PMC

A female patient with late recurrent osteosarcoma 5 years post-surgery. (A) X-ray imaging showing osteoblastic destruction of the distal left tibia. (B) X-ray showing nonunion between the host bone and the distal side of the inactivated bone, accompanied by a posterior protrusion and varus deformity at 29 months post-surgery. (C) At 62 months subsequent to the initial surgery, the patient was hospitalized due to one month of ankle pain associated with a mass. (D) Post-operative pathological diagnosis demonstrating a fibroblastic osteosarcoma, identical to that diagnosed in the initial pre-operative examination (HE; magnification, ×10). HE, hematoxylin and eosin.

A male patient with late recurrent osteosarcoma 10 years post-surgery. (A) X-ray imaging showing osteoblastic destruction of the left distal femur, partial osteolytic changes, a visible periosteal reaction and a soft tissue mass. (B) MRI showing a mixed high and low signal intensity in the left distal femur, which formed a large soft tissue mass. (C) X-ray showing the allografting bone resorption and femoral condyle fragmentation at 8 years post-surgery. (D) X-ray imaging revealing a tumor shadow between the prosthesis and the host bone in the middle of the right femur with a soft tissue mass at 9 months after the second surgery. The lesion was confirmed to be an osteosarcoma by a post-operative pathological examination.

A female patient (case 1) with late recurrent osteosarcoma at 6.5 years post-surgery. (A) Radiography revealing a mixed osteolytic-osteoblastic lesion with periosteal reaction of the right distal femur and a shadow of a soft tissue mass. (B) Histological examination of the biopsy specimen demonstrating the diagnosis of osteosarcoma (HE; magnification, ×10). (C) X-ray showing good healing between the inactivated and host bones at 6 months following an en bloc resection of the tumor and an inactivated bone replantation with preservation of the epiphysis. (D) X-ray showing the healing between the inactivated bone and femoral shaft at 6.5 years post-surgery. The diameter of the affected femur was thinner than that of the contralateral one and a forward protrusion between the inactivated bone and the preserving epiphysis was present. (E) During the second surgery, granulation-like tissue was identified in the medial femoral condyle. (F) A post-operative pathological examination of the specimens indicated that the curetted tissue was that of an osteosarcoma (HE; magnification, ×20). (G) PET/CT examination showing abnormal bone metabolism at the right distal femoral condyle. HE, hematoxylin and eosin; PET/CT, positron emission tomography/computed tomography.