Benign giant cell tumor

Giant cell tumor of bone and secondary osteoarthritis

Giant cell tumor of bone is a commonly encountered aggressive epiphyseal bone tumor, most often treated surgically. The natural history and presentation are classically described but the histopathology is poorly understood. Intralesional curettage is the mainstay of treatment, but there is significant variation in the use of adjuvant and cavity filling modalities. No gold standard has been agreed upon for treatment, and a variety of techniques are currently in use. Given its location, secondary osteoarthritis is a known long-term complication. This review examines the natural history of giant cell tumors, treatment options and complications, and subsequent development of osteoarthritis. Arthroplasty is usually indicated for secondary osteoarthritis although data is limited on its efficacy. Further directions will likely center on improved pharmacological treatments as well as improved arthroplasty techniques.

Bone and Soft Tissue Tumors About the Foot and Ankle

The foot and ankle delicately balance the need for support of the weight of the human body, with the need for flexibility. Palpable masses about the foot and ankle, therefore, are most commonly related to trauma or mechanical instability. Non-neoplastic causes, such as ganglion cysts and callus, therefore, predominate. However, the radiologist must be aware of the imaging appearance of less common benign and malignant neoplasms that can involve the foot and ankle.

Genetic Analysis of Giant Cell Lesions of the Maxillofacial and Axial/Appendicular Skeletons

PURPOSE

To compare the genetic and protein expression of giant cell lesions (GCLs) of the maxillofacial (MF) and axial/appendicular (AA) skeletons. We hypothesized that when grouped according to biologic behavior and not simply by location, MF and AA GCLs would exhibit common genetic characteristics.

MATERIALS AND METHODS

This was a prospective and retrospective study of patients with GCLs treated at Massachusetts General Hospital from 1993 to 2008. In a preliminary prospective study, fresh tissue from 6 aggressive tumors each from the MF and AA skeletons (n = 12 tumors) was obtained. RNA was extracted and amplified from giant cells (GCs) and stromal cells first separated by laser capture microdissection. Genes highly expressed by GCs and stroma at both locations were determined using an Affymetrix GeneChip analysis. As confirmation, a tissue microarray (TMA) was created retrospectively from representative tissue of preserved pathologic specimens to assess the protein expression of the commonly expressed genes found in the prospective study. Quantification of immunohistochemical staining of MF and AA lesions was performed using Aperio image analysis to determine whether immunoreactivity was predictive of aggressive or nonaggressive behavior.

RESULTS

Five highly ranked genes were found commonly in GCs and stroma at each location: matrix metalloproteinase-9 (MMP-9), cathepsin K (CTSK), T-cell immune regulator-1 (TCIRG1), C-type lectin domain family-11, and zinc finger protein-836. MF (n = 40; 32 aggressive) and AA (n = 48; 28 aggressive) paraffin-embedded tumors were included in the TMA. The proteins CTSK, MMP-9, and TCIRG1 were confirmed to have abundant expression within both MF and AA lesions. Only the staining levels for TCIRG1 within the GCs predicted the clinical behavior of the MF lesions.

CONCLUSIONS

MMP-9, CTSK, and TCIRG1 are commonly expressed by GCLs of the MF and AA skeletons. This supports the hypothesis that these lesions are similar but at different locations. TCIRG1 has not been previously associated with GCLs and could be a potential target for molecular diagnosis and/or therapy.

Regional variation and challenges in estimating the incidence of giant cell tumor of bone

BACKGROUND

Estimating the incidence of giant cell tumor of bone is challenging because few population-based cancer registries record benign bone tumors. We compared two approaches, the indirect (relative index) estimation approach used in The Burden of Musculoskeletal Diseases in the United States (BMUS) and a direct incidence rate approach (from registries that record giant cell tumor), to estimate giant cell tumor incidence in France, Germany, Italy, Spain, the U.K., Sweden, Australia, Canada, Japan, and the U.S.

METHODS

Giant cell tumor of bone incidence was calculated with use of the BMUS relative index of giant cell tumor to osteosarcoma in three scenarios (low, base case, and high) from case series. We compared the BMUS approach with the latest data from tumor registries in Australia (1972 to 1996), Japan (2006 to 2008), and Sweden (1993 to 2011) that record giant cell tumors. United Nations population estimates were used to project results to 2013.

RESULTS

The low scenario in the BMUS approach reflects data from Unni and Inwards; the incidence of giant cell tumor of bone is 0.34 relative to osteosarcoma. As the incidence of osteosarcoma is 31.4% of the total incidence of bone and joint cancers, the incidence of giant cell tumor is 0.11 times that of all bone and joint cancers. The base scenario reflects the series by Mirra et al., with a giant cell tumor incidence of 0.47 relative to osteosarcoma (0.15 to all bone and joint cancers). The high scenario reflects the series by Ward, with an incidence of 0.84 relative to osteosarcoma (0.26 to all bone and joint cancers). Differences among the three series reflect referral to a national center of excellence compared with referral to a local oncology practice. Registry data indicated a giant cell tumor incidence rate per million per year of 1.33 in Australia, 1.03 in Japan, and 1.11 in Sweden in 2013. The estimated incidence rate per million in the ten countries in 2013 ranged from 1.03 (Japan) to 1.17 (Canada) with use of the registry-based approach and from 0.73 (Japan) for the low scenario) to 2.20 (Germany) for the base case with use of the BMUS approach.

CONCLUSIONS

Giant cell tumor of bone affects approximately one person per million per year in the ten countries studied. Estimates derived with use of age-specific incidences from tumor registries were typically within the range of the low and base case BMUS scenarios. We recommend the registry-derived method for estimating the incidence of giant cell tumor.

Recombinant human bone morphogenetic protein type 2 jaw reconstruction in patients affected by giant cell tumor

Giant cell tumor (GCT) is a relatively common skeletal tumor. Mandibular localization of this tumor is usually treated with resection of the tumor area. Several autogenous bone-grafting techniques are available for the restoration of large continuity defects of the mandible. However, these procedures are associated with limitations involving postoperative morbidity, difficulty in ambulation (hip graft), and pain. The development of a technique of surgical reconstruction not involving autogenous bone would offer new opportunities for facial bone reconstruction, particularly of the mandible. This study aims to underline the effect of recombinant human bone morphogenetic protein type 2 (rhBMP-2) in a collagen carrier with concomitant bone grafting material in the restoration of continuity critical-size defects after GCT resection in the mandible. The rhBMP-2 was used with absorbable collagen sponge. A total dose of 4 to 8 mg of rhBMP-2 was delivered to the surgical site in concentrations of 1.5 mg/mL. The patient was followed up over a period from 6 to 18 months. Occlusal function was initially restored with conventional prosthesis. Bone formation in the surgical area could be palpated at the end of 3 to 4 months and identified radiographically at the end of 5 to 6 months. The results clearly indicated that the use of rhBMP-2 without concomitant bone grafting materials in large critical-size mandibular defects secondary to GCT produced excellent regeneration of the area, establishing the basis for the return of prosthodontic function.

Radiation therapy for giant cell tumors of bone

For giant cell tumors of bone, does radiotherapy provide a safe and effective treatment? This retrospective review includes 24 patients with 26 histologically diagnosed tumors treated with megavoltage radiotherapy between March 1972 and July 1996. Of the 10 recurrent tumors, five had an intralesional resection, two had a biopsy, and three had no biopsy before radiotherapy. Of the 16 previously untreated tumors, one was irradiated after a marginal resection, five after an intracapsular resection, and 10 after biopsy alone. The total doses ranged from 35 to 55 Gy (median, 43 Gy) in fractions of 1.67 to 2.33 Gy per day. Twenty of 26 tumors (77%) were controlled locally. All of the local recurrences occurred within the irradiated field. Five of six patients with local recurrence were treated successfully with additional surgery. Salvage surgery after local recurrence required amputation of an extremity in three patients and a total knee replacement in one patient. The ultimate local control rate was 96% with one patient alive with progressive disease. Lung metastases in one patient were treated successfully with surgery, chemotherapy, and radiotherapy. In one patient a radiation-induced sarcoma developed 22 years after treatment. The authors conclude that radiation therapy is a safe and effective treatment option for benign giant cell tumors of bone. A total dose greater than 40 Gy is the only variable found to significantly influence local control.

From the archives of AFIP. Imaging of giant cell tumor and giant cell reparative granuloma of bone: radiologic-pathologic correlation

The radiologic features of giant cell tumor (GCT) and giant cell reparative granuloma (GCRG) of bone often strongly suggest the diagnosis and reflect their pathologic appearance. At radiography, GCT often demonstrates a metaepiphyseal location with extension to subchondral bone. GCRG has a similar appearance but most commonly affects the mandible, maxilla, hands, or feet. Computed tomography and magnetic resonance (MR) imaging are helpful in staging lesions, particularly in delineating soft-tissue extension. Cystic (secondary aneurysmal bone cyst) components are reported in 14% of GCTs. However, biopsy must be directed at the solid regions, which harbor diagnostic tissue. These solid components demonstrate low to intermediate signal intensity at T2-weighted MR imaging, a feature that can be helpful in diagnosis. Multiple GCTs, although rare, do occur and may be associated with Paget disease. Malignant GCT accounts for 5%-10% of all GCTs and is usually secondary to previous irradiation of benign GCT. Treatment of GCT usually consists of surgical resection. Recurrence is seen in 2%-25% of cases, and imaging is vital for early detection. Recognition of the spectrum of radiologic appearances of GCT and GCRG is important in allowing prospective diagnosis, guiding therapy, and facilitating early detection of recurrence.