Aspiration biopsy of the spine is a valuable although not an infallible method of obtaining a diagnosis in obscure lesions of the spine. It must be remembered that, since small bits of tissue are obtained through a partially blind approach, a negative diagnosis in many cases simply indicates a failure to aspirate pathological tissue and does not necessarily imply an absence of pathology. The pathology laboratory should not be criticized for simply reporting what is seen on the slides.

It is suggested that the procedure be used more widely—together with laboratory, clinical, and roentgenographic aids in obscure cases. More than ordinary caution should be exercised to observe the rules of surgical technique, judgment, and interpretation. The anatomy of the spine should be kept in mind and the technique which has been developed through trial and error should be followed carefully. We believe that, if the patient has been anaesthetized, he will be subject to less hazard from possible injury to vital parts. If possible, the unhappy experience of losing tissue after it has been extracted must be avoided by careful labeling and cooperation with the pathology department and the laboratories.

A small but interesting series of cases have been observed. In many of these cases, diagnosis, at least in our hands, would not have been possible had we not been able to examine the tissue directly obtained from the pathologically involved area.