[Metastases caused by fine needle puncture?].

Tumour cells appear spontaneously in the blood of tumour patients. However, the formation of metastases depends not only on the number of tumour cells, but also to a large degree on the defence status of the patient. According to the experiments presented here, fine needle puncture can slightly increase tumour cell migration. Tumour cells are carried through the puncture channel into the bloodstream; case reports show that in some cases the number of tumour cells mobilised in this manner may be sufficient to induce a metastatic growth at the site of puncture. However, practically all reported cases concerned advanced tumour stages. The puncture metastasis did not exercise any influence on the course of the disease or on the prognosis. The incidence of metastases in the puncture channel after fine needle biopsy of tumours of various organs is between 0.003 and 0.005% and is hence low. Nevertheless, indication for fine needle puncture of malignant processes should be considered very critically. However, if the use of the puncture leads one to expect therapeutic consequences that are of relevance for the patient, the doctor should not hesitate to employ this method which has a high informative value.