Abstract and Introduction
Objective. The purpose of this study was to evaluate the feasibility of short-term follow-up of palpable masses that have benign imaging features.
Materials and methods. The cases of all women with round, oval, or lobular palpable masses with circumscribed margins and homogeneous ultrasound echotexture for which short-term follow-up was recommended from July 1997 through December 2003 were retrospectively identified. Evaluation was by ultrasound and/or mammography and focused clinical examination. Outcome was assessed with imaging or clinical follow-up lasting at least 12 months. The cancer incidence for palpable lesions was compared with that for nonpalpable lesions recommended for short-term follow-up.
Results. In 379 women, 443 palpable masses with benign features for which short-term follow-up was recommended were identified. Outcome data were available on 375 masses in 320 women. Lesions were evaluated with mammography and ultrasound (n = 186) or ultrasound alone (n = 189). Masses were typically identified only with ultrasound (n = 258, 68.8%); were oval (n = 275, 73.3%), of equal density to normal breast tissue on mammograms (n = 95 on 117 mammograms, 81.2%), and hypoechoic (n = 336 in 372 ultrasound examinations, 90.3%); and were prospectively believed to be fibroadenoma (n = 304, 81.1%). Eighty-five lesions (22.7%) were biopsied soon after evaluation, and one 1.5-mm ductal carcinoma in situ was diagnosed. At follow-up (mean, 2.7 years), 26 lesions (6.9%) had grown. Twenty-four of the 26 lesions were biopsied, and no cancer was diagnosed. The overall cancer prevalence was similar for palpable (0.3%) and nonpalpable (1.6%) masses. The cost of short-term follow-up was less than that of biopsy.
Conclusion. Short-term follow-up is a reasonable alternative to biopsy of palpable breast lesions with benign imaging features, particularly for young women with probable fibroadenoma.
The indications for short-term follow-up of nonpalpable breast lesions are well established. BI-RADS calls for initial short-term follow-up (BI-RADS assessment category 3, probably benign finding) of solid well-defined masses, focal asymmetries, and grouped punctate calcifications on a baseline mammogram or when previous mammograms cannot be obtained. In the early 1990s, Sickles and Varas et al. found short-term follow-up of these lesions a reasonable alternative to biopsy because the incidence of breast cancer was less than 2% and cancer subsequently diagnosed was at an early stage. Cancer incidence later was reported to be independent of lesion size and patient age.
Although Sickles did not explicitly state that women with palpable findings were excluded from the study, later clarification confirmed that they had been. Of note, the third edition of BI-RADS, published in 1998, did not address whether in the assignment of assessment category 3, probably benign finding, lesion management would differ depending on the palpable or nonpalpable nature of the lesion. Regarding the use of BI-RADS category 3, the third edition stated, "At the present time, most approaches are intuitive. These will likely undergo future modification as more data accrue as to the validity of an approach, the interval required, and the type of findings that should be followed." It was not until publication of the fourth edition of BI-RADS in 2003 that a distinction was made for management of palpable lesions. The fourth edition of BI-RADS states that "all published studies exclude palpable lesions, so the use of a probably benign assessment for a palpable lesion is not supported by scientific data."
The criteria for short-term follow-up of masses with benign features at ultrasound examination are not as well validated as they are for such masses found at mammography. Using sonographic criteria, Stavros et al. described benign and malignant features of 750 solid masses. Lesions classified prospectively as benign had a cancer incidence of 0.5%. Of interest, 278 women (37%) in the total study sample of 750 in that study had palpable findings. The study outcomes were similar for palpable and nonpalpable lesions. More recently, Graf et al. found a 0.2% incidence of cancer (95% CI, 0.0–1.23%) among 445 solid nonpalpable masses with benign features detected with ultrasound that had been obscured or partly obscured at mammography. The ultrasound criteria for inclusion in the study were oval or lobular shape, circumscribed margins, parallel orientation, isoechoic or mildly hypoechoic echotexture, and absence of shadowing.
Subsequent studies have well documented the outcome of short-term follow-up of nonpalpable lesions with benign features on baseline images,[9,10] but little information exists on palpable lesions. In 2004, Graf et al. described a series of 157 palpable noncalcified solid masses with benign imaging features that were observed with short-term follow-up rather than biopsied. No cancer was diagnosed among the palpable lesions in that study. All patients in the study underwent mammography with or without ultrasound and were observed for at least 2 years (mean, 4.1 years).
Owing to the findings of early studies of short-term follow-up as an alternative to biopsy, in the mid-1990s all faculty members at our institution began recommending short-term follow-up of masses that had benign features at imaging but did not have ultrasound features of simple cyst. Both palpable and nonpalpable lesions were included. In this study, we retrospectively evaluated our experience with short-term follow-up of 375 palpable lesions with benign imaging features in 320 consecutively registered women.
Am J Roentgenol. 2009;193(6):1723-1730. © 2009 American Roentgen Ray Society
Cite this: Short-term Follow-up of Palpable Breast Lesions with Benign Imaging Features: Evaluation of 375 Lesions in 320 Women - Medscape - Dec 01, 2009.