Inadequate fine needle aspiration biopsy samples: pathologists versus other specialists

Fine needle aspiration biopsy (FNAB) is a simple, sensitive, quick and inexpensive method in which operator experience is essential for obtaining the best results.

A descriptive study in which the aspiration biopsy cases of the Pathology and Cytopathology Service of the University Hospital of the UANL (2003-2005) were analyzed. These were divided into three study groups: Group 1, FNAB performed by a pathologist; Group 2, FNAB performed by specialists who are not pathologists, Group 3, FNAB guided by an imaging study with immediate evaluation by a pathologist. The samples were classified as adequate and inadequate for diagnosis, the organ, the size and characteristics of the lesions were taken into consideration.

A total of 1905 FNAB were included. In Group 1: 1347 were performed of which 1242 (92.2%) were adequate and 105 (7.7%) were inadequate. Of the 237 from Group 2, 178 were adequate (75.1%) and 59 inadequate (24.8%); in Group 3 there were 321 of which 283 (88.1%) were adequate and 38 (11.8%) inadequate. A statistically significant difference was found between FNAB performed by Group 1 (p< 0.001) and the other groups. A multivariate analysis was done where the organ punctured, the study groups, the size and characteristics of the lesion by study group were compared, finding that the most important variable was the person who performed the procedure.

The experience and training of the person performing the aspiration biopsy, as well as immediate evaluation of the material when it is guided, substantially reduces the number of inadequate samples, improving the sensitivity of the method as well as reducing the need for open biopsies to reach a diagnosis.