A 25-yr-old otherwise healthy woman presented with a 2-mo history of left anterior hip pain. The patient denied that a specific event was associated with the onset of her symptoms and described her symptoms as a sharp, deep, anterior-lateral pain that exacerbated with activity. The patient denied taking analgesics or receiving physical therapy. Her surgical history was unremarkable.
On examination, the patient had pain with palpation within the femoral triangle, medial to the iliopsoas, with intact, symmetric lower-extremity strength. Lower-extremity reflexes were 2+ and symmetric. Sensation was intact to light touch and pinprick. Resisted abduction and external rotation at the hip reproduced the patient's characteristic pain.
An iliopsoas bursitis or tendonitis was suspected. However, the patient did not respond to physical therapy, icing, and scheduled ibuprofen. On follow-up, the patient reported subjective instability with intermittent mechanical symptoms of the left hip. Further examination demonstrated increased, asymmetric internal rotation of the left lower extremity at the hip compared with the right. Diagnostic considerations included acetabular dysplasia or labral injury, and imaging was obtained.
Radiographs of the pelvis (Fig. 1) demonstrated no evidence of acetabular dysplasia, with a questionable “figure-of-eight sign” that can be seen with acetabular retroversion. A magnetic resonance arthrogram of the left hip demonstrated a superior and anterior labral tear with degenerative changes of the posterior labrum. Of note, a well-defined mass, 5.4 cm × 3.6 cm, in anteroposterior and transverse dimensions within the left acetabulum was identified (Fig. 2). The radiologic impression was a giant cell tumor or chondroblastoma, with malignancy being less likely. A computed tomography-guided biopsy of the acetabular mass confirmed the diagnosis of a giant cell tumor.
Giant cell tumor is a common benign bony tumor. It is most commonly diagnosed in the third decade of life, with an increased incidence in women.1 Giant cell tumors are commonly located at the metaepiphyseal regions of the long bones, with 50% of cases involving the distal femur or proximal tibia.2 Tumors involving the femoral head or the acetabulum are rare.2 Although giant cell tumors are considered benign, up to 3% of patients will have pulmonary metastasis.3 Treatments include localized curettage, using bone cement to refill the lesion space, or wide-area resection. One study identified a 16.6% recurrence rate of giant cell tumor after curettage3 and lower recurrence rates with wide-area resection.4 Bisphosphonates are also used as adjuvant therapy.
1. Dahlin DC, Cupps RE, Johnson EW: Giant-cell tumor: A study of 195 cases. Cancer
2. Werner M: Giant cell tumour of bone: Morphological, biological, and histogenetical aspects. Inter Orthop
3. Balke M, Schremper L, Gebert C, et al: Giant cell tumor of bone: Treatment and outcome of 214 cases. J Cancer Res Clin Oncol
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4. Liu HS, Wang JW: Treatment of giant cell tumor of bone: A comparison of local curettage and wide resection. Changgeng Yi Xue Za Zhi