Description
Clinical History
A 16-year old male presented with a 3-month history of increasingly swollen and painful right knee. On examination, there was a palpable tender swelling above the right knee. Blood test showed a raised Alkaline Phosphatase level. A knee x-ray showed periosteal reactive changes in the distal femur suspicious for a bone malignancy. The patient then underwent staging CT and MRI evaluation of the right leg. He underwent adjuvant chemotherapy prior to resection of his right femur. He made a full recovery.
Pathology
The specimen is the patient's excised distal femur. On the cut surface, there is a large pale infiltrating tumor, 10 cm in greatest diameter, extending through the periosteum near the articular surface. This is an osteosarcoma of the femur.
Further Information
Osteosarcomas are a malignant tumor of bones that are characterized by the production of osteoid matrix or immature bone. It is the most common primary malignancy of bone. Most occur in the distal femur with the tibia and humerus being the most frequent sites affected. Men are more commonly affected than women. They occur in a bimodal age distribution, with most occurring in children and adolescents under 20 years of age and the second peak occurring in older adults over 60.
Secondary osteosarcomas are more common in older patients. Secondary osteosarcomas occur in patient's bones with predisposing conditions such as Paget's disease, bone infarcts and previous irradiation. Mutations in tumor suppressors and oncogenes, such as RB, TP53 and INK4a have been shown in osteosarcomas.
Osteosarcomas usually present with painful, enlarging masses. Pathological fractures can also be the first presenting complaint. Constitutional symptoms are usually not present. Alkaline phosphatase and lactate dehydrogenase may be elevated on blood tests. X-rays can show features of bone destruction, a mass or signs of a periosteal reaction, such as a sunburst appearance or triangular shells of reactive bone (Codman's Triangle). MRI of the affected bone is used to evaluate local staging of the tumor while CT of the body is used to evaluate for distant spread. The tumor may be biopsied in some cases.
The lungs are the most common site for distant metastases followed by the bones and brain. Treatment involves neoadjuvant chemotherapy followed by surgery. 5-year survival rate for localized osteosarcoma is 60-70% but this drops to <20% in patients with distant metastases.
Advantages
- Anatomically accurate and identical to real specimen
- No ethical issues - not real human body parts
- Reasonably priced
- Available within a short lead time
- Reproducible, several identical prints can be used as a classroom set
- Can be produced in different sizes to cater for the needs of the teacher
Human Cadavers
- Access to cadavers can be problematic. Many countries cannot access cadavers for cultural and religious reasons
- Cadavers cost a lot money
- High cost for establishing your own plastination suite
- Wet specimens cannot be used in uncertified labs
- Dissection of cadavers is a lot of staff time and that is a cost
- Storage of cadaver material needs special refrigeration etc. which has coast
- If you want another specimen you have to start all over again
Plastinates
- Costs
- Ethical issues
- Timeframe for plastination process
- Many countries do not allow their importation
- One of a kind
Superior 3D print results compared with conventional methods
- Vibrant color offering with 10 million colors
- UV-curable inkjet printing
- High quality 3D printing that can create products that are delicate, extremely precise and incredibly realistic
Clear Support Material
- To avoid breakage of fragile, thin, and delicate arteries, veins or vessels, a clear support material is printed on such spots. This makes the models robust and can be handled by students easily.
