Current Concepts in the Biopsy of Musculoskeletal Tumors : AAOS Exhibit Selection

Biopsy tissue can be obtained through a fine needle, a wider coring needle, or through an open surgical incision. Though much literature exists regarding the diagnostic yield of these techniques individually, none compare accuracy of diagnosis in the same mass. We asked how the diagnostic accuracy of fine-needle aspiration, core biopsy, and open surgical biopsy compare in regard to identifying malignancy, establishing the exact diagnosis, and guiding the appropriate treatment of soft tissue masses. We prospectively studied 57 patients with palpable extremity soft tissue masses, performing fine-needle aspiration, followed by core biopsy, followed by surgical biopsy of the same mass. Open surgical biopsy was 100% accurate on all accounts. With regard to determining malignancy, fine-needle aspiration and core biopsy had 79.17% and 79.2% sensitivity, 72.7% and 81.8% specificity, 67.9% and 76% positive predictive value, 82.8% and 84.4% negative predictive value, and an overall accuracy of 75.4% and 80.7%, respectively. In regard to determining exact diagnosis, fine-needle aspiration had a 33.3% accuracy and core biopsy had a 45.6% accuracy. With regard to eventual treatment, fine-needle aspiration was 38.6% accurate and core biopsy was 49.1% accurate. In soft tissue mass diagnosis, core biopsy is more accurate than fine-needle aspiration on all accounts, and open biopsy is more accurate than both in determining malignancy, establishing the exact diagnosis, and the guiding appropriate treatment.

Percutaneous needle biopsy has many advantages over open biopsy in the treatment of neoplasms. However, the accuracy of needle biopsy in the diagnosis of musculoskeletal lesions has not yet been established. Here, we evaluate the accuracy and limitations of the procedure for musculoskeletal lesions. The diagnoses of 163 needle biopsies (bone, 91; soft tissue, 72) performed on 157 consecutive patients using a Jamshidi needle or an Ostycut needle for bone lesions, or a Tru-cut needle for soft tissue lesions were compared with the final diagnoses made by open biopsy and/or a definitive operation. One hundred forty-three specimens (88%) were determined to be adequate for histological examination. Obtaining undamaged cores from very hard bony lesions or sclerotic cyst walls proved difficult. A pathologist with experience in musculoskeletal lesions was able to differentiate malignant tumors from benign lesions in 97% of the cases (bone, 100%; soft tissue, 94%) and arrive at a specific diagnosis in 88% (bone, 96%; soft tissue, 78%) when adequate cores were obtained. Differentiating a well-differentiated liposarcoma from a benign lipoma and inflammatory lesions from benign tumorous conditions, was difficult. The overall accuracy was 77% (bone, 85%; soft tissue, 68%). There was no morbidity related to the procedure. The results indicate that needle biopsy is safe and accurate for diagnosing musculoskeletal lesions. Copyright 2006 Wiley-Liss, Inc.