Periosteal chondroma represents a distinctive benign cartilage tumor, apparently originating in the periosteum. This discussion is based upon experience with six cases, all but one of which were observed within a period of a year. We have encountered the tumor, thus far, on hand and foot bones, as well as on large limb bones, such as the tibia and humerus. It is a slowly growing neoplasm of comparatively small size, which develops within and beneath the periosteal connective tissue and characteristically erodes and induces appreciable sclerosis of the contiguous cortical bone. As such, its roentgenographic appearance has a certain distinctiveness which enables one to recognize the lesion, if he is familiar with it, and clearly to distinguish it from osteochondroma, as well as from solitary enchondroma.
The tumor may develop in children, as well as in adults. The symptoms usually referable to it are pain, gradual swelling, and local tenderness. The duration of symptoms in the cases observed ranged from a few months to ten years. Clinically, one finds a firm, generally small, slightly tender tumor which, if located near a joint, may produce some limitation of motion. At surgery, one observes a rubbery, firm, lobulated cartilage tumor, adherent to the periosteum. This is found to be partially nestled within the gouged-out underlying cortex, which is extremely resistant to curettage.
Whatever its localization, the tumor is composed characteristically of lobules of hyaline cartilage. Although its cartilage-cell nests are likely to be more compact then those of an enchondroma and its cell nuclei somewhat plumper, these cytological features are not to be construed as indications of aggressiveness or malignancy.
The treatment recommended in most instances is conservative surgical extirpation and curettement of the eroded, sclerotized cortical base. Block excision is feasible if the tumor has involved a long limb bone and is substantially larger than it is on a finger phalanx, for example. The results of treatment by either method were uniformly satisfactory. Although none of the patients covered by this report have been followed for more than three years and most of them for only a year or two, there has been no indication of any tendency to local recurrence following surgical extirpation.