Biopsy
What is a biopsy?
A biopsy is a procedure in which we take the sample from abnormal mass, which was examined by a pathologist to diagnose the disease.
In which disease we use biopsy for diagnosis?
In all those diseases where tissue diagnosis is needed for further management.
Types of biopsy relating to orthopedic oncology?
FNAC: In this procedure, sample taken from 22 – 20 gauze needle. Only cells were taken out and then slides were prepared for the examination. Accuracy is only 60%. There is no role of FNAC in primary Diagnosis in Orthopaedic Oncology. Because for diagnosis tissue architecture is needed but FNAC provides only cells. It has a role only to confirm the recurrence or involvement of lymph nodes.
Core needle Biopsy/Trucut Biopsy: in this procedure, we take tissue sample with a specially designed needle, in which the core of tissue was taken out and examined further for diagnosis. This procedure is done with a very small incision, less contamination of another compartment, can be done in local anesthesia. Have 90-95% accuracy.
Incisional Biopsy: In this procedure, we make an incision and take enough sample for pathological examination. Should always be done with precaution, so that minimal contamination of another compartment. Regional or general anesthesia needed. Have 99% accuracy.
Excisional Biopsy: in this procedure, we resect the whole tumor with intact capsule and send for pathological examination. Only smaller than 3 cm, and the superficial lesion should be examined by this technique. Excision should be done by following the oncological principle of resection.
Planning of biopsy
It is a very important step in diagnosis and management of sarcoma.
Need the following investigation in hand to plan.
1. Clinical history and examination
2. Full limb length x-rays
3. Full limb length contrast MRI
How sarcoma surgeon plans for a biopsy?
After getting history, examination, and radiology, surgeon have some differentials in his mind, and keeping future plan for management, guide him to do a proper biopsy.
Biopsy should always be done by treating sarcoma surgeon.
The harm of the wrong biopsy?
1. Contamination of another compartment possible
2. May lead to unnecessary amputation.
3. May lead to unnecessary additional procedures like Flap or tissue graft.
4. May lead to repeat biopsy.
How MRI helps, to guide biopsy?
MRI needs to be study meticulously, it shows area of necrosis and extension of lesion and position of neurovascular bundle in relation to lesion. Surgeon should not take biopsy from necrotic areas and should avoid to injury to nerve and vessels. Path of biopsy should be according to future surgical approach determined by treating Sarcoma Surgeon.
Is it possible, that we may need repeat biopsy even after done by sarcoma specialist?
Yes, sometimes there is chances of repeat biopsy even in hand of experts.
Is it possible that, in some cases we don’t need biopsy?
Yes, there are some ‘do not touch’ lesions, where biopsy should not be taken. In those cases, history, examination and radiology is sufficient for diagnosis, but with close follow-up.
Consequences of wrong Biopsy?
This needs to understand that, while resecting tumor, we need to resect biopsy scar along with tumor, en-bloc. For that biopsy scar should be present in the way of incision line of surgery. Sometime, non-sarcoma surgeon doesn’t know about this and they did biopsy, without planning and may lead to unnecessary difficult surgery, and sometimes amputation. Wrong Biopsy may lead to higher chances of recurrence.
