Nearly 8 years after initial presentation, plain radiographs showed closed physes and partially ossified bone masses (Figures 2A-2C). The metacarpal lesion measured 3.2×1.5 cm, and the cortex appeared thickened and regular. The proximal phalanx lesion had a thickened cortex without periosteal reaction, and the middle phalanx lesion appeared to be completely healed. The patient has been asymptomatic for many years, and she has retained complete function of her left hand without any growth retardation, angular deformity, or pathologic fracture. A small but potential risk of malignant transformation was discussed with the patient and her family, as was the need for lifetime follow-up. We intend to follow the enchondromas clinically and radiographically every 2 years and obtain new radiographs if the mass presents with new clinical findings, such as enlargement or pain, for surveillance of tumor transformation. If the patient desired or symptoms developed, curettage and bone grafting would be offered, and the surgical tissue would be sent for pathologic analysis. A bone scan that was obtained at the request of the patient, when she was 21 years old, showed no other sites of disease besides the fingers.
Discussion
Multiple enchondromatosis was first described by Ollier at the turn of the 19th century and has been estimated to affect one in every 100,000 persons.1 The low prevalence and variable manifestations of Ollier disease lead clinicians to handle the disease and its complications, namely skeletal deformity and malignant transformation, on a case-by-case approach. Additionally, the prognosis of Ollier disease with malignant transformation is quite variable, with studies reporting the estimated incidence as 5% to 50%.7 Muramatsu and colleagues6 reported that the occurrence of malignant transformation of multiple enchondromas limited to the bones of the hand was extremely rare, with only 12 cases of malignant transformation. Enchondromas of the pelvis, scapula, and long bones of the extremities have increased risks and rates of secondary transformation to chondrosarcoma.8
A recent large European multicenter retrospective study investigating the clinical characteristics and behavior of enchondromas in 144 patients with Ollier disease has provided new information regarding this rare disease.7 Verdegaal and colleagues7 divided patients into 3 categories depending on their distribution of enchondromas. The development of chondrosarcoma was notably different between individuals with enchondromas limited to the small bones of the hands and feet (15%, group I) versus individuals with enchondromas limited to the long bones and flat bones (43%, group II) or individuals with enchondromas of the short, long, and flat bones (46%, group III).7 The only location found to be statistically significant for the development of chondrosarcoma was the pelvis.
The clinical findings associated with risk of malignant transformation of enchondromas are increasing size of the lesion and onset of pain and tenderness. Dahlin and Salvador9 reported that only 60% of patients with chondrosarcoma of the hand experience pain. The absence of pain may lead to a delay in patient presentation to the clinician.5,6 Radiographic findings of malignant transformation include the classic features of temporal increases in the lesion’s size after skeletal maturity and cortical destruction associated with soft-tissue invasion. However, both findings are nonspecific for differentiating enchondromas from grade 1 chondrosarcomas as described by Geirnaerdt and colleagues.10
Sassoon and colleagues11 reported on a series of hand enchondromas treated operatively. Subgroup analysis between pathologic fractures treated primarily or in delayed fashion showed similar outcomes for achieving full motion and similar number of complications; however, they noted that the delayed group required 7 more weeks of immobilization. Additionally, review of the whole series showed 1 episode of metacarpal shortening and 1 occurrence of angular malalignment. In our patient, we were concerned about introducing an iatrogenic cosmetic deformity, and we believed a pathologic fracture could be managed expectantly. Overall, patients without pathologic fracture treated surgically experienced a complication rate of 12%, whereas patients with a fracture had a complication rate of 20%.11 The majority of patients with multiple enchondromatosis treated with surgical curettage and grafting had successful outcomes, with 86% of patients regaining full motion, but the recurrence rate was 21%.11 Patients with expansile lesions regained less motion than patients with nonexpansile lesions. There was a single lesion believed preoperatively to be an enchondroma, but it underwent malignant transformation, as confirmed on intraoperative pathology. This patient had Maffucci syndrome and was treated with an amputation through the metacarpophalangeal joint.
There are 3 options for treating hand enchondromas: observation, curettage alone, or curettage with bone grafting. There is no consensus about conservative management, timing of intervention, or risk of pathologic fracture. Each patient is treated individually with attention to reason for presentation, number of lesions, associated pain, deformity, or pathologic fracture. Operative criteria include high risk of pathologic fracture based on location of enchondroma, cortical thinning, and previous pathologic fracture with resulting angular deformity. Nonoperative management may increase the risk of pathologic fracture, particularly in patients involved in aggressive contact sports, but the physician may offer protective splinting or counsel the patient on activity modification. Our case provides a study of the natural history of multiple enchondromatosis and shows mild increases in the lesions’ sizes during the 8-year follow-up. This was an expected finding given the patient’s immature skeleton. The lesions’ cortices continued to ossify after the physes closed and now provides an excellent comparison for the identification of future malignant changes.
