A Study of Giant Cell Lesions of Bone

Introduction: Giant cell lesions of bone include true giant cell tumors & numerous benign osteoclasts and pseudo-anaplastic-appearing giant cells containing variants. Many times it is difficult to differentiate between true giant cell tumor and other tumor like conditions. Aims: To study histopathology of various giant cell rich tumour and tumour like conditions of bone. Methods: Retrospective analysis of 50 cases of giant-cell rich lesions of bone diagnosed and treated at Smt. N.H.L. Municipal Medical College Ahmedabad, Gujarat during 1st January 2002 to 1st January 2003 included in the study. Patients’ clinical, radiological details, histopathological examination were studied using structured proforma. The cases were classified in different categories according to age groups, types of tumour, benign versus malignant category. Results: The most common giant cell containing benign tumor is giant cell tumor (19 cases) followed by Aneurysmal bone cyst (5), Most of the giant cell containing tumors of bone are found in younger age group and are located in epiphysis The common giant cell containing malignant tumor is osteogenic sarcoma (7 cases) followed by Talangiectatic O.S (01). The majority of cases found in age between 15 28 years and most common sites are epiphysis of long bones. Conclusion: The most common giant cell rich benign bone tumour is giant cell tumour and most common giant cell rich malignant bone tumour is osteosarcoma commonly occurs in younger age groups in the epiphysis region long bones.


Results
Most of the giant cell containing tumors of bone is found in younger age group in second and third decade while aneurysmal bone cyst is found in third and fourth decade. Most of the giant cell tumors are found between 15 to 40 years of age.
In present study, giant cell tumor of bone is located in epiphysis in most of the cases. Aneurysmal bone cyst is located in the epiphysis as well as metaphysis of long bones. Telangiectatic osteosarcoma is located near shaft of long bones. Langerhan's cell histiocytosis is located in the skull. Chondromyxoid fibroma has been detected in small bones of hands and foot.
The osteoclastoma is maximum of all benign lesions.
Statistical analysis: T test between age and type of lesion has been applied The mean for benign giant cell leson is 24.21 and for malignant tumor the mean is 19.50. There is no statistical significant difference seen between the ages and the nature of lesion (Table-1) The giant cell tumor of bone and other giant cell rich lesions of bone are is more common in male. (Table -2 & Table 3) The giant cell rich lesion are most common in tibia 17(34.0) followed by femur 14(28.0) Fishers exact test= 5.821, p value= 1.00 (Table-4) According to present study, the most common giant cell rich lesion is true giant cell tumor (19) followed by osteosarcoma (07) ( Table-5  There is no statistical significant difference seen between the ages and the nature of lesion

Discussion
The diagnosis of giant cell-rich lesions of bone is often problematic even for the experienced pathologist. The diagnostic key lies in multinucleated osteoclast-like giant cells and a mononuclear stroma. [7] From the histological picture alone it is often difficult to distinguish between individual entities such as conventional giant-cell tumor of bone, non-ossifying fibroma, giant-cell tumor in hyperparathyroidism or an aneurysmal bone cyst. [8] Total 50 bone lesions were studied and divided into benign and malignant tumors. The incidence of true giant cell tumor (osteoclastoma) is maximum of all lesions in present study which is higher than Goldenberg and Dahlin et al. [9] Although giant cell tumor is considered as potentially malignant tumor, it is considered in benign because all giant cell tumors in this study show no atypical features in stroma. [10] Most of the giant cell containing tumors of bone are found in younger age group in second and third decade between 15 to 40 years of age while aneurysmal bone cyst is found in third and fourth decade. [11] In present study, giant cell tumor of bone is located in epiphysis in most of the cases. Giant cell tumors have higher incidence in male population in present study. Aneurysmal bone cyst is more common in males in the present study. Aneurysmal bone cyst is located in the epiphysis as well as metaphysis of long bones. According to Modi et al [12] osteoclast like giant cells may dominate the histologic pattern not only in the giant cell tumor but also a variety of bone lesions namely aneurysmal bone cyst, giant cell-rich osteosarcoma, chondroblastoma, giant cell reparative granuloma and fibrous dysplasia. According to Kumavat et al [13] out of 216 cases of bone tumors Out of 216 cases, primary bone tumors were 151 (69.91%), metastatic tumors were 40 cases (18.52%) and tumor like conditions were 25 cases (11.58%). According to Sunita A.Bamanikar et. Al [14] .The most common benign tumour is osteochondroma followed by giant cell tumour of all benign tumours. osteosarcoma is commonest malignant tumour.

Conclusion
Detailed histopathological study and clinico-radiological correlation is very helpful to arrive at precise and accurate diagnosis in giant cell rich lesions. The common giant cell rich bone lesion are true giant cell tumor