Diagnosis


During his National University tenure, Prof Suresh Nathan established and grew the Orthopaedic Oncology Unit, which handles bone and soft tissue tumors in all age groups from children to adults, into the largest of its kind in Singapore. He continues to contribute his expertise into the group with 50 years experience and 100 publications and has been credited with significant discoveries in musculoskeletal oncology – chief amongst them molecular basis of bone tumor growth and microsurgical joint transfers. 'Orthopaedic oncology' or 'musculoskeletal oncology' offers a very wide range of abilities from prosthetic to bone transplant type options because our specialists hold dual roles as either joint replacement or microsurgical surgeons. It is therefore a completely unique resource specialized in the care of this very demanding field in South East Asia.

Common Signs & Symptoms

  • Presenting history
    1. Age
    2. Pain
      1. Unrelenting
      2. Disturbs sleep
      3. Can be mechanical or organic (cf mechanical causes of pain which are usually only mechanical)
    3. Systemic upset
    4. LOA, LOW
    5. SOB
    6. Bladder, bowel disturbance
  • Family history
    1. Syndromes
    2. “General cancer load”
  • Past history
    1. Syndromes
    2. Cancer history
  • Physical examination
    1. General physical examination
    2. Springing sign
    3. Spine
    4. Masses
    5. Cutaneous stigmata
    6. Café-au-lait
    7. Capillary malformations
    8. Limb inequality

 

Common Causes by age

Age

Benign tumors

Malignant tumors

Tumor-like conditions

Birth to 5 years

Eosinophillic granuloma

Leukaemia

Osteomyelitis

 

 

Metastatic neuroblastoma

Non-accidental injury

5 to 15 years

Unicameral bone cyst

Ewing's sarcoma

Fibrous dysplasia

 

Osteochondroma

Osteosarcoma

Osteomyelitis

 

Aneurysmal bone cyst

 

Osteofibrous dysplasia

 

Osteoid osteoma

 

Stress fracture

 

Enchondroma

 

 

 

Non-ossifying fibroma

 

 

 

Chondromyxoid fibroma

 

 

 

Chondroblastoma

 

 

15 to 20 years

Unicameral bone cyst

Osteosarcoma

Fibrous dysplasia

 

Osteochondroma

Ewing's sarcoma

Stress fracture

 

Osteoid osteoma

 

 

 

Aneurysmal bone cyst

 

 

 

Nonossifying fibroma

 

 

 

Giant cell tumor

 

 

 

Enchondroma

 

 

 

Chondroblastoma

 

 

 

Chondromyxoid fibroma

 

 

20 to 50 years

Giant cell tumor

Chondrosarcoma

Fibrous dysplasia

 

Enchondroma

 

 

Above 50 years

Brown tumors

Metastasis

Degenerate cysts

 

 

Chondrosarcoma

Metabolic disease

 

 

Malignant fibrous histiocytoma

 

 

 

Parosteal osteosarcoma

 

Diagnosis 

  1. X-rays remain the most important diagnostic modalities for bone tumors. 
  2. MRI help confirm diagnoses and are necessary for local staging and planning surgery. 
  3. Bone scans are still the gold standard in determining local activity and bony spread. 
  4. CT chest is necessary to determine spread of the tumor to the lungs. 
  5. Biopsy may or may not be necessary in certain instances and is covered elsewhere. It gives the type of tumor, the grade (it's aggressiveness) and decides if chemotherapy or radiotherapy is needed. 

Figure 1. The diagnosis is often apparent on a simple xray in as high as 90% of cases. The other modalities are for staging and planning of surgery.

Following these various modalities the patient is given a stage to indicate how far it has spread: 



Figure 2. Staging incorporates the aggressiveness, size and extent of spread to give an idea of how advanced the disease is.

Others
  • CT of specific areas are useful in pelvic tumors or in places where there are many bones or with hardware (metal screws, implants). 
  • FDG PET use have become widespread but for the information they provide it does not appear to have changed the initial treatment of these conditions. 


Treatment Options
Primary cancers of the bone
Also known as bone sarcomas, osteosarcomas and chondrosarcomas are the two most common variants. These affect individuals of all ages but in particular people in the second and sixth decades of life. The challenges in managing these conditions revolve around removal of these tumors in a way that they do not recur and then reconstruct the structure to replace the missing anatomical structure and restore function.

The general approaches to reconstruction can be both biological and prosthetic. In biological solutions the draw is that one is able to reconstruct the missing structure with biological materials and host bone which have a virtually life-long durability. These methods, however, do result in donor site morbidity and have a relatively high early complication rate. The prosthetic approach where joints and segments are replaced by metal implants have high patient acceptability and good function but are subject to wear. We have a unique blend of both approaches and hence only the most appropriate is offered in specific cases. Our service has contributed pioneering work in this field with more than thirty years of research in developing novel solutions to the problem. We even have our own in-house bone bank which is the only one of its kind in Singapore and has been responsible for setting up centers regionally.

Primary cancers of the soft tissues
Also known as soft tissue sarcomas, liposarcomas and malignant fibrous histiocytomas more commonly occur in adulthood whereas rhabdomyosarcomas and synovial sarcomas occur in childhood.

The specific ability of the orthopaedic oncologists is in his ability to resect these tumors primarily to save life and yet secondarily reconstruct defects in a way that maintains function. In addition resections are done in a way that facilitate radiation therapy that is often used in these conditions.

Metastasis
When cancers in other parts of the body spread to the bone and soft tissues, these structures become compromised. As a result patients develop fractures that do not heal and they become invalid. This in turn reduces their life expectancy. Our specialists have been trained to reconstruct these afflicted bones and joints so that patients with such conditions are able to lead their remaining lives out with dignity. Furthermore, our staff specifically ensures the great sensitivity needed towards such patients.

Benign tumors of the bones and soft tissues
These conditions are commonly encountered and treated by general orthopedists and surgeons. Our special input in this field is in meeting two of the main challenges provided by these conditions. Firstly, these conditions provide diagnostic problems – that is they can be mistaken for more serious conditions like cancers. Our service works closely with the Departments of Pathology and Radiology with whom we meet regularly and such cases are amply discussed before embarking on surgery. This minimizes the risk of mis-diagnoses. Next, when such conditions compromise function and need to be operated on (eg. Weakening the bone to the point that they may break) we would be able to reconstruct these conditions with minimal functional embarrassment.

Other links on the site of interest: