International Journal of Basic and Applied Medical Sciences ISSN: 2277-2103 (Online) An Online International Journal Available at http://www.cibtech.org/jms.htm 2013 Vol. 3 (1) January-April, pp.220-224/Mondal et al. Case Report 220 GIANT CELL TUMOR OF LOWER END OF FEMUR IN A SKELETALLY IMMATURE-A RARE CASE *Surojit Mondal 1 , Aniket Chowdhury 2 and Goutam Bandyopadhyay 3 1 Department of Orthopaedics, B.S.Medical College, Bankura, West Bengal, India 2 Department of Community Medicine, B.S.Medical College, Bankura, West Bengal, India 3 Department of Pathology, R.G.Kar Medical College, Kolkata, West Bengal, India *Author for Correspondence ABSTRACT Giant cell tumor (GCT) is a benign locally aggressive tumor with a tendency for local recurrence. GCT of lower end of femur in a skeletally immature patient is of rare occurrence with very few cases reported so far. GCT in this location in skeletally immature patient is rare and should be considered in the differential diagnosis of a destructive bony lesion in both skeletally immature and mature patients. We report the rare case of GCT of lower end of right femur in a 10-year-old female and discuss the difficult aspects of diagnosis. Key Words: Giant Cell Tumor, Destructive Bony Lesion, Skeletally Immature INTRODUCTION Giant cell tumor (GCT) is a benign tumor which, however, is locally aggressive and has a tendency for local recurrence. It usually occurs in young adult of 20-40 years in the epiphyseometaphyseal region, with a male preponderance. Nearly 85%-90% is found in long bones, of which 50% occurs around the knee joint (Schajowicz et al., 1995).benign malignant tumour area frequently seen in third decade of life and pain is often felt over the lesion, (Hsu et al., 2007)usual sites are distal radius proximal humerus and fibula.unni2has reported an incidence of 2% in the hand and 1.5% in foot.GCT of the hand and foot seems to represent a different lesion than conventional GCT in rest of the skeleton (Mohan et al., 1980). It has higher incidence of multicentricity, appears in younger age, and has a shorter duration of symptoms, averaging 6 months or less before a diagnosis is made. Radio graphically an expanding eccentric zone of lucency is seen in long bones, extending into articular cartilage, producing a geographic lytic lesion. Sclerosis is unusal, and periosteal new bone formation is rarely seen. Some giant cell tumours produce a large area of destruction. Metaphyseal location has been reported in rare cases, mostly in children .Radiographic feature of GCT other than long bones are nonspecific and are not like other osteolytic lesion The diagnosis of GCT is frequently delayed as symptoms may primarily be attributed to vague clinical symptoms. MRI provides a more sensitive tool for evaluation of the nature and extent of tumour and may help in differentiating GCT from other tumour. Furthermore, histological examination is necessary for diagnosis, as clinical presentation and radiological image are not conclusive. Histological finding consist of giant cells scattered uniformly throughout the lesion. They may contain 40-60 nuclei and show irregular border. Areas of infract like necrosis are common and there may be spindle cell reaction around the zone. The spindles cell may have storiform pattern .sometime only few foci with giant cell will be present. The nuclei of proliferating tumour cells are round to oval or spindle shaped. Mitoses are seen frequently in this lesion (Hsu et al., 2007). We present cases of a GCT of lower end of RT femur in a 10 years old girl and discussed the difficult aspect of diagnosing GCT in this unusual age group CASES A 10year-old female presented with swelling over the front of the rt knee for12 months and pain for 5 months. The swelling was insidious in onset and had progressively increased in size. The pain was mild to