Principles of biopsy 

Principles of biopsy 11‌‌

Needle biopsy of bone 11‌

Open biopsy of bone 14‌

Excision of benign bone tumour 16

Bone cyst curettage with or without bone graft 17

Malignant tumour principles 20

Viva questions 22

 

Sarcomas can broadly be classified into benign or malignant tumours and can be either of soft tissues or of bone. All tumours should be managed via a multidisciplinary team (MDT) approach at an appropriate dedicated tumour unit consisting of specialised oncology surgeons, radiologists, histopathologists, paediatricians and oncologists. Appropriate early referral to a sarcoma unit with careful diagnosis and coordinated management play a fundamental role in achieving the most successful outcome. Careful discussion and planning from time of initial presentation through to postoperative care and surveillance are critical.

 

Principles of biopsy‌

All patients presenting with a suspected sarcoma or isolated metastasis should be referred and discussed at a sarcoma MDT. Once appropriate staging investigations have been performed, a tissue diagnosis is required to gain a histological diagnosis and plan subsequent treatment. The biopsy is planned as part of the MDT between the oncology surgeon and the interventional radiologist.

 

1. Performed at a specialised sarcoma centre with appropriate histopathology support

2. Planned in accordance with the operating oncology surgeon

3. Includes representative tissue – often from the periphery of the lesion or a membrane as the central part is often necrotic and non-diagnostic

4. Should not violate any surrounding compartments

5. Biopsy tract should be marked by tattoo to aid excision at time of definitive surgery

Needle biopsy of bone‌

Preoperative planning

Indications

To obtain a histological diagnosis so that further treatment can be planned.

 

Contraindications

Lesions that are closely related to neurovascular structures, where a needle biopsy would put these structures at risk.

Patients should also be warned that a second needle biopsy or open biopsy may be necessary if an inadequate tissue specimen for histological diagnosis is obtained.

 

 

Consent and risks

• Neurovascular injury and infection are the main risks

• Possible tumour seeding

 

 

Templating

The needle entry point and tract need careful thought and should be planned by the surgeon performing the tumour resection, as the biopsy tract will need to be excised if malignancy is found.

Fine needle aspiration (FNA) is not used in sarcoma diagnosis and is largely reserved to diagnosing carcinoma. A thicker-bore needle (11G or 13G), capable of boring through the outside of the lesion and taking core biopsies such as a Jamshidi needle (Figure 2.1), is preferable.

For tumours that have a large soft tissue component or that have destroyed the cortex, a Tru-Cut or Temno (preloaded) needle can be used. These take a slice of tissue and come in 11 and 14 gauges. If there is doubt that the tissue obtained at biopsy may not be representative, a smear and/or frozen section can be performed by the histopathologist which may also provide a provisional diagnosis.

 

Anaesthesia and positioning

Needle biopsy can be done under local, local with sedation or general anaesthesia. For children, hard lesions and lesions that may be difficult to access, a general anaesthetic should be used.

Positioning is dependent on the area to be reached and if necessary the imaging modality being used.

 

Surgical technique

Landmarks and incision

The line of the biopsy should be sited in the line of a possible future surgical incision, so that it can be excised at the time of surgery (Figure 2.2). It must pass directly to the site of the tumour

 

 

 

 

Figure 2.1 Jamshidi needle.

 

and through only the myofascial compartment in which the tumour is located, preferably through muscle and away from the neurovascular structures at risk. It should aim to take a representative sample of the tumour, which can be identified on pre-biopsy imaging. The needle is passed after a simple stab incision in the skin with a number 15 blade.

 

Deep dissection

The needle is passed through the stab incision directly into the area being biopsied, under radiological control.

 

Technical aspects of procedure

Multiple core biopsies are needed, aiming to minimise diversion from the tract. In cases where preoperative imaging is atypical or where infection is suspected, samples should also be sent for microbiology.

The needle should not be passed through the lesion into normal tissue. For lesions close to joints, the needle must not pass through the capsule and therefore potentially contaminate the joint. It may be necessary to drill the bone prior to needle insertion in sclerotic lesions. Careful handling of the specimens is important so as not to destroy the microarchitecture. Discussion with the histopathologist will elucidate whether they wish to receive the specimen fresh or fixed in formalin.

 

Biopsy

Deltopectoral approach

 

 

 

Figure 2.2 Position of biopsy for proximal humeral tumour – in the line of the deltopectoral approach, but slightly lateral so that the needle passes through the deltoid muscle and avoids the cephalic vein.

 

Closure

Use Steri-Strips.

 

Postoperative instructions

• Neurovascular and routine observations.

• Local pressure in the case of vascular lesions.

  Recommended references

  Saifuddin A, Mitchell R, Burnett S et al. Ultrasound guided needle biopsy of primary bone tumours.

  J Bone Joint Surg Br. 2000;82:50–54.

  Stoker DJ, Cobb JP, Pringle JAS. Needle biopsy of musculoskeletal lesions. A review of 208 procedures.

  J Bone Joint Surg Br. 1991;37:498–500.

   

  Open biopsy of bone‌

  Preoperative planning

  Indications

• Patients who are not suitable for a needle biopsy.

• Patients in whom tissue from a needle biopsy was insufficient to make the diagnosis.

   

  Open biopsy can be incisional where a sample of the lesion is taken or it can be excisional where the whole lesion is removed. Excisional biopsy is generally reserved for lesions which, on radiology, have diagnostic features of a benign lesion.

   

  Contraindications

  Lesions where a satisfactory needle biopsy can be performed.

   

  Consent and risks

  • Neurovascular injury

  • Infection

  • Seeding of the tumour

  • Unexpected histological result with need for further surgery

   

   

  Templating

  The incision should be planned with the surgeon and be made in the line of the surgical approach that will be used to remove the tumour.

  Thought should be given as to how to localise the tumour, e.g. with image intensifier intraoperatively if necessary.

   

  Anaesthesia and positioning

  Regional/general anaesthesia and patient positioned to enable good access.

   

  Surgical technique

  Landmarks and incision

  The incision should be made in line with an extensile approach that can be utilised at the time of definitive surgery to excise the biopsy tract together with the specimen.

   

  Dissection

  Dependent on the location.

   

  Technical aspects of procedure

  It is important to minimise potential complications of biopsy such as infection and haematoma as a poorly performed biopsy carries significant morbidity. When a tourniquet is used, the limb should be elevated rather than exsanguinated and the tourniquet deflated prior to closure to ensure adequate haemostasis. If a drain is used, the exit point should be in the line of any further incision.

  Only one compartment of the limb should be violated during the approach. Muscles should be split and meticulous haemostasis applied to minimise haematoma formation and spread of fluid through tissue planes. The area to be biopsied should be carefully exposed, taking care not to disrupt the capsule or expose more of the tumour than is necessary. If a capsule is opened then it should be closed carefully.

   

  A representative sample of tissue should be taken to include the transition from normal to abnormal tissue if possible. If there is any doubt then frozen section should be undertaken to ensure a diagnostic specimen.

   

  Closure

  Routine.

   

  Postoperative instructions

  Neurovascular observations.

   

  Recommended references

  Ashford RU, McCarthy SW, Scolyer RA et al. Surgical biopsy with intra-operative frozen section. An accurate and cost-effective method for diagnosis of musculoskeletal sarcomas. J Bone Joint Surg Br. 2006;88:1207–1211.

  Mankin HJ, Lange TA, Sapnnier SS. The hazards of biopsy in patients with malignant primary bone and soft tissue tumours. J Bone Joint Surg Am. 1982;64:1121.

  Pollock RC, Stalley PD. Biopsy of musculoskeletal tumours – Beware. A NZ J Surg. 2004;74:516–519.

   

  Excision of benign bone tumour‌

  Preoperative planning

  Common indications

• Impending fracture, e.g. aneurysmal bone cyst

• To prevent further bony destruction and/or functional loss in aggressive lesions – e.g. giant cell tumour

• Mechanical symptoms – osteochondroma

• Pain – osteoid osteoma

• Risk of malignant transformation

   

  Contraindications

  No definitive characterisation of the lesion on either imaging or pathology.

   

  Consent and risks

  Depend on anatomical location and pathology of the lesion.

   

   

  Templating

  The approach depends on access required to perform resection while also taking into consideration any future potential reconstructive procedures.

   

  Anaesthesia and positioning

  Usually general anaesthesia and routine positioning.

   

  Surgical technique Landmarks and incision As per preoperative plan.

   

  Dissection

  The exposure is dependent on the anatomical location and whether the plan is to perform curettage of the lesion (intralesional excision) or to excise it (marginal excision) and reconstruct it. It is unwise to attempt tumour excision and reconstruction through ‘minimally invasive’ approaches.

   

  Technical aspects of procedure

  Again, these depend on procedure and location. If en bloc resection is planned then reconstruction options need to be available, including any autograft or allograft necessary, in conjunction withanyhardwareforfixation. If curettageisplanned, graftor adjuvant treatments, such as cement, liquid nitrogen or phenol, may be required to fill/treat the resulting cavity.

  Necessary imaging modalities need to be available, such as computed tomography for localisation of an osteoid osteoma or image intensifier to localise a larger lesion.

   

  Closure

  Routine – procedure dependent.

   

  Postoperative care and instructions

• Routine

• Weightbearing and physiotherapy regimen – depend on procedure

   

  Recommended reference

  Malawer MM, Dunham W. Cryosurgery and acrylic cementation as surgical adjuncts in the treatment of aggressive (benign) bone tumours. Clin Orthop Relat Res. 1991;262:42.

   

  Bone cyst curettage with or without bone graft‌

  Preoperative planning

  Indications

• Risk of fracture or repeated fracture.

• Failure of other methods of treatment, such as a steroid injection into the cyst.

 

Contraindications

If radiology is not classical of a bone cyst, then histopathological diagnosis should be sought.

 

Consent and risks

• General risks and that of recurrence

• Depend on the location

 

 

Operative planning

Planning of the approach to allow good access to the whole cyst while not threatening the physis or nearby neurovascular structures.

 

Anaesthesia and positioning

General anaesthesia; positioning depends on the access required.

 

Surgical technique

Landmarks and incision

Utilisation of a recognised surgical approach in most cases.

 

Dissection

Dissection to bone, following described approaches and avoiding neurovascular structures, exposing the periosteum over the length of the cyst. The image intensifier is often necessary to locate the lesion or to confirm the position and extent of the cavity.

 

Technical aspects of procedure

Once the cyst has been located, a 2.5 mm drill bit is used to drill (at 5–10 mm intervals) the outline of a cortical window through which curettage is going to take place. By drilling, it confirms the presence of the cyst and avoids stress risers in the bone or the propagation of a fracture. The holes are joined up with a small osteotome or saw blade (Figure 2.3).

 

 

(a)

(b)

2.5 mm drill holes

5–10 mm apart

 

Extent of cyst

Holes joined with osteotome to create a window

 

 

Figure 2.3 (a,b) Technique for making a cortical window for curettage of a bony lesion.

 

Once the cyst is entered, thorough curettage can take place, attempting to remove tissue from all bone surfaces. A communication is made from the cyst to the medulla of the bone to allow the cyst to fill with blood (which reduces recurrence rate). Screening with an image intensifier (Figure 2.4) confirms that the whole cavity has been treated.

 

 

 

 

 

Figure 2.4 Screening the extent of the cavity to be curetted.

 

If the cyst is close to the growth plate, the cortical window is made distant to the physis; curettage of the growth plate is avoided as this may lead to a growth disturbance. The cyst can be grafted with a cancellous or corticocancellous autograft from the ileum, tibia or fibula. An allograft or synthetic graft may also be used to fill the defect.

The cortical window, if large enough, may be replaced and held with a screw or periosteal sutures.

 

Closure

Routine.

 

Postoperative instructions

Restoration of the range of motion of neighbouring joints is undertaken as soon as possible. Weightbearing status is dependent on the anatomical location and the size of the defect.

 

Recommended reference

Aboulafia AJ, Temple HT, Scully SP. Surgical treatment of benign bone tumors. Instr Course Lect.

2002;51:441–450.

 

Malignant tumour principles‌

Preoperative planning

Common indications

• Excision of an isolated primary tumour

• Excision of a primary tumour with metastatic disease depending on life expectancy

• Excision of isolated metastases

• Excision of a fungating tumour for local control

• Excision of tumour recurrence

   

  Contraindications

• Poor life expectancy

• Co-morbidities

• Malignancies treatable by chemotherapy alone such as lymphoma

   

  Consent and risks

  Depend on the anatomical location and magnitude of the procedure.

   

   

  Operative planning

  The tumour, the surrounding compartments and the whole bone must be satisfactorily imaged to allow adequate planning of the procedure and reconstructive method. This will usually involve plain films, computed tomography and magnetic resonance imaging.

  Planning of the surgical approach needs to enable sufficient access to remove the tumour and any structures to be sacrificed to ensure tumour clearance with wide margins, which means removal of a layer of the normal tissue surrounding the whole tumour (Figure 2.5).

  Structures at risk and the method of reconstruction have to be considered. Surgical approaches that are not routinely used may have to be employed and plastic surgical techniques may be necessary to provide soft tissue coverage after resection. In cases of highly vascular tumours or particularly renal and thyroid metastases, preoperative embolisation should be considered to reduce the intraoperative blood loss.

   

  Anaesthesia and positioning

  General or regional anaesthesia as appropriate and positioning to allow sufficient access.

   

  Surgical technique

  Landmarks and incision

  Depend on anatomical location of the tumour.

   

  Marginal excision

  Wide excision

  Radical excision

  Intralesional

  excision

   

   

   

  Figure 2.5 Intralesional, marginal, wide and radical margins for the excision of bone and soft tissue tumours. (Note the diagram shows a soft tissue lesion.)

   

  Dissection

  Dissection must enable removal of the tumour en bloc with a layer of normal tissues surrounding it to provide a wide margin. In some cases neurovascular structures may be preserved and therefore a marginal excision around these structures is performed. Postoperatively, an opinion regarding adjuvant therapy is obtained. However, if cure is sought, and the neurovascular structures are involved then they must be sacrificed. This may mean an amputation or reconstruction of the vessels. In certain soft tissue sarcomas, a course of preoperative radiotherapy may be advocated, and repeat imaging is acquired prior to surgical excision. Wound complication rates are higher in this group of patients.

   

  Technical aspects of procedure

  Margins and structures to be sacrificed can usually be anticipated from good-quality imaging. However, during the procedure the surgeon needs to decide, based on experience and the feel of the tissues, what has to be sacrificed, in conjunction with the imaging.

  The parts of the procedure that have the easiest anatomical access are undertaken first. Samples from remaining surrounding tissues are sent for histology if the resection margin is questionable. Intraoperative frozen section can be used to ensure an adequate resection margin if there is any doubt.

   

  The wound should be thoroughly washed with water (as water is highly hypotonic, it may aid in lysis of any spilled tumour cells) after removal of the tumour. If any spillage of the tumour or invasion of the capsule of the tumour has taken place intraoperatively then after washing, new instruments, gloves and gowns should be used for reconstruction and/or closure.

  If it is found postoperatively on histological examination that an inadequate margin has been taken then a repeat wide local excision should be considered.

   

  Closure

• Routine closure

• Drains to be placed in line of incision to facilitate tract excision if re-excision is necessary

   

  Postoperative care and instructions

• Routine

• Weightbearing and physiotherapy – depend on procedure

 

Recommended reference

Enneking WF, Maale GE. The effect of inadvertent tumour contamination of wounds during the surgical resection of musculoskeletal neoplasms. Cancer. 1988;62:1251.

 

Recommended references (for whole chapter)

General information relating to all of the topics in this chapter can be found in the following:

Enneking WF. Musculoskeletal Tumour Surgery. New York, NY: Churchill Livingstone, 1983.

Malawer MM, Sugarbaker PH. Musculoskeletal Cancer Surgery Treatment of Sarcomas and Allied Diseases.

Dordrecht: Kluwer Academic, 2001.

O’Sullivan B. Preoperative versus postoperative radiotherapy in soft tissue sarcoma of the limbs: A randomised trial. Lancet. 2002;359(9325):2235–2241.

Sim FH, Frassica FJ, Frassica DA. Soft tissue tumours: Diagnosis, evaluation and management. J Am Acad Orthop Surg. 1994;2:202–211.

 

Viva questions‌

1. What do you understand about the principles of biopsy of a tumour?

2. How would you perform a biopsy of a bony lesion?

3. How would you perform a biopsy of a soft tissue lesion?

4. How would you choose between a needle biopsy and an open biopsy?

5. What must be avoided during biopsy?

6. How would you make a cortical window in bone?

7. How would you treat a benign bone cyst?

8. What are the indications for excision of a benign bone tumour?

 

 

1. What considerations have to be taken into account when excising a benign bone tumour?

2. What are the indications for excision of a malignant bone tumour?

3. How would you plan the excision of a malignant bone tumour?

4. What are the principles involved in the excision of a malignant bone tumour?

5. What is the difference between an open biopsy and an excision biopsy?

6. What does a marginal resection mean?

7. What is the difference between a wide and a radical resection?

8. How would you ensure that you have an adequate biopsy?

9. What do you understand by the term limb salvage?

10. Why might it not be possible to salvage a limb?

11. Where and by whom should a biopsy be carried out