Screening for sarcomatous degeneration in ollier disease is a challenge.
Regular follow-up and examinations are the most important screening tool. Radiographic exams should only be used as an adjunct to the clinicians judgment.
Patient's with enchondromatosis can easily be separated into high risk and a low risk groups. Low risk includes patient's with few lesions, small lesions, lesions confined to one area of the distal extremity either upper or lower, et cetera. High-risk patient's include patients with large numbers of lesions, large sized lesions, and large lesions in the pelvis or proximal long bones.
There appears to be some agreement amongst those who have studied this issue that the volume of abnormal tissue is related to the overall risk of malignant degeneration.
Beginning with the low risk patients: I think these patients probably do not need any form of screening. They should be informed about the risk, they should be informed about the symptoms that might present themselves should they develop a change, and then they should be encouraged to examine themselves or have a friend or family member examine them for change. In the absence of change I think no intervention is necessary.
Next for the high-risk patient. There is no substitute for repeat examination. I recommend that these patients be examined by someone who is able to follow them in a longitudinal fashion and note any new developments. This could be an orthopedic oncologist, a physician's assistant, a clinical nurse practitioner, or someone who has the interest and knowledge to follow these patients. Examination and listening to the patient's story about the symptoms that may have developed is just as sensitive and more specific, in my mind, as radiographic screening.
Finally, radiographic screening. This is a little bit of a knotty problem, because the more intensively one screens with radiographs the more radiation, the more the cost, or both. With more intensive screening, the risk of finding a minimal change increases. In today's health care environment, any type of worrisome minimal change on x-ray, and MRI, or any study, often leads to maximal intervention, especially when the potential for cancer is concerned. Many of these interventions are not warranted but basically the health care team is forced to act to reduce risk.
So having said all of that, I recommend the following: First of all when a high risk patient is first seen, a comprehensive evaluation of the skeletal lesions is made. Old radiographs that may show the status of the lesions in the past are very valuable here because they can identify right from the outset any lesions that have already become problematic and need to be further evaluated.
Assuming that after the initial comprehensive evaluation no worrisome lesions that need further investigation are identified, then I recommend physical examination and interview screening on a yearly basis for high-risk enchondromatosis patients. I do not recommend any routine radiographics or screening studies, in the absence of new symptoms. If new symptoms have occurred, then plain radiographs of the affected area might be enough to rule out problems. If plain radiographs are not enough to fully characterize the lesion in question, an MRI is the best next step. I sometimes use serial MRIs to evaluate large deep lesions that have a lot of unmineralized cartilage. The patient will have an MRI at the first evaluation, and then in about 4 months and again in 8 months. It is essential that the MRI be done at the same location each time with the same technique and preferably by the same radiologist. Any change is noted. The literature has several publications on how to distinguish worrisome from non-worrisome lesions. The only true sign of a problem is progressive change.
