Recent Developments in Diagnostic and Therapeutic Approaches to Breast Diseases
Daniel W. Visscher, M.D.
Carol Reynolds, M.D.
This specimen is from a 53 year old woman. What was the most likely mammographic
abnormality that prompted this core needle biopsy?
Radial scar is an uncommon but important lesion and a great deal of controversy has
surrounded radial scars in the breast. This lesion is characterized by a combination of epithelial
proliferation, stromal fibrosis and sclerosis resulting in a mass-like lesion. Radial scars can
clinically, mammographically, and histologically be mistaken for carcinoma. These stellate lesions are
usually only a few millimeters in size, but occasionally they are very complex, exceeding 1 cm.
Approximately less than 0.5% of core needle biopsies performed yield radial scar. The pathogenesis of
radial scars in the breast is still uncertain. However, there is no doubt that both in situ and invasive
carcinoma can occur in association with radial scars. Recent studies by Jacobs et al. and Sanders et al.
have shown that radial scars are a histologic risk factor for subsequent development of breast
carcinoma. Jacobs et al. demonstrated that the presence of radial scars almost doubles the risk of
breast cancer and this risk is further increased in women with larger or multiple radial scars. However,
radial scars are not in themselves thought to be premalignant.
Both the mammographic and histopathologic appearances of a radial scar overlap with tubular
carcinoma. Histologically, radial scars have a central sclerotic core composed of fibrosis and
elastosis. Entrapped ductules without atypia are easily found within the central core area. The finding
of a myoepithelial layer is a clue to the benign nature of this lesion. At the periphery of the radial
scar, there is a benign proliferation composed of adenosis, epithelial hyperplasia, cyst formation and
micropapillomas. In tubular carcinoma, a stellate configuration can also be found. However, the
diagnosis of tubular carcinoma is a microscopic one and is based on the presence of haphazard
proliferation of tubules with open lumens that are tear-drop shaped and lined by a single layer of
epithelial cells with apical snouts in about one third of cases. The neoplastic ducts in this lesion are
distributed in a background of desmoplastic stroma and not much in the way of benign proliferation is
seen. Cytologic atypia is minimal and a myoepithelial cell layer is absent.
The differential diagnosis includes sclerosing adenosis. At low power magnification, the entire
lesion maintains a lobular configuration with a well-defined periphery, unlike that seen in tubular
carcinoma. This lobular configuration is very helpful in differentiating this lesion from malignancy.
The size and shape of the tubular structures are quite variable. Many times the most sclerosed region is
in the center of the lesion with more dilated ductules around the periphery. However, there are cases of
irregular sclerosing adenosis where the tubules are haphazardly arranged and appear pseudoinfiltrative.
Apocrine metaplasia is occasionally seen involving sclerosing adenosis; these areas often raise concern
for carcinoma. The architecture of sclerosing adenosis may not be as apparent, making the diagnosis
sometimes quite difficult on core needle biopsy. The double cell lining with myoepithelial cells and
lack of atypia can be very helpful to confirm the benign process.
Few studies have correlated the findings in an open biopsy when a radial scar is diagnosed on core
needle biopsy. Jackman et al. carried out a study to determine the rate of false-negative findings and
histologic underestimates in stereotactic biopsy of nonpalpable lesions. Five radial scars diagnosed in
core needle biopsy were included in this study. Two of five radial scars demonstrated carcinoma at open
biopsy (1 DCIS, 1 invasive carcinoma). Based on this finding, they believe that radial scars should be
categorized as high-risk lesions and require excision. Philpotts et al. found no carcinomas at excision
of core needle biopsy detected radial scars; however, there was a high rate of atypia at excision (50%),
with four of eight lesions showing atypical ductal hyperplasia.
Recently, Brenner et al. evaluated the outcome of cases where radial scar was diagnosed by core
needle biopsy. One hundred fifty-seven lesions constituted their study group, with 102 having surgical
excision and 55 with mammographic surveillance. They found carcinoma in 28% (8/29) of lesions with
associated atypia (not included in table below) and 4% (5/128) of lesions without associated atypia.
Cawson et al. reported their experience with core needle biopsy in sampling radial scars. Fifty-four
lesions diagnosed as radial scar went to open biopsy and 4 were found to reveal DCIS associated with
radial scar; however, all four of these lesions were diagnosed as DCIS or atypical ducal hyperplasia on
core needle biopsy. This data adds confusion about management of patients diagnosed with radial scar on
core needle biopsy since these patients would be referred to open biopsy without the co-existent radial
Summary of Surgical Biopsy Findings in Women with Radial Scar at Core Needle Biopsy*
|Core Biopsy ||Surgical Excisional Biopsy|
|Benign ||Atypical ||DCIS ||Inv CA|
|233 ||184 (79%) ||37 (16%) ||11 (4.5%) ||1 (0.5%)|
*Jackman (1999), Philpotts (2000), Kirwan (2000), Brenner (2002), Cawson (2003)
Still there is insufficient data on this entity to know how to appropriately manage a patient when
the diagnosis of radial scar is rendered at core needle biopsy. Many clinicians feel that for this
reason, all radial scars should prompt excision. Others believe that if the mammographic abnormality has
the appearance of a radial scar, needle localization and open surgical biopsy is a more suitable approach
than core needle biopsy. Larger studies with both surgical and mammographic follow up are very much
needed to resolve this issue .
- Alleva DQ, Smetherman DH, Garr, GH, Cederbom GJ. Radial scar of the breast: Radiologic pathologic correlation in 22 cases. Radiographics 1999; 19:S27-S35.
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- Cawson JN, Malara f, Kavanagh A, Hill P, Balasubramanium G, Henderson M. Fourteen-gauge needle core biopsy of mammographically evident radial scars. Is excision necessary? Cancer 2003; 97:345-351.
- Elvecrog EL, Lechner MC, Nelson MT. Nonpalpable breast lesions: Correlation of stereotaxic large core needle biopsy and surgical biopsy results. Radiology 1993; 188:453-455.
- Jacobs TW, Byrne C, Colditz G, Connolly JL, Schnitt SJ. Radial scars in benign breast biopsy specimens and the risk of breast cancer. NEJM 1999; 340:430-436.
- Jackman RJ, Nowels KW, Rodriguez-Soto J, Marzon FA, Finkelstein SI, Shepard MJ. Stereotactic automated, large-core needle biopsy of nonpalpable lesions: False negative and histologic underestimation rates after long-term follow-up. Radiology 1999; 210:799-805.
- Liberman L. Clinical management issues in percutaneous core breast biopsy. Radiol Clin North Am 2000; 38:791-807.
- Philpotts LE, Shaheen NA, Jain KS , Carter D, Lee CH. Uncommon high risk lesions of the breast diagnosed at stereotactic core needle biopsy: Clinical importance. Radiology 2000; 216:831-783.
- Reynolds HE. Core needle biopsy of challenging benign breast conditions: A comprehensive literature review. AJR 2000; 174:1245-1250.
- Sanders ME, Dupont WD, Schuyler PA, Simpson JF, Page DL. Interdependence of radial scar and proliferative disease with respect to invasive breast cancer risk in benign breast biopsies. Modern Pathology 2002; 15:50A.