pathology

Question 1

Treatment of bone tumours

Answer 1

surgery to remove the tumour and surrounding tissue to reduce the risk of recurrence.

Typically a bone tumour is removed with a wide margin of 3‐4cm of bone and a cuff of normal muscle all around. The biopsy tract is also removed with the tumour. The joint involved needs reconstruction with special joint replacements which are typically much bigger than standard replacements to counteract the extensive bone loss.

Adjuvant chemotherapy and radiotherapy are used if appropriate and neo‐adjuvant chemotherapy (given prior the surgery) can improve survival. Advances in adjuvant therapy have improved the survival rates from primary bone tumours from around 50% to 80% 5 year survival over the last few decades.

Question 2

bone tumour investigations

Answer 2

Staging investigations usually include bone scan and CT chest. MRI and CT are useful to determine the local extent of the tumour and the involvement of muscle, nerves and vessels. Biopsy is required for histological diagnosis and grading prior to definitive surgery. In general the biopsy should normally be performed in the specialist centre where definitive surgery is performed.

f there are multiple metastases or the lesion is suspected to be metastatic, the primary tumour should be sought (there may be history of previously diagnosed or treated primary). Examination may include breast exam or PR exam. CXR may detect a pulmonary lesion. Blood tests include serum calcium (for hypercalcaemia), LFTs (to look for liver mets), plasma protein electrophoresis (for myeloma), full blood count and U&E.

Question 3

lytic vs blastic metastases

Answer 3

lytic lesions, which destroy bone material; and blastic lesions, which fill the bone with extra cells.

Question 4

where are bone metastases likely to come from?

Answer 4

breast  carcinoma 
prostate carcinoma 
lung carcinoma 
renal cell carcinoma 
thyroid adenocarcinoma

Question 5

which bones are most frequently involved with metastases?

Answer 5

vertebra, pelvis, ribs, skull, humerus and long bones of the lower limb.

Question 6

what may cause diffuse soft tissue swellings vs local soft tissue swellings?

Answer 6

Soft tissue swellings may be diffuse (as in synovitis or oedema) or local. Local swellings include inflammatory swellings (bursitis, rheumatoid nosules), infection (abscess), cystic lesions (ganglion, meniscal cyst, Baker’s cyst), benign neoplasms and malignant neoplasms