A 35-year-old man has experienced pain in the area of the left knee for more than 1 month. On physical examination, there is tenderness to palpation of the distal left thigh and knee. The area is firm, but there is no erythema or warmth. A radiograph of the left leg shows a 7-cm mass in the distal femoral epiphyseal area, with a “soap bubble” appearance. Microscopic examination of a biopsy specimen of the lesion shows multinucleated cells in a stroma predominantly composed of spindle-shaped mononuclear cells. What is the most likely diagnosis?
Osteitis fibrosa cystica
Answer:D Giant-cell tumor
The condition described in above question is giant cell tumour.Most cases of giant-cell tumor arise in the epiphyses of long bones of individuals 20 to 40 years old; there is a slight female predominance. The tumors may recur after curettage.
Although most are histologically and biologically benign, in rare cases, a sarcoma can arise in a giant-cell tumor of bone.
Ewing sarcoma is seen in the diaphyseal region and usually manifests within the first 2 decades of life. An osteoblastoma usually involves the spine.
Osteitis fibrosa cystica is a complication of hyperparathyroidism.