What is a common reason for obtaining a nondiagnostic biopsy sample?

• A. Only periosteal reactive bone is sampled rather than the medullary cavity, where the primary neoplastic process resides.
• B. Biopsy sample contaminated.
• C. The patient moved during sampling.
• D. The lesion is too small to sample.

Answer: (A)

Sampling the correct tissue region is essential for a diagnostic bone biopsy. In many bone lesions, the neoplastic cells reside within the medullary cavity, not on the surface. If the biopsy needle only grabs periosteal reactive bone or the outer rim, you may collect non-specific tissue that shows reactive changes or normal periosteum, which doesn’t reveal the underlying tumor. That mismatch between where the disease is and what’s sampled leads to a nondiagnostic result, even though the procedure was technically successful.

Imaging guidance and targeted sampling help ensure you obtain material from the lesion’s intracavitary portion rather than the reactive outer layer. While issues like sample contamination, motion, or a very small lesion can also cause nondiagnostic results, they are less directly tied to the fundamental reason this question highlights: sampling the wrong tissue compartment.