[How to determine whether a compressive spinal fracture was caused by osteoporosis or multiple myeloma].

The most common cause of compressive spinal fractures in older women is undoubtedly senile osteoporosis, while less common causes are malignant diseases which metastase into the skeleton and multiple myeloma focally or diffusely infiltrating the skeleton. Targeted biopsy in the hands of an experienced radiologist is the fastest diagnostic method which has the potential to detect the exact cause of the compressive fracture. We describe a case of monoclonal gammopathy in which only a biopsy using CT-guided puncture of the compressed vertebra showed a symptomatic multiple myeloma requiring overall treatment. Up to the time of the targeted biopsy, the patient had wrongly been classified as a case of monoclonal gammopathy of undetermined significance, and later as a case of stage IA asymptomatic multiple myeloma. The aim of the paper is to draw attention to the need for early invasive diagnostic intervention in unclear cases.