Lytic Lesion in the Femoral Epiphysis of a Young Patient with Anorexia: A Case Report

Epiphyseal tumours in young patients are a diagnostic challenge, largely due to their rarity. The differential diagnosis for a lytic lesion with well-defined margins at the epiphysis of a long bone in a young patient should fundamentally include three lesions typically found at the epiphysis: chondroblastoma, giant-cell tumour of bone and clear cell chondrosarcoma. Other conditions to consider include osteomyelitis, eosinophilic granuloma and osteochondral lesions of traumatic origin. Chondroblastoma accounts for less than 1% of total primary bone tumours and it is the third most common tumour within the cartilaginous lineage with benign histology, after enchondroma and osteochondroma, both of which have a much greater incidence, and the only tumour of lesser incidence is the chondromyxoid fibroma. Typically, it is found at the epiphysis of long bones in the lower limbs, especially the proximal humerus, the distal femur and the proximal tibia. In the case series published, 72% of the lesions are located in the lower limbs and 30% around the knee. At the proximal end of the femur, it is found at the femoral epiphysis or at the greater trochanter in a third of cases. In a few cases, as is also true with the giant-cell tumour of bone, the development of pulmonary metastases has been described. These lung lesions are histologically benign and, as such, can be considered pulmonary disease deposits whose development is promoted by surgery on the primary tumour or recurrent lesions [1,2]. The following case report is of interest due to the presentation with the symptom of anorexia, which is suggestive of malignancy and is to be interpreted with caution.