Needle-track metastasis after transthoracic needle biopsy.
Ayar D, Golla B, Lee JY, Nath H
Metastasis along the needle track (NTM) after a transthoracic needle
biopsy (TNB) is considered a very rare complication. A survey of the membership
of the Society of Thoracic Radiology and a review of the English-language
literature were conducted to assess the incidence of this complication
and its predisposing factors and natural history. A questionnaire was sent
to all radiology departments in the United States and Canada that had a
senior member of the Society of Thoracic Radiology. The total number of
TNB between 1978 and 1993 and occurrences of NTM were elicited. If an NTM
was encountered, information on the size of the nodule, proximity to the
pleura, histology, size of the biopsy needle, and the interval between
biopsy and NTM and outcome of the patient was elicited. The incidence of
NTM was estimated using binomial proportions. Results of the literature
survey were tabulated to provide similar information. One hundred sixty-five
questionnaires were mailed and 75 responses were received. Approximately
68,346 TNB were reported. Five departments reported a total of eight NTM,
resulting in an incidence of 0.012%. The average interval between TNB and
NTM was 2.6 months. There were no predictable risk factors. The outcome
was known in only 11 patients; 4 patients died by the time of reporting
(2 after 14 months and 1 each after 6 and 9 months). From the results of
this survey, the incidence of NTM after TNB is approximately 0.012%. This
small risk is random and unavoidable.
