Phyllodes tumour among participants in screening mammography
FAs are among the most common breast neoplasms, being found in 9% of women in an autopsy series.2 Many FAs are first identified on screening mammograms. Mammographic screening is focused on diagnosing breast cancer, so masses with diagnostic features of FA may not be investigated. However, when the imaging features are not diagnostic of FA, additional testing is undertaken to exclude malignancy.
We have shown previously that the assessment of discrete masses found at screening is effective, with high rates of preoperative diagnosis.3 During the assessment of discrete masses, the differential of FA versus PT may be raised. When FA is diagnosed during screening of asymptomatic women, surgery is not recommended.4 However, even contemporary multi‐modality assessment, including clinical examination, mammography, ultrasound and needle biopsy, has limited success in distinguishing FA from PT,5 so that surgical excision and pathology are required for a definitive diagnosis. Most such lesions are ultimately found to be FAs and even if PT, most are of the benign subtype. In a prior review of 1083 discrete screen‐detected masses with indeterminate imaging features, including 623 new or enlarging lesions, we found only 3% of first round lesions and 13% of those with documented interval change were malignant.3 Screening programmes have a responsibility to limit surgery for non‐malignant lesions. Even though these diagnostic surgical biopsies are clinically appropriate, they add to the morbidity of screening.
In this study, we draw on the experience of a large, accredited, population‐based breast cancer screening programme to evaluate the diagnosis of PT in this context. We are unaware of similar prior reports. Our specific aims were to (i) present our experience with PT diagnosed among screening participants; (ii) identify discriminating features between FA and PT; (iii) assess the efficacy of breast cancer mammographic screening in identifying PT; and (iv) for women diagnosed with PT, determine appropriate breast cancer screening schedules.
This study was conducted with institutional review board approval for the purposes of monitoring and evaluation of service quality. The requirement for informed consent was waived.