Unusual Presentations of a Benign Cartilaginous Tumour- An Interesting and Extremely Rare Case Report

Chondroblastoma is one of the benign cartilaginous bone tumours. Location wise, it is mostly located in immature epiphysis of long bones. Along with epiphysis, many times it also involves metaphysis. Pure metaphyseal tumours are uncommon. Pure diaphyseal tumours are rarest with only very few cases reported in the literature. The most common age group for this tumour is 10-17 years. It is uncommon in patients less than 10 years and those more than 25 years of age. Diaphyseal chondroblastoma in less than 10 years of age group is extremely rare. Hereby, authors report a case of 14-month-old male child who presented to the paediatric orthopaedic outdoor with complaints of the swollen left leg and associated pain by the parents for the last 1 month. There was no history of trauma/weight loss/fever. No difficulty in walking was present. Local examinations of the left leg showed a well-defined globular swelling of size 3×3 cm in the middle part medial aspect. The underlying tibia was continuous with that of swelling having restricted painful movement. X-ray showed an osteolytic, expansile, cortical, eccentric lesion in the middle third (diaphysis) of the left tibia. Correlating the clinical and radiological findings, clinical diagnosis of osteofibrous dysplasia was considered. The intralesional curettage and bone grafting were done and tissue was sent for histopathology. Histopathology showed the characteristic findings of chondroblastoma. The final diagnosis of diaphyseal chondroblastoma of the left tibia was made. The postoperative events were unremarkable and the patient followed-up to eight months with a happy outcome without any residual disease or recurrence.