Explore Real Clinical Cases

Explore real cases with stories and pictures

Explore Our On-Line Learning Content

Enhance your knowledge of tumors and their management

knee, thigh, distal femur, proximal tibia

32 year old man with pain in the knee

Case Identification
Case ID Number: 
20090709pk
Periosteal Reaction: 
absent
Benign/Malignant: 
unknown
Clinical case information
Case presentation: 

A 32 year old man presented with pain in the lateral aspect of his knee for six weeks. He had no history of injury and was otherwise healthy. Radiographs and bone scan are shown at right.

Laboratory results:: 
Labs were normal.
Differential Diagnosis: 
The differential should include active bone tumors that are likely to occur around the knee of an adult. The possibilities include aneurysmal bone cyst, eosinophilic granuloma, giant cell tumor, lymphoma, and infection. Tumors and lesions that might occur in this setting but are less likely include hyperparathyroidism, osteosarcoma, Ewing's sarcoma, myeloma, lymphoma, angiosarcoma, adamantinoma, and fibrous dysplasia.

50 year old tennis player with pain in the knee .

Case Identification
Case ID Number: 
20091117AD
Benign/Malignant: 
unknown
Clinical case information
Case presentation: 

The patient is a very pleasant woman who is an active tennis player and 50 years of age. She has had aching pain in the left knee and a radiograph revealed a bone lesion in the proximal tibia. The patient is seen at the request of her orthopedic surgeon.

Radiological findings:: 
The patient is generally healthy. She is currently taking no medicines. There is no family history of bone lesions or bone tumors. On detailed examination, the patient is in no acute distress, and is oriented to time, place, and person. Examination of the right knee shows normal appearance. There is no effusion. There is no erythema or swelling, no ecchymosis or bruising noted. The alignment of the knee is normal. The range of motion is full. In the proximal tibia there is no mass palpable. There is no tenderness over the proximal bone. There is no erythema or sign of inflammation. There is no popliteal adenopathy, no inguinal adenopathy, and no cervical adenopathy. The skin is normal and there is no cafe au lait spots.

51 year old with knee pain

Case Identification
Case ID Number: 
20090721KP
Periosteal Reaction: 
absent
Benign/Malignant: 
unknown
Clinical case information
Case presentation: 

A 51 year old woman presents with left knee pain for 1 year. There has been no previous history of disease, injury, or exposure.

Radiological findings:: 
A lytic lesion is seen in the distal femur. Plain xrays, bone scan, and MRI are performed. Images are shown at left.
Laboratory results:: 
None of significance.
Pathology results:: 
Biopsy results are shown.
Special Features of this Case:: 
This large tumor presents a significant risk of pathological fracture. How should this be addressed?
Image Reference: 

A 14 year old boy with pain and mass above the knee

Case Identification
Case ID Number: 
20091117AC
Benign/Malignant: 
unknown
Clinical case information
Case presentation: 

A 14 year old boy presents with pain and a mass above the knee.

Radiological findings:: 
Take a look at the AP and lateral radiographs first. Notice the extensive periosteal reaction. This pattern has been described as a "sunburst" appearance. Next take a look at at AP and lateral radiographs of the whole distal femur. What this case demonstrates is the relative "balance" or proportion between the volume of intraosseous abnormality and the volume of extraosseous abnormality. What I hope you can see is there seems to be about the same amount of tumor inside as outside the bone.
Differential Diagnosis: 
Osteosarcoma vs Ewing sarcoma
Treatment Options:: 
This patient is currently undergoing preoperative evaluation and will receive neoadjuvant chemotherapy. Ultimately he will need surgical treatment of one sort or another.The ultimate decision about what to do for this extremely challenging surgical problem will depend on the clinicopathologic stage of the tumor, the patient's response to treatment, and discussions with the patient and family.
Special Features of this Case:: 
This case is an osteosarcoma. The point here is to demonstrate the radiographic appearance of the tumor and to hint at the characteristic balance between the amount of tumor inside and outside the bone that may be seen in osteosarcoma. Why do we care? Because these features might help distinguish this tumor from the other tumor that is likely in this patient and this location, Ewing's sarcoma. As it happens, Ewing's sarcoma usually does not have this type of periosteal reaction. Ewing's may also have a much more "lopsided" appearance. There may be a small intraosseous tumor and a large soft tissue mass. In fact, the abnormality within the bone may be minimally visible in Ewing's tumor even while the mass outside the bone is very large. Bone tumors do not follow the "rules" and they do not always look they way they "should". Nevertheless, this case might help you decide between an osteosarcoma and a Ewing's tumor someday.
Syndicate content