Principles of tumor biopsy.

Tumor biopsy is the cornerstone of sound therapeutic decision making in oncology. Although there are multiple ways to obtain a biopsy from any given tumor, each individual procedure requires careful planning to ensure that the optimal treatment course is not compromised. Knowledge of the principles and techniques underlying biopsy is imperative to ensure an accurate diagnosis with minimal morbidity. This article describes the principles of biopsy and commonly used sampling techniques and where these procedures are most applicable. Appropriate tissue handling, interpretation of results, and some special techniques are also described.