Piya Kiatisevi 1, Torsten Nielsen 2, Malcolm Hayes 2, Peter L Munk 3, Amy E LaFrance 4, Paul W Clarkson 4, Bassam A Masri 4 1 Orthopaedic Oncology Lerdsin Hospital, Institute of Orthopaedics, Lerdsin Hospital, Bangkok, Thailand 2 Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada 3 Department of Radiology, University of British Columbia, Vancouver, BC, Canada 4 Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada Saturday, November 15, 2008

Background Open biopsy is the historical gold standard for diagnosing bone and soft-tissue lesions  Highly accurate  16% complication rate  12% treatment altered  1.2% unnecessary amputation Mankin et al., J Bone Joint Surg Am. 1996;78(5):

Core Needle Biopsy (CNB) Increasingly accepted for the diagnosis of bone and soft-tissue lesions  Reduced morbidity, time and cost  Fewer complications Concerns remain regarding accuracy of CNB

Objectives To assess and compare :  Core Needle Biopsy (CNB)  Open Biopsy (OB)  Fine Needle Aspiration (FNA) Diagnostic rate Accuracy for  Distinguishing benign vs. malignant  Histological diagnosis  Distinguishing low vs. high grade sarcoma

Materials and Methods Prospectively collected database  286 biopsies in 282 patients   165 males, 117 females  Mean age 51 yrs (range yrs) Biopsy compared to final pathology Included biopsies performed prior to referral but slides were re-reviewed by an experienced MSK pathologist

Our Practice  Patients are assessed in MSK surgical clinic  Site for CNB is marked with indelible marker  Image-guided biopsy performed by radiologist within pre-marked biopsy site  10mm biopsy incision so site is identifiable for definitive resection

Our Practice  If core needle biopsy is non-diagnostic, then proceed with open biopsy  Biopsy track excised en bloc with tumour during definitive resection

229 CNB 32 OB 25 FNA 286 biopsies Biopsy Types

Tumour typeBoneSoft-tissueTotal Benign tumours Sarcomas Non-sarcoma malignancies Tumour-like lesions11112 Total Types of Lesions

Results

Diagnostic Rate 92% 100% 72%

Non-diagnostic Specimens BenignMalignant Bone (B)64 Soft-tissue (ST)71 CNB (18/229 = 8%) BenignMalignant Bone (B)00 Soft-tissue (ST)61 FNA (7/25 = 28%)

Accuracy for Distinguishing Benign vs. Malignant Accuracy 89% 97% 68%

Benign (at biopsy)  Malignant (final pathology) CNB (n=229) 6 Benign lipomatous tumour  Well-differentiated liposarcoma (ST) 1 Fracture healing  Adenocarcinoma metastasis (B) OB (n=32) 1 Leiomyoma  Leiomyosarcoma (ST) FNA(n=25) 1 Mature fat  Well-differentiated liposarcoma (ST) Incorrect Diagnosis of Benign vs. Malignant

Malignant (at biopsy)  Benign (final pathology) CNB (n=229) 1 Lymphoma of ilium  Osteomyelitis (B) OB (n=32) 0 FNA (n=25) 0 Incorrect Diagnosis of Benign vs. Malignant

Accuracy for Histological Subtype Accuracy 70% 81% 40%

TypeBoneSoft-tissueTotal Benign tumors Sarcoma Non-sarcoma malignancy Tumour-like lesions11112 Total Accuracy for Distinguishing Low vs. High Grade Sarcoma

Accuracy 90% 96% 72%

Low grade (at biopsy)  High grade (final pathology) CNB (n=92) 3 OB (n=24) 0 FNA (n=10) 2 High grade (at biopsy)  Low grade (final pathology) None 1 Osteosarcoma (B) 1 Liposarcoma (ST) 1 Ossifying fibromyxoid tumour (ST) 1 De-diff. Chondrosarcoma (B) 1 Myofibroblastic sarcoma (ST) Incorrect Diagnosis of Low vs. High Grade Sarcoma

Typen Diagnostic Rate Accuracy for benign vs. malignant Accuracy for histological diagnosis Accuracy for low vs. high grade sarcoma CNB22992% 203/229 (89%) 161/229 (70%) 89/99 (90%) OB32100% 31/32 (97%) 26/32 (81%) 24/25 (96%) FNA2572% 17/25 (68%) 10/25 (40%) 8/11 (72%) Discussion

Perform CNB with care on fatty lesions

Conclusion Core needle biopsy is accurate for determining:  Benign vs. malignant  Histological subtype  Low vs. high grade for sarcoma Advantages of core needle biopsy  Fewer complications  Reduced cost of treatment  High diagnostic accuracy

Recommendations CNB be used routinely for diagnosis, whenever possible Open biopsy reserved for use when CNB is non- diagnostic Given its high inaccuracy, FNA is not indicated for diagnosing musculoskeletal lesions in the extremities

Thank you Orthopaedic Oncology Lerdsin Hospital, Bangkok, Thailand The University of British Columbia, Vancouver, BC, Canada

Type CNB (N= 229) OB (N=32) FNA (N=25) Benign bone tumours5-- Malignant bone tumours2-- Benign soft-tissue tumours5-6 Malignant soft-tissue tumours1-1 Carcinoma and myeloma2-- Tumour-like lesions3-- Total18-7 Non-diagnostic rate8%0%28% Diagnostic rate92%100%72% Non-diagnostic Specimens