Biopsy Principles and Techniques in Orthopaedic Oncology

Biopsy is the definitive diagnostic procedure for a suspected bone or soft tissue tumour, and its technique and timing are critical. An improperly performed biopsy compromises subsequent treatment, increases morbidity, and can force an amputation in a limb that would otherwise have been salvageable. An inappropriate biopsy is the most common referral error.

Two multi-institutional studies by Mankin, fourteen years apart, put numbers to that and established the principle the rest of this page follows.

Planning Before Any Tissue Is Taken

Finish the imaging first. Plain films, MRI and a CT chest come before the biopsy, and the case is reviewed by radiology, pathology and oncology together. The images are what the tract is planned from, so they are read with the anatomy of the eventual resection in mind.

Involve the definitive surgeon. Ideally the surgeon who will perform the resection performs the biopsy; at the very least the plan is discussed with a tumour centre and the approach agreed with them before anyone books the list.

Then execute it properly. Core needle biopsy for most lesions, a longitudinal approach parallel to the neurovascular structures, a single compartment, a tract lying entirely within the planned resection field, and meticulous haemostasis so that no haematoma forms.

Why the Tract Matters

The biopsy tract is contaminated with tumour cells from the moment it is made, and it is excised en bloc with the tumour at the definitive resection. Every rule below follows from that single fact. Poor technique does specific damage:

• Seeds tumour cells into the surrounding tissue through the haematoma
• Violates tissue planes, so the resection margins become unclear
• Contaminates additional compartments, forcing a wider resection
• Compromises neurovascular structures, precluding limb salvage
• Creates a skin bridge between the biopsy and the tumour that then needs grafting

Fine Needle Aspiration

Technique. A 22-25 gauge needle by palpation or under image guidance, with multiple passes, typically four to six; the material is smeared and either air-dried or alcohol-fixed. It yields cells, not tissue.

What that costs. Cytology cannot assess architecture, and architecture is what the grading and subtyping of a bone or soft tissue sarcoma depend on. Sensitivity for sarcoma is 60-80%, the inadequate specimen rate 10-20%, there is little tissue left for immunohistochemistry or molecular studies, and the reading is reader-dependent, requiring an expert cytopathologist.

Where it still earns its place. FNA is minimally invasive and office-based, can sample several sites, carries minimal contamination risk and turns around quickly. Use it to confirm metastatic disease when the primary cancer is known, to diagnose lymphoma alongside flow cytometry, and for initial triage in resource-limited settings. For a primary sarcoma diagnosis, core needle biopsy is superior.

Core Needle Biopsy

Core needle biopsy is the first-line biopsy technique for most suspected bone and soft tissue tumours. It preserves the tissue architecture, so the tumour can be graded histologically; several cores give enough material for immunohistochemistry; the tract is small and easily excised; image guidance puts the needle in viable tumour rather than necrosis; and it is done as an outpatient with lower morbidity than an open biopsy.

Its limits. The tissue volume is small, so sampling error is real and a heterogeneous tumour may be under-represented. The slides need an expert musculoskeletal pathologist, frozen section cannot be performed reliably on cores, and a non-diagnostic result means repeating the biopsy. The radiologist taking the cores must also know the planned approach and the resection field, which means a conversation with the surgeon before the needle goes in.

Incisional Biopsy

An open incisional biopsy takes a block of tissue through a limited surgical incision without removing the lesion. It is second-line, and its indications are specific:

• A non-diagnostic needle biopsy, whether inadequate or inconclusive
• A heterogeneous tumour with large areas of necrosis, where a larger sample is needed
• A bone lesion requiring instrumentation, where hard cortex prevents needle access
• Suspected lymphoma, which needs tissue architecture and fresh tissue for flow cytometry
• Surgeon preference, when the definitive surgeon prefers to place the tract themselves

Excisional Biopsy

Excisional biopsy removes the whole lesion with a margin of normal tissue, and in musculoskeletal oncology its place is very limited: a small superficial lesion under 3cm with low suspicion of sarcoma, a subcutaneous lipoma of typical appearance that is mobile and soft, a pedunculated lesion such as a presumed skin tag or neurofibroma, or a patient who prefers complete removal when a benign diagnosis is likely.

Do not excise a mass that is deep to fascia (an unacceptable contamination risk), greater than 5cm (this violates oncological principles), firm or fixed (which suggests malignancy), one with imaging features of sarcoma (excision here is an inappropriate marginal excision), or a bone lesion with aggressive features (which needs staging and planning first).

Which Lesions Need Tissue

Not every bone or soft tissue lesion needs a biopsy. Many benign lesions are diagnosed with certainty from the imaging and the clinical picture, and biopsying them adds risk without adding information.

The features that force tissue. Beyond those scenarios, the findings that convert an observed lesion into a biopsied one are:

• A moth-eaten or permeative pattern of bone destruction, or a soft tissue mass arising alongside the bone lesion
• A lesion inappropriate for the patient's age, such as a lytic femoral lesion at 40
• Rapid growth or progression of symptoms, or atypical features that do not fit a benign diagnosis
• A firm, fixed or irregular soft tissue mass, or one that has recurred after a previous excision
• Pain or paraesthesia arising from the mass, or pain disproportionate to the imaging findings
• Tissue needed to direct treatment: establishing the diagnosis in a metastatic workup, planning neoadjuvant chemotherapy or radiotherapy, re-biopsy to monitor treatment response, uncertain imaging despite a full workup, or separating infection from tumour

When to Defer or Avoid Biopsy

Biopsy should be deferred or avoided in a small number of specific situations:

• Classic benign imaging, such as a pathognomonic fibrous cortical defect
• Vascular lesions, where the haemorrhage risk is real - consider embolisation first
• Inadequate imaging - complete the MRI and the staging studies first
• Suspected infection - aspirate for culture rather than biopsy
• Uncorrected coagulopathy, where the bleeding risk is too high
• A patient unfit for treatment, in whom the diagnosis will not change management

Lesions That Mimic Sarcoma

A defining biopsy error is treating a benign or non-neoplastic mimic as a sarcoma, or the reverse. Recognising the differential before the biopsy decides whether to biopsy at all, by what route, and where it should be done.

Algorithm

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Talking to the Pathologist

Call before the biopsy, not after it. The pathologist needs the patient's age and relevant history, the location and size of the lesion and the anatomic compartment it occupies, the imaging findings and the differential, and the clinical question being asked: primary tumour, metastasis or infection. Say whether fresh tissue is coming separately for culture, and whether a frozen section will be requested.

Why the phone call changes the result. Given the case in advance, the pathologist can prepare the appropriate fixatives and stains, plan ancillary studies such as immunohistochemistry and molecular work, arrange frozen section capability, and optimise specimen handling. Poor communication with pathology is a common cause of a non-diagnostic biopsy.

From Specimen to Diagnosis

What Frozen Section Can and Cannot Do

It cannot make the diagnosis. Freezing disrupts the architecture and loses the cellular detail, so a frozen section cannot reliably identify the sarcoma subtype and cannot grade it. It also consumes tissue a small biopsy may not be able to spare, and the answer it gives is preliminary. Permanent sections with immunohistochemistry are what deliver the diagnosis.

What it is genuinely for. Frozen section has four appropriate uses:

• Confirming that diagnostic tissue has been obtained, rather than adipose, muscle or necrosis
• Ruling out infection, with a gram stain on the frozen material
• Confirming diagnostic material in a lesion that is difficult to reach again, such as spine or pelvis
• Triaging tissue for ancillary studies, such as flow cytometry for lymphoma

Ancillary Studies

Modern sarcoma diagnosis often requires studies beyond standard H&E microscopy.

The Four Error Categories

Mankin's series sorted biopsy failures into four recurring categories. Each has its own specific prevention.

What the errors cost. Beyond the wider resection or the amputation, a biopsy error buys re-operation, skin grafting and flap coverage, definitive treatment waits while the wound heals, and the tumour progresses during the delay. That is the argument for these biopsies being performed at specialised centres, by surgeons with oncological training.

Complications of the Biopsy Itself

Early. Haematoma is the most common, and here it is more than a wound problem: it carries tumour cells out into the surrounding tissue, which is why haemostasis is meticulous and a compression dressing goes on. Infection mimics tumour progression and delays definitive treatment, so sterile technique and prophylactic antibiotics matter. Fracture through a cortical window is prevented by keeping the window small, avoiding stress risers, and considering prophylactic fixation.

Late. Tumour seeding along the tract is why the tract is excised, and seeding into an adjacent compartment may preclude salvage altogether. A non-diagnostic result, from inadequate tissue or sampling error, means a repeat biopsy: image guidance, an adequate sample and a briefed pathologist are what prevent it.

The Unplanned ("Whoops") Excision

A specific and common referral disaster is the unplanned excision: inadvertent marginal or intralesional removal of an unsuspected sarcoma by a non-specialist who assumed the mass was benign. It is the surgical analogue of the biopsy errors.

Why it matters. The tumour has been shelled out without a margin, the whole surgical bed - including any drain sites and the haematoma - is contaminated, and the tissue planes are destroyed. It is exactly the situation Mankin warned against.

Residual disease is common and unpredictable. After an unplanned excision with apparently negative margins and no gross residual on examination or imaging, planned re-excision still finds residual sarcoma in roughly a third of cases (Noria), and this cannot be predicted by tumour size, grade or the interval since surgery.

Management. Restage with MRI of the operative bed plus a CT chest, discuss at the sarcoma multidisciplinary team meeting, and perform a planned wide re-excision of the entire previous surgical field, taking scar, drain tracts and contaminated tissue en bloc. Adjuvant or neoadjuvant radiotherapy is frequently added given the contaminated field. Re-excision is often still margin-positive, and local recurrence is higher than for tumours resected correctly the first time.

Global Epidemiology and Centralisation

Soft tissue sarcomas account for roughly 1% of adult malignancies and primary bone sarcomas for around 0.2%, with combined incidences in the region of 4-5 and 0.8-1 per 100,000 per year respectively across high-income registries - both are rare cancers for which centralised, multidisciplinary care is the international standard (ESMO-EURACAN-GENTURIS soft tissue/visceral sarcoma and bone sarcoma guidelines, Ann Oncol 2021). Across all major frameworks the consistent message is identical to Mankin's: biopsy should be planned and ideally performed at, or in agreement with, the sarcoma reference centre that will deliver definitive treatment.

Side-by-Side Guideline Positions on Biopsy

Practice Variation and Registries

Real-world practice still diverges from guideline ideals. Population and centre-based series consistently show that a substantial minority of sarcomas are still subjected to an unplanned ("whoops") excision before referral, and that biopsy performed outside a sarcoma centre carries 2-12 times the error/complication rate (Mankin, J Bone Joint Surg Am 1982 and 1996). National sarcoma registries and reference-centre networks (for example UK and European networks, and the Australian sarcoma services) are used to audit unplanned-excision rates, time-to-specialist-review and diagnostic accuracy as quality indicators.

Regional Access Notes

Reference-centre models operate worldwide, each providing multidisciplinary sarcoma clinics, limb-salvage expertise and trial access, with telehealth review for regional and rural patients. Examples include specialist sarcoma units in the UK (BSG/NICE designated centres), EURACAN reference networks in Europe, NCCN-aligned sarcoma centres in North America, and Australian sarcoma services (e.g. Peter MacCallum Cancer Centre, Chris O'Brien Lifehouse, Princess Alexandra Hospital and Royal Adelaide Hospital). Across systems, the rate-limiting step for good outcomes is the same: getting the patient to an expert MDT before the first biopsy.

This section provides exam-focused practice points.

CT-Guided Core Biopsy

Ultrasound-Guided Core Biopsy

Fluoroscopy-Guided Biopsy

Limited role in musculoskeletal oncology:

• Primarily for spine lesions (transpedicular approach)
• Real-time guidance for needle placement
• Lower radiation than CT
• 2D imaging only (less accurate than CT 3D)

Collaboration with Tumor Centers

All suspected sarcomas should be discussed with a tumor center before biopsy. Referral is indicated for suspected bone sarcoma, soft tissue mass greater than 5cm or deep to fascia, imaging features of malignancy, failed primary treatment, complex anatomy (spine, pelvis), and metastatic disease staging.

The optimal referral is BEFORE biopsy. Many tumor centers prefer to perform the biopsy themselves. Referral after an inappropriate biopsy results in delayed treatment, increased morbidity, and potentially worse outcomes.

Tumor centers provide access to multidisciplinary tumor boards including orthopaedic oncologist, musculoskeletal radiologist and pathologist, medical oncologist, radiation oncologist, and plastic surgeon. Benefits include expert consensus, coordinated treatment planning, protocol-based therapy, access to clinical trials, and improved outcomes.

1. Mankin HJ, Lange TA, Spanier SS. The hazards of biopsy in patients with malignant primary bone and soft-tissue tumors. J Bone Joint Surg Am. 1982;64(8):1121-1127.

2. Hau A, Kim I, Kattapuram S, et al. Accuracy of CT-guided biopsies in 359 patients with musculoskeletal lesions. Skeletal Radiol. 2002;31(6):349-353.

3. Welker JA, Henshaw RM, Jelinek J, et al. The percutaneous needle biopsy is safe and recommended in the diagnosis of musculoskeletal masses. Cancer. 2000;89(12):2677-2686.

4. Noria S, Davis A, Kandel R, et al. Residual disease following unplanned excision of soft-tissue sarcoma of an extremity. J Bone Joint Surg Am. 1996;78(5):650-655.

5. Skrzynski MC, Biermann JS, Montag A, Simon MA. Diagnostic accuracy and charge-savings of outpatient core needle biopsy compared with open biopsy of musculoskeletal tumors. J Bone Joint Surg Am. 1996;78(5):644-649.

6. Dupuy DE, Rosenberg AE, Punyaratabandhu T, et al. Accuracy of CT-guided needle biopsy of musculoskeletal neoplasms. AJR Am J Roentgenol. 1998;171(3):759-762.

7. Fraser-Hill MA, Renfrew DL, Hilsenrath PE. Percutaneous needle biopsy of musculoskeletal lesions. 2. Cost-effectiveness. AJR Am J Roentgenol. 1992;158(4):813-818.

8. Heslin MJ, Lewis JJ, Woodruff JM, Brennan MF. Core needle biopsy for diagnosis of extremity soft tissue sarcoma. Ann Surg Oncol. 1997;4(5):425-431.

9. Pohlig F, Kirchhoff C, Lenze U, et al. Percutaneous core needle biopsy versus open biopsy in diagnostics of bone and soft tissue sarcoma: a retrospective study. Eur J Med Res. 2012;17:29.

10. Ray-Coquard I, Montesco MC, Coindre JM, et al. Sarcoma: concordance between initial diagnosis and centralized expert review in a population-based study within three European regions. Ann Oncol. 2012;23(9):2442-2449.

11. Mitsuyoshi G, Naito N, Kawai A, et al. Accurate diagnosis of musculoskeletal lesions by core needle biopsy. J Surg Oncol. 2006;94(1):21-27.

12. Strauss DC, Qureshi YA, Hayes AJ, et al. The role of core needle biopsy in the diagnosis of suspected soft tissue tumours. J Surg Oncol. 2010;102(5):523-529.

13. Domanski HA, Akerman M, Carlén B, et al. Core-needle biopsy performed by the cytopathologist: a technique to complement fine-needle aspiration of soft tissue and bone lesions. Cancer. 2005;105(4):229-239.

14. Adams SC, Potter BK, Pitcher DJ, Temple HT. Office-based core needle biopsy of bone and soft tissue malignancies: an accurate alternative to open biopsy with infrequent complications. Clin Orthop Relat Res. 2010;468(10):2774-2780.

15. Åkerman M, Domanski HA. The cytology of soft tissue tumours. Monogr Clin Cytol. 2003;16:1-116.

16. Mankin HJ, Mankin CJ, Simon MA. The hazards of the biopsy, revisited. Members of the Musculoskeletal Tumor Society. J Bone Joint Surg Am. 1996;78(5):656-663. PMID: 8642021.

17. Gronchi A, Miah AB, Dei Tos AP, et al. Soft tissue and visceral sarcomas: ESMO-EURACAN-GENTURIS Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2021;32(11):1348-1365. PMID: 34303806.

18. Strauss SJ, Frezza AM, Abecassis N, et al. Bone sarcomas: ESMO-EURACAN-GENTURIS-ERN PaedCan Clinical Practice Guideline for diagnosis, treatment and follow-up. Ann Oncol. 2021;32(12):1520-1536. PMID: 34500044.

Key Regional References

19. Australia and New Zealand Sarcoma Association (ANZSA). Guidelines for the management of soft tissue sarcoma. Available at: www.anzsa.org.au

20. Cancer Australia. Optimal care pathway for people with sarcoma. Canberra: Cancer Australia, 2016.

21. Victorian Comprehensive Cancer Centre. Sarcoma service referral guidelines. Melbourne: Peter MacCallum Cancer Centre, 2020.

Suggested Reading

• Enneking WF. Musculoskeletal Tumor Surgery, Volume 1. Churchill Livingstone; 1983. [Classic text on biopsy principles]
• Simon MA, Springfield D. Surgery for Bone and Soft-Tissue Tumors. Lippincott-Raven; 1998. [Comprehensive operative techniques]
• Grimer RJ, Carter SR, Pynsent PB. The cost-effectiveness of limb salvage for bone tumours. J Bone Joint Surg Br. 1997;79(4):558-561.