorn -like", " rings and arcs " ) out clearly. In addition, MRI is the best method to assess the extent of enchondroma exactly. This is for planning before surgical removal of crucial importance.

Scintigraphy

Scintigraphy enrich the lesions usually, so that the distinction from a malignancy can be difficult. However, the type of storage is lower than in malignant osseous processes. Also found in the 3-phase scintigraphy no increased perfusion. The storage is dependent on the Ossifizierungsgrad, therefore a comparison with the radiographic findings is required.

Biopsy

The biopsy of the lesion is usually necessary when a malignant tumor can not be excluded. If possible, the entire tumor should be excised, as well as malignant and gutdifferenzierte chondrosarcomas may contain areas that histologically resemble a enchondroma.

Therapy

In typical and benign radiograph and absence of clinical symptoms is a therapy not absolutely necessary (En Bloc Excision or curettage ). Can not be safely ruled out a malignant tumor, the tumor should be removed or monitored closely. Symptomatic lesions are surgically excised in general. Enchondromata of the rare locations also require thorough investigation.

Syndromes

Syndromes associated with multiple enchondromas are called Enchondromatosen.

Maffucci syndrome

In Maffucci syndrome ( syn. Dyschondroplasia haemangiomatosa ) there are multiple, asymmetric enchondromata va the limbs in combination with multiple hemangiomas of the skin and internal organs. This enchondromata often degenerate. Patients also tend to develop other malignant tumors (eg, angiosarcoma ). It is a complex developmental disorder of the mesoderm.

Ollier 's syndrome

When Ollier syndrome ( syn. Hemichondrodysplasia type Ollier ), it is a half-page Enchondromatosis multiple long bone. This leads to growth disorders and fractures. The cause is unknown.

The multiple enchondromas tend in old age often (about 25-30 % ) to a degeneracy (see chondrosarcoma ).

Differential Diagnosis

After radiological criteria comes - in elderly patients and metaphyseal involvement of long bones - only the chondrosarcoma in question.

Swell

• J.Freyschmit, H.Ostertag, G. Jundt: bone tumors. Springer 2003, ISBN 3-540-40364-7
• C.Adler: Knochenkrankeiten: Springer 1983, ISBN 3-540-62836-3