Sclerotic lesion

My knee xrays find a sclerotic lesion in the distal right femoral diaphysis possibly enchondroma.
I have constant deep down bone pain in my legs and hip. Where is this exaclty in reference to my knee anyway? I talked to my Doctor and he is only referring me for a MRI of the one knee, nothing more. He also said I had a bone spur. What?????????
First off a bone spur and sclerotic lesion aren't remotely close are they?
Secondly all that I have read about ths finding says it needs closer diangostics and possible biopsy.
What to do? What to do?

[Sumer K Sethi, MD]

Most often, enchondromas are of no consequence and patients are asymptomatic. Enchondromas are benign cartilaginous neoplasms that are usually solitary lesions in intramedullary bone. The primary significant factors of enchondromas are related to their complications, most notably pathologic fracture, and a small incidence of malignant transformation. On basis on x-ray findings there are two differential diagnosis, one is enchondroma other is bone infarct. Following MRI confirmation follow up is recommended.
MRI findings may be useful in distinguishing enchondromas in the long bones from bone infarcts. Typically, bone infarcts are encapsulated by a serpiginous rind of decreased signal intensity on T1- and T2-weighted images. Frequently, this rind is subtended by a high-signal-intensity line. This finding has been called the double-line sign. Conversely, enchondromas tend to have lobulated borders with a cluster of numerous tiny locules of high-signal-intensity foci on T2-weighted images that appear to coalesce.