A seven-year review of spinal biopsy results at a single academic Center in South Africa

Abstract

Background: The ability to perform a consistently effective spinal biopsy that yields adequate specimen to make a diagnosis, without incurring  complications, is an essential skill required by a spinal surgeon.
Objective: To provide an institutional review of the spinal biopsy results, collected over a 7-year period, in 126 patients.
Methods: We performed a retrospective review of the laboratory results of 126 patients who had spinal biopsies performed at our institution over a 7-year period. The data collected and analyzed in this study included age, gender, type of biopsy performed, microbiology results, and histology results.
Results: Of the 126 spinal biopsies performed, 55/126 (44%) were performed for neoplastic disease, and 71/126 (56%) were performed for tuberculosis. High statistical significance was demonstrated between subject age and neoplastic/tuberculous diagnosis (p<0.001). In this study, 106/126 (84%) subjects had open biopsies and 20/126 (16%) subjects had percutaneous core needle biopsies. In our tuberculosis group we report that in 50/71 (70%) subjects the Zeels’ Nielsen (ZN) stain was negative and in 40/71 (56%) subjects the tuberculosis culture result was negative. Hence in approximately 50% of our 71 tuberculosis cases the diagnosis was made by histopathological diagnosis where in 34/71 (48%) subjects tuberculosis was confirmed by the presence of caseating granulomas, and in 37/71 (52%) subjects tuberculosis was suggested by granulomatous inflammation without caseation being present.
Conclusion: While an adequate spinal biopsy more reliably provides a useful histology result in neoplastic disease, in spinal tuberculosis there is only an approximately 50% yield on Zeels Nielsen staining and tuberculosis culture. Our study confirms the importance of the indirect  histopathological evidence of tuberculosis, which we found to often be all that was available to make the diagnosis.

Key words: Spinal tuberculosis, Spinal metastases, Biopsy results