Preoperative localization of breast lesions: Tailored techniques and potential pitfalls

Preoperative Localization of Breast Lesions: Tailored Techniques and Potential Pitfalls By Kathryn Evers and Rosalind H. Troupin

WIDESPREAD implementation of T HEscreening mammography has resulted in the detection of a spectrum of lesions, some of which merit surgical excision rather than short interval mammographic follow-up or needle biopsy. In order to ensure that appropriate tissue is excised and sampled, a coordinated effort among radiologist, surgeon, and pathologist is required. Within the United States, the positive yield of carcinoma in needle-localized biopsy specimens is currently in the 20% to 30% range, 1-6 reflecting a deliberately determined threshold of suspicion set by the radiologist? Experience in Europe cites a higher percentage of positive biopsies] based on combinations of higher thresholds, well-established screening programs, and a greater willingness to implement short interval follow-ups. DEVELOPMENT OF LOCALIZATION TECHNIQUES AND DEVICES

Methods for performing preoperative localization procedures for nonpalpable breast abnormalities have developed over the past 20 years. Initially, mammographers described and diagrammed lesions for the surgeons, based on distances measured directly from mammographic films and using the nipple as a reference point. Because of gross rearrangements in breast structures between the upright, compressed positioning of mammography and the recumbent position during surgery, large biopsy specimens were required to ensure removal of the abnormalities. In 1972, the "blue dot" technique was described) Under mammographic guidance, blue dye was injected at the site of the lesion, and a track of dye was injected as the needle was From the University of Pennsylvania Medical Center; the University of Pennsylvania School of Medicine; and the Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA. Address reprint requests to Kathryn Evers, MD, Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104. Copyright 9 1993 by 14dB. Saunders Company 0037-198X/93/2803-000755.00/0 242

withdrawn. Additionally, if iodinated contrast material was mixed with the dye, radiographic verification of the placement could also be obtained before the patient left for the operating room. One disadvantage of this method is that rapid diffusion of the dye occurs and biopsy cannot be delayed after injection. In addition, it has recently emerged that methylene blue, one of the dyes commonly used for this procedure, may interfere with estrogen-receptor assays. 9,1~ As localization methods evolved, placement of simple hypodermic needles came to be used. u Guided by baseline films and measurements, a needle of proper length was inserted to its hub, and its relationship to the lesion was verified by cephalocaudad and mediolateral mammographic filming. The needle was then carefully secured to the skin by tape. This technique was used successfully in many centers, with only rare instances of needle dislodgment by experienced surgeons.ll In 1976, Frank 12described a 25-gauge needle, preloaded with a wire and protruding hook, that permitted removal of the needle and retention of the wire hook after verification of positioning. Shortly thereafter, a contained springloaded hook-wire system was described by Kopans and Deluca. 13 Advantages of this system were that the wire and hook were completely contained within the needle, a skin nick was not required, and the position of the needle tip could be readjusted before the hook was advanced and engaged. The original and many subsequent variations on this Kopans hook wire device are used widely today. When using these devices, repositioning or removal of the hook wire after it is engaged is not a recommended option. For this reason, and because of instances of inadvertent surgical transection of wires, Homer in 198514,15 developed a device in which a 20-gauge needle houses a strong, curvedend retractable nitinol alloy wire. The engaged J wire can be withdrawn into the needle for repositioning and can subsequently be readvanced. After removal of the needle, the wire is stabilized at the skin with a tiny clamp. Although the initial description of this device Seminars in Roentgenology, Vol XXVIII, No 3 (July), 1993: pp 242-251

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proposed removal of the needle after the wire was positioned, a later revision recommended retention of the needle to provide a more easily palpable guide for the surgeon. 16 Additional types of hook-wire devices are commercially available, including braided coaxial wires and hook wires with barbed tips. 17 Successful localization procedures can be performed using a w of the commercially available systems, and the choice of appropriate system will depend on the mutual preferences of the radiologist and surgeon involved in localization procedures. PREOPERATIVE FILM REVIEW, PROBLEM SOLVING, AND COMMUNICATION

Often, the radiologist who is scheduled to perform the preoperative localization is not the same one who originally recommended that biopsy be performed. Although discordant opinions are inevitable, mechanisms for resolution of differences must focus on avoiding the anxiety, expense, and inconvenience of a cancellation of biopsy plans on the morning of scheduled surgery. Films should be reviewed as early as possible, preferably several days before, to allow for possible re-evaluation by problem solving and/or old film review. In a recent review of 603 patients scheduled for preoperative needle localization,18 8.8% (53 patients) were cancelled on the day of the procedure. The reasons for cancellation of cases included failure to have confirmed a three-dimensional lesion, failure to recognize calcification as intradermal, an interval decrease in the size of a nodule, and demonstration of stability when compared with a belatedly received old examination. Needle localizations should be performed only if a true, three-dimensional abnormality exists. Experienced mammographers are reminded daily that "pseudo-masses" and apparent stellate distortions may easily be created in the breast due to overlapping fibroglandular tissue. Additional tailored projections and spot compression films are used to corroborate or exclude the presence of a true lesion. 6,19Uncommonly, adjunctive imaging with ultrasonography2~ or computed tomography22may be used. Intradermal calcifications are invariably benign and should not be removed. 23 They typically have rounded or polygonal shapes with

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lucent centers and are generally positioned toward the periphery of the breast. However, occasionally their shapes may be atypical, and they may be projected deeply into the breast images, leading to confusion with true intramammary calcifications. Established techniques to document intradermal location rely on bringing skin calcifications into tangent or on demonstrating their persistent relationship to an overlying metallic skin dot. 24By awareness of the possibility that a cluster of calcifications may be intraderreal, and by applying these confirmatory techniques, ill-fated attempts at surgical excision can be avoided. Communication between the radiologist and surgeon is essential before performance of the needle localization in order to define the goal of the biopsy procedure. 25 For instance, in cases with a relatively large area of calcification, localization can be performed either for representative sampling or to attempt total removal. If only sampling is desired, a single needle accurately placed in the most suspicious portion of calcifications is needed (Fig 1). If complete removal of the calcifications is contemplated, it may be more helpful to insert two hook wires to delimit the boundaries of calcifications (Fig 2). Similarly, preoperative discussion should occur in the instance of a mammographic "nodule,"

Fig 1. Sampling of calcifications. A hook wire has been placed in the most suspicious portion of an extensive calcification (arrows) for sampling.

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LOCALIZATION PROCEDURE

Fig 2. Complete removal of calcifications. Two hook wires delimit the boundaries of a zone of calcification (arrows) to ensure complete removal,

which fails some of the sonographic criteria of a simple cyst. Localization should begin with a serious attempt at aspiration, with the sterile hook wire set aside. If no fluid is aspirated, the needle would then be afterloaded and the hook wire engaged for surgical biopsy. 5

PREPARATION OF THE PATIENT

Before beginning the procedure, the purpose, technique, and complications are explained to the patient and informed consent is obtained. Patients at our institution do not receive premedication before needle localization because we prefer an alert, cooperative patient whose anxiety is managed by sympathetic reassurance and distractive small talk. The patient should not view the approaching or protruding needle during the procedure. Attempts should be made to keep the patient's head turned and gaze directed elsewhere. Vasovagal reactions do occur in a small but significant percentage of patients, 26 and it is important never to leave a patient alone in the x-ray room after insertion of a needle. The radiologist should be prepared to treat a vasovagal reaction when necessary. A stretcher should be readily available, either within the mammographic room or immediately outside the door.

After the need for needle localization has been established, the management goal of the procedure acknowledged, and patient consent obtained, the needle localization procedure can be performed. Lesions may be approached from directions either parallel or perpendicular to the chest wall. Although exclusive use of one or the other of these approaches has been advocated, we prefer to tailor the examination, selecting an entry point closest to the lesion in order to minimize the amount of breast tissue traversed. However, other considerations such as strong preferences by the surgeon or the orientation of a ductal array of calcifications are taken into account.

ParallelApproach Through a Grid Most dedicated mammographic machines are equipped with a compression plate through which localization procedures can be performed. This may be a multifenestrated plate 27 or a rectangular cutout, marked with alphanumeric coordinates. 28 This compression plate can be used for any approach parallel to the chest wall, whether superior, inferior, lateral, or medial. By reference to the current films, the plate is positioned with the open or fenestrated portion overlying the lesion (Fig 3A). A film is exposed, the lesion is located on the film, and appropriate coordinates are identified. The skin is either marked or a cross-hair light localizer is appropriately adjusted. The skin overlying the lesion is then cleansed, and a needle of appropriate length, as determined from the diagnostic mammogram, is inserted to its hub. During the insertion, the light localizer on the mammographic unit can be used to ensure positioning of the needle perpendicular to the compression plate. 29 If the needle hub shadow is superimposed on the shaft and skin puncture site, the entry is perfectly perpendicular to the skin. Tilted shadows will be cast if the needle is angulated in any direction, and appropriate adjustment in direction can be made. A film is usually obtained in that position through the open compression plate (Fig 3B). It may be set aside or developed, depending on the radiolo-

PREOPERATIVE NEEDLE LOCALIZATION

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Fig 3,

Needle localization using an alpha-numeric grid. (A)

The nodule to be localized (arrow) is identified on this craniocaudad film w i t h the localization plate. A clinical decision was made to remove this recurrent cyst, and the localization plan was to avoid puncturing and deflating it. (B) The needle was deliberately placed directly behind the lesion (arrow) and is observed with the hub superimposed on the shaft. (C) A spot compression mediolateral film demonstrates needle depth and the relationship of the needle to the nodule (arrow). Adjustments in needle depth as well as engagement of hook wire should be performed with the patient held in compression. Final films in the craniocaudad (D) and mediolateral (E) projections, demonstrating the relationship of the hook wire to the nodule (arrow). Metallic dot is placed at the skin entry site.

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gist's confidence that there has been no patient motion after the scout film and that needle position is good in two dimensions. While the breast and needle are supported, the mammography unit is rotated 90~ and an orthogonal film is obtained (Fig 3C). By using the smaller spot compression plate rather than the full-sized compression plate, there is better accessibility to the puncture site. 5,2s If the wire is engaged while the breast remains in compression, the depth of needle insertion can be ensured. If the breast is removed from compression and allowed to merely rest on the mammographic platform, the ability to control the depth of the needle position is lost, especially if the needle approach has been from a superior direction. Once the films are viewed, the needle depth can be adjusted, after which the hook wire is engaged and the needle removed. Final films are taken in both the craniocaudad and mediolateral positions (Figs 3D and 3E). Because the surgeon cannot distinguish superimposed wire from intramammary wire on the films, a metallic skin dot is placed at the entry site. If a J-wire system is used with a needle that is not removed, the final filming sequence may be eliminated.

Anterior Approach There are circumstances in which an anterior approach is acceptable or even preferable. If the lesion to be localized is relatively central or

EVERS AND TROUPIN

is in the anterior half of a nonflabby breast, the localization may be performed via an anterior approach, perpendicular to the chest wall. For this approach, guidance for the insertion point is provided by scout films with a metal dot positioned by reference to measurements from the original films. Although the needle is inserted while the patient's breast is resting on the mammographic platform, the radiologist compresses the breast mediolaterally to simulate relationships that had existed during the original mediolateral mammographic projection. Once the needle is inserted, films are obtained in craniocaudad and mediolateral projections (Fig 4). If needle position needs to be readjusted, this is accomplished, and the hook wire is engaged. Final films are obtained after placement of the skin marker. There are three potential advantages to the judicious use of the anterior approach: (1) Well-compressed craniocaudad and mediolateral films can be easily made and can facilitate orientation in the operating room; (2) This positioning is highly compatible with a periareolar surgical approach following the wire and diminishes the possibility of transection; (3) With a slightly angled anterior approach, the wire can be aligned to facilitate removal of a linear array of calcifications that are following a diverging duct system (Fig 4). In this instance, in order to completely excise those calcifications

Fig 4. Needle localization using an anterior approach. Craniocaudad (A) and mediolateral (B) films show pleomorphic calcifications in a ductal linear array (arrows), localized using an anterior approach. Pathology showed intraductal carcinoma.

PREOPERATIVE NEEDLE LOCALIZATION

using an approach paralleling the chest wall, a pair of wires is needed. The same principle is true for other abnormalities where the spatial distribution of the lesion is anteroposterior. Potential disadvantages cited for the use of an anterior (perpendicular) approach are a risk of pneumothorax and a more time consuming procedure. 2s Although the possibilities of pneumothorax or of hooking the pectoralis muscle theoretically exist, these are extremely rare occurrences. 3~ A case of pneumothorax caused by a needle localization procedure has never occurred at this institution. Accurate anterior needle placement is an acquired skill that requires the ability to mentally visualize the needle tip three dimensionally within the breast. With guided supervision, the skill is readily learned and needle readjustments become very infrequent. Regardless of the approach used, at the end of the procedure the wire is bent at the skin surface and taped to the skin, preventing deep migration. A dressing is then placed over the wire, and the patient is assisted onto a stretcher. The patient is cautioned to limit large motions of that arm. The final set of films is prominently labeled with a wax crayon for orientation in the operating room. The marked films, a "stat" reading card, and a chart note describing the relationship of the lesion to the wire accompany the patient to the operating room. COMPLICATIONS

Complications of needle localization procedures do occur, the commonest being vasovagal reactions including syncope. The incidence of this group of reactions was 8% as reported in one series. 26 Comparison with other experiences would be difficult because a spectrum of vasovagal symptoms would begin at mild, transitory, light-headedness. Unless questioned, the patient might not spontaneously mention this, and one could argue that conversation which distracts rather than focuses on these symptoms, would be in the patient's best interests. Ecchymoses or hematomas may follow insertion of the needle into the breast, 3~ resulting from vessel puncture (Fig 5). Although these most commonly occur in the region of the target lesion, an occasional more remote one may occur. Remote ecchymoses or hematomas occur

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when a grid system is used and the inserted needle extends past the lesion to the far side of the breast while the breast is compressed to a narrow depth. With orthogonal recompression and the needle hub at the skin, the needle tip retracts far proximal from its former position and the remote hematoma appears paradoxical. Although pneumothorax is probably the most serious potential complication, it is an extremely rare event, 31,3~ as is migration of wires into remote locations of the body. 33 An uncommon but not extraordinarily rare event is intramammary displacement of the hook from its intended location (Fig 6). Distal migration of the wire within the breast can occur as repositioning and recompression result in more of the wire being enveloped by the breast. 31-35Respiratory and muscular activity during transportation, prolonged delays, and transfer from stretcher to operating table may account for distal wire displacements, particularly with posterior lesions. These complications are entirely preventable by bending and securely taping the wire to the skin, or in the case of the curved-end J wires, by using the skin clamp provided. In patients with fatty breasts, the wire may retract proximally toward the skin surface because of limited stroma for hook wire anchorage. 28 This problem can be prevented by placing the hook somewhat deeper to the lesion and by alerting the surgeon to avoid any traction on the wire. Broken or transected wires are a problem that will have a variable incidence, depending on the surgical personnel involved. If an institution is experiencing transections, consideration should certainly be given to conversion to a more resistant system. If the thinner hook wire systems are used, transection may result in a nonpalpable, retained distal fragment. 2,36Transected hook wire fragments may remain in position within the breast indefinitely. However, the potential theoretically remains for distant migration and some workers recommend their removal. Excision of these fragments can be guided by preoperative needle localization. 3v Failure to remove the mammographically suspicious lesion will occasionally occur. 38,39 Homer has reported an incidence of 5% 4o and includes this complication during the informed consent discussion with each patient.

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Fig 5.

Hematoma developing during needle localization.

(A) Mediolateral film following hook-wire placement, demonstrating a hematoma (arrows) overlying the site of needle placement. (B) Compressed craniocaudad view in the same patient shows the remote location of the hematoma (arrow) from the lesion and the wire. Needle insertion to the hub had been performed while the breast was in mediolateral compression and much narrower. With cephalocaudad compression, the breast widens and the needle tip retracts from the traumatized area. Note that the thickened portion of the wire has been placed adjacent to the nodule.

PREOPERATIVE NEEDLE LOCALIZATION

Fig 6. Displaced wire. Two foci of calcification (arrows) were localized by the two more posterior wires, which were both originally in proximity to the calcifications. On arrival in the operating room, only one wire was visible protruding from the breast. The patient was returned to the mammography area, where distal migration of the wire was documented and a new hook wire was placed to localize the calcifications. All of the wires as well as calcifications were successfully removed.

SPECIMEN MANAGEMENT AND TISSUE CORRELATION

Surgical specimens, excised by needle localization guidance, should be radiographed for confirmation of the presence of the relevant lesion. 41 This is an absolute requirement when localization is performed for calcification, architectural distortion, or poorly defined neodensity. If a focal nodule, corresponding in size and shape to the mammographic lesion, is visible and palpable in the specimen by the surgeon,

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radiography may be omitted. In working with specimen radiographs, if the wire is in very close proximity to the lesion, especially in a small specimen, this should provide satisfactory guidance for the pathologist. If proximity is less optimal, additional measures may be needed to ensure that the appropriate area is intensively sampled. Traditionally, an in vitro needle has been inserted into the specimen to further pinpoint the area of interest. Handling surgical specimens that contain protruding wires and needle tips pose risks due to human immunodeficiency virus/hepatitis safety precautions, and other alternatives are being explored. Injection or surface placement of dye has been suggested as a method of marking the specimen, remembering that after gross description, the surfaces of the specimen will be inked to identify surgical margins. In addition, some of the available dyes may interfere with estrogen receptor assays, and the surgical pathologist should be involved in the decision. Placement of a nonmetallic suture is another possibility but should be done with awareness that surgeons use marker sutures to inform the pathologist of specimen orientation in the event of the need for re-excision. An alternative approach involves specimen cassettes such as the Pathfinders or the Levinsohn systems. 42,43 These consist of alpha-numeric perforated plates for specimen radiography. The specimen goes to pathology while still clamped in the device and accompanied by the marked, annotated radiographs. This permits the pathologist to mark the focus before gross sectioning. The depiction of calcifications on specimen radiographs is almost invariably superior to the in vivo mammographic images. Confirmation of stellate distortions and noncalcified nodules may be challenging if the lesion orientation, stromal support, or relationship to adjacent fat have changed. The routine use of compression during specimen radiography has obviated earlier problems caused by irregularities on the surface of the specimen?4 However, in some cases, visualization of a nodule may be difficult and may be assisted by two-view orthogonal radiography.45 Determining whether a lesion, calcified or otherwise, extends to the edge of the specimen is obviously not straightforward on a

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single view. An abnormality that appears to be centrally located within the specimen may actually be on the superior or inferior surface. Accuracy may be improved by an additional projection, although a strictly orthogonal view may be difficult to achieve with a floppy piece of tissue. The presence or absence of the hook wire should be mentioned within the report to document removal of the wire. Report of the specimen radiograph is then called to the operating room where in most cases, surgical closure awaits this telephoned report. There are at least two reasons to perform careful correlation of mammographic findings with the gross and microscopic examinations. 41 The most important reason, of course, is to be absolutely certain that the mammographically suspicious focus is thoroughly evaluated for carcinoma. However, additionally, if the calcifications or nodules that prompted biopsy prove to be benign, but there is carcinoma elsewhere in the specimen, this "true positive" should have a very different impact on the radiologists' learning curve. Stein and Karlan have described a 7% overall failure rate in correlations between pathology reports and excised mammographic calcifications. 46 Calcifications were not documented by pathology for several resolvable

reasons that emerged on review. There were instances not mentioned in the report where slide review disclosed obvious benign calcification. In other instances, polarized light was necessary to show calcium oxalate crystals. 47 There were instances of sampling error where calcium remained in the paraffin blocks and never reached the slides. 48 However, in 3 of the 12 cases of "lost" calcifications, the calcium could not be identified despite review of the slides and blocks. This suggests that a processing problem such as calcium dissolution by acid fixatives or particles shattered out of tissue sections might have been involved. Calcification recorded in pathology reports in instances of noncalcified mammographic lesions reflects particle size smaller than the resolution of the mammographic systems. 49 SUMMARY

Preoperative needle localization procedures can be performed using a variety of devices and tailored approaches. Success in these endeavors can be optimized through communication and coordination among the radiologist, surgeon, and pathologist. Meticulous attention to performance and radiological-pathological correlation are required to ensure the best possible results.

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8. Horns JW, Arndt RD: Percutaneous spot localization of nonpalpable breast lesions. AJR 127:253-256, 1976 9. Hirsch JI, Banks WL, Sullivan JS, et al: Effect of methylene blue on estrogen-receptor activity. Radiology 171:105-107, 1989 10. Hirsch JI, Banks WL, Sullivan JS, et al: Noninterference of isosulfan blue on estrogen-receptor activity. Radiology 171:109-110, 1989 11. Libshitz HI, Feig SA, Fetouh S: Needle localization of nonpalpable breast lesions. Radiology 121:557-560, 1976 12. Frank HA, Hall FM, Steer ML: Preoperative localization of nonpalpable breast lesions demonstrated by mammography. N Engl J Med 195:259-260, 1976 13. Kopans DB, DeLuca S: A modified needle-hookwire technique to simplify preoperative localization of occult breast lesions. Radiology 134:781, 1980 14. Homer MJ, Pile-Spellman ER: Needle localization of occult breast lesions with a curved-end retractable wire: Technique and pitfalls. Radiology 161:547-548, 1986 15. Homer MJ: Nonpalpable breast lesion localization using a curved-end retractable wire. Radiology 157:259-260, 1985 16. Homer MJ: Localization of nonpalpable breast le-

PREOPERATIVE NEEDLE LOCALIZATION

sions with curved-end, retractable wire: Leaving the needle in vivo. AJR 151:919-920, 1988 17. Urrutia EJ, Hawkins MC, Steinbach BG, et al: Retractable-barb needle for breast lesion localization: Use in 60 cases. Radiology 169:845-847, 1988 18. Meyer JE, Sonnenfeld MR, Greenes RA, et al: Cancellation of preoperative breast localization procedures: Analysis of 53 cases. Radiology 169:629-630, 1988 19. Swann CA, Kopans DB, McCarthy KA, et al: Localization of occult breast lesions: Practical solutions to problems of triangulation. Radiology 163:577-579, 1987 20. Kopans DB, Meyer JE, Lindfors KK, et al: Breast sonography to guide cyst aspiration and wire localization of occult solid lesions. AJR 143:489-492, 1984 21. Laing FC, Jeffrey RB, Minagi H: Ultrasound localization of occult breast lesions. Radiology 151:795-796, 1984 22. Levinsohn EM, Numann PA, Groskin SA: Computed tomography in preoperative localization of occult breast cancer. Breast Dis 1:77-81, 1988 23. Kopans DB, Meyer JE, Homer MJ, et al: Dermal deposits mistaken for breast calcifications. Radiology 149: 592-594, 1983 24. Berkowitz JE, Gatewood OMB, Donovan GB, et al: Dermal breast calcifications: Localization with templateguided placement of skin marker. Radiology 163:282, 1987 25. Meyer JE, Kopans DB: Preoperative roentgenographically guided percutaneous localization of occult breast lesions. Arch Surg 117:65-68, 1982 26. Helvie MA, Ikeda DM, Adler DD: Localization and needle aspiration of breast lesions: Complications in 370 cases. AJR 157:711-714, 1991 27. Goldberg RP, Hall FM, Simon M: Preoperative localization of nonpalpable breast lesions using a wire marker and perforated mammographic grid. Radiology 146:833-835, 1983 28. Kopans DB, Lindfors K, McCarthy KA: Spring hookwire breast lesion localizer: Use with rigid-compression mammographic systems. Radiology 157:537-538, 1985 29. Caldarelli J, Cronan JJ, Scola FH, et al: Shadow technique: A method for accurate and quick mammographic needle localization. Breast Dis 1:29-31, 1987 30. Gisvold J J, Martin JK: Prebiopsy localization of nonpalpable breast lesions. AJR 143:477-481, 1984 31. Davis PS, Wechsler RJ, Feig SA, et al: Migration of a breast localization wire. AJR 150:787-788, 1988 32. Bristol JB, Jones PA: Transgression of localizing wire into the pleural cavity prior to mammography. Br J Radiol 54:139-140, 1981

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33. Owen AWMC, Kumar EN: Migration of localizing wires used in guided biopsy of the breast. Clin Radiol 43:251, 1991 34. Meyer JE, Sonnenfeld MR, Greenes RA, et al: Preoperative localization of clinically occult breast lesions: Experience at a referral hospital. Radiology 169:627-628, 1988 35. Homer MJ: Localization of nonpalpable breast lesions: Technical aspects and analysis of 80 cases. A JR 140:807-811, 1983 36. Homer MJ: Transection of the localization hooked wire during breast biopsy. AJR 141:92%930, 1983 37. Mitnick JS, Vazquez MF, Harris MN, et al: Localization of transected wire. AIR 156:866, 1991 38. Stein MA, Karlan M: Immediate postoperative mammogram for failed surgical excision of breast lesions. Radiology 178:159-162, 1991 39. Bigongiari LR, Fidler W, Skerker LB, et al: Percutaneous needle localisation of breast lesions prior to biopsy: Analysis of failures. Clin Radio128:419-425, 1977 40. Homer MJ, Smith TJ, Safaii H: Prebiopsy needle localization. Radiol Clin North Am 30:139-153, 1992 41. Stomper PC, Davis SP, Sonnenfeld MR, et al: Efficacy of specimen radiography of clinically occult noncalcifled breast lesions. AJR 151:43-47, 1988 42. Lindfors KK, Lott SA, Alberhasky MT: A new device for evaluation of biopsy specimens of occult breast lesions. AIR 154:261-263, 1990 43. Levinsohn EM: Device for facilitating lesion localization in breast biopsies. Radiology 181:603-604, 1991 44. Chilcote WA, Davis GA, Suchy P, et al: Breast specimen radiography: Evaluation of a compression device. Radiology 168:425-427, 1988 45. Rebner M, Pennes DR, Baker DE, et al: Two-view specimen radiography in surgical biopsy of nonpalpable breast masses. AJR 149:283-285, 1987 46. Stein MA, Karlan MS: Calcifications in breast biopsy specimens: Discrepancies in radiologic-pathologic identification. Radiology 179:111-114, 1991 47. Tornos C, Silva E, El-Naggar A, et al: Calcium oxalate crystals in breast biopsies. Am J Surg Pathol 14:961-968, 1990 48. Rebner M, Helvie MA, Pennes DR, et al: Paraffin tissue block radiography: Adjunct to breast specimen radiography. Radiology 173:695-696, 1989 49. Stomper PC, Davis SP, Weidner N, et al: Clinically occult, noncalcified breast cancer: Serial radiologic-pathologic correlation in 27 cases. Radiology 169:621-626, 1988