No Need to Delay Mammography After FNA, Study Shows

CARDIFF, Wales--Breast imaging studies can proceed immediatelyafter fine-needle aspiration (FNA) cytology without concern thatthe biopsy procedure will distort tissue architecture and compromisediagnostic accuracy, said Neil Fenn, MD, a breast disease specialistat the University of Wales.

In his study, only five of 168 women had tissue distortion onmammography performed after FNA, and only two of the five hadbreast imaging within 10 days of the biopsy. The findings stronglysuggest that delaying mammography to avoid problems with distortionis unwarranted, he said.

The diagnostic accuracy of mammog-raphy performed after FNA cameinto question more than a decade ago, he said, citing a Radiologyarticle (145:44, 1982).

The concern centered on the possibility that breast tissue distortionand hema-toma formation might cause benign lesions to appear malignanton mammog-raphy, leading to false diagnoses and unnecessary surgeries.A 10-day delay between FNA and imaging has been suggested (AmJ Surg 145:395, 1983).

"In the evolving era of rapid diagnostic service, it's notalways possible to perform imaging prior to FNA cytology,"Dr. Fenn said. "Delaying breast imaging may unnecessarilyheighten the anxiety of a woman who already is anxious about thediscovery of a lesion in her breast."

To reduce unnecessary waiting during this stressful period, theWelsh physicians perform imaging at the next available appointmentin the department of radiology, regardless of the time of fine-needleaspiration, he said.

Retrospective Review

The study patients were all referred to a specialized clinicalfor symptomatic breast disease. Dr. Fenn and his colleagues retrospectivelyreviewed patient records with respect to the timing and resultsof FNA cytology and breast imaging.

Most of the women (106) had imaging fewer than 5 days after aspiration.Thirty had imaging studies more than 10 days after aspiration.Imaging was performed with standard two-view mam-mography, ultrasound,or both.

Aside from the five patients with tissue distortion or hematomas,seven others had discordant results between FNA cytology and imaging.Three of the seven had malignant cytology and normal mammograms.Follow-up review of the images showed no tissue distortion, andsubsequent open biopsy confirmed the three malignancies.

Three patients had normal cytology and abnormal images, and allthree proved to have malignant disease. The seventh patient hada false-positive ultrasound with normal cytology, confirmed byopen biopsy.

Seventeen additional open biopsies were performed on lesions thatproved to be benign. Twelve of the 17 biopsies were done at thepatients' request, and the remaining five involved suspiciousbut inconclusive imaging studies (four ultrasound). None of the120 patients initially determined to have benign disease havedeveloped malignancies.

In the ideal setting, FNA cytology would always follow clinicalexam and imaging studies involving joint assessment by a surgeonand radiologist, Dr. Fenn commented in his presentation of thedata at the San Antonio Breast Cancer Symposium. As a practicalmatter, however, aspiration cytology will precede imaging in someinstances.

"The data suggest that the incidence of FNA damage seen onimaging, and consequent misdiagnosis, is lower than expected,"he said. "With the help of experienced breast radiologists,imaging after FNA can be performed safely without a mandatorydelay."