Background: Enchondromas originating in the epiphyses of long bones
are rare. The purpose of the present study was to evaluate the prevalence as
well as the radiographic and clinical characteristics of epiphyseal
enchondromas among patients who had been referred to the Armed Forces
Institute of Pathology and Walter Reed Army Medical Center.
Methods: We performed a retrospective review of 761 patients who had
been referred to our two institutions over an approximately fifty-five-year
period and who received a final diagnosis of enchondroma. All lesions had been
biopsied, and the pathological diagnosis had been confirmed. Lesions of the
hands, feet, or axial skeleton (253 patients) as well as lesions that appeared
to originate in the metaphysis or diaphysis (475 patients) were excluded. Only
enchondromas of the long bones that originated in the epiphysis were analyzed.
The study group included thirty-three patients (twenty male patients and
thirteen female patients) with a mean age of 26.7 years, including eleven
patients with open physes. We performed additional descriptive analyses with
regard to patient age, gender, lesion location, clinical presentation, and
treatment as well as an extensive radiographic analysis.
Results: The most common locations were the proximal part of the
humerus (ten lesions; 30%) and the distal part of the femur (six lesions;
18%). The most common presenting symptom was pain (twenty-three patients).
Radiographic analysis demonstrated extensive matrix mineralization in
association with twenty-three lesions. Twenty-eight of the thirty-three
lesions were geographically well defined; of these, twenty-one had sclerotic
borders, and seven did not. Although all lesions were centered and were
predominantly located within the epiphysis, twenty of the thirty-three lesions
demonstrated radiographic evidence of metaphyseal extension, including four of
the eleven lesions in patients with open physes. Twenty-four lesions extended
into the subchondral bone. The mean size of the thirty-three enchondromas in
greatest radiographic dimension was 2.7 cm (range, 1.1 to 4.9 cm). Twenty-six
of the thirty-three lesions were amenable to surgical treatment with curettage
with or without bone-grafting, with only one recurrence. With the limited
follow-up available, no lesion underwent sarcomatous degeneration.
Conclusions: Epiphyseal enchondromas are rare lesions. Although
their biologic behavior appears to mirror that of conventional metaphyseal
enchondromas, their proximity to the joint space may lead to more frequent
painful symptoms, a propensity for physeal involvement, and the need for
earlier definitive surgical intervention.
Level of Evidence: Prognostic Level IV. See Instructions
to Authors for a complete description of levels of evidence.