A utility of ductography and fiberoptic ductoscopy for patients with nipple discharge

Breast ductography: to do or not to do? A pictorial essay

Nipple discharge is a frequent breast disease clinical presentation. Although most cases of nipple discharge are physiologic, pathologic nipple discharge is not uncommon. Eight to 15% of pathological nipple discharge is associated with malignancy, requiring investigation. Some specialists believe that ductography is a challenging procedure that is better to be substituted by other methods, such as MRI. However, an experienced physician can perform ductography quickly and easily and still play an essential role in some clinical scenarios. Conventional imaging, such as mammography and sonography, commonly fails to detect the underlying causes of pathological nipple discharge. MRI has limitations of low specificity, cost, lengthy exam duration, accessibility, and patient factors such as claustrophobia. In addition, we can make a specific diagnosis and appropriate treatment by coupling ductography with other methods, such as ultrasound-guided or stereotactic biopsy. This study aims to present the ductography technique, possible findings, and the clinical settings where ductography is useful.Critical relevance statement Although ductography is currently less used in breast imaging, it still plays an essential role in some clinical scenarios. These clinical scenarios include pathological nipple discharge with negative conventional imaging, contraindicated MRI, unavailable MRI, unremarkable MRI results, and multiple MRI findings.Key points• Conventional imaging commonly fails to detect the underlying causes of pathological nipple discharge.• MRI in the setting of nipple discharge has some limitations.• Ductography still plays an essential role in some clinical scenarios.• Coupling ductography with other methods helps make a specific diagnosis.

Diagnostic Accuracy of Nipple Discharge Fluid Cytology: A Meta-Analysis and Systematic Review of the Literature

Background

Nipple discharge is the third most frequent complaint of women attending rapid diagnostic breast clinics. Nipple smear cytology remains the single most used diagnostic method for investigating fluid content. This study aimed to conduct a systematic review and meta-analysis of the diagnostic accuracy of nipple discharge fluid assessment.

Methods

The study incorporated searches for studies interrogating the diagnostic data of nipple discharge fluid cytology compared with the histopathology gold standard. Data from studies published from 1956 to 2019 were analyzed. The analysis included 8648 cytology samples of women with a presenting complaint of nipple discharge. Both hierarchical and bivariate models for diagnostic meta-analysis were used to attain overall pooled sensitivity and specificity.

Results

Of 837 studies retrieved, 45 fulfilled the criteria for inclusion. The diagnostic accuracy of the meta-analysis examining nipple discharge fluid had a sensitivity of 75 % (95 % confidence interval [CI], 0.74–0.77) and a specificity of 87 % (95 % CI, 0.86–0.87) for benign breast disease. For breast cancer, it had a sensitivity of 62 % (95 % CI, 0.53–0.71) and a specificity 71 % (95 % CI, 0.57–0.81). Furthermore, patients presenting with blood-stained discharge yielded an overall malignancy rate of 58 % (95 % CI, 0.54–0.60) with a positive predictive value (PPV) of 27 % (95 % CI, 0.17–0.36).

Conclusions

Pooled data from studies encompassing nipple discharge fluid assessment suggest that nipple smear cytology is of limited diagnostic accuracy. The authors recommend that a tailored approach to diagnosis be required given the variable sensitivities of currently available tests.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-11070-2.

Meta-analysis and cost-effectiveness of ductoscopy, duct excision surgery and MRI for the diagnosis and treatment of patients with pathological nipple discharge

INTRODUCTION

Pathological nipple discharge (PND) is a common breast-related complaint for referral to a surgical breast clinic because of its association with breast cancer. The aim of this meta-analysis was to compare the diagnostic efficacy of magnetic resonance imaging (MRI) and ductoscopy in patients with PND. Additionally, we determined the most cost-efficient strategy for the treatment of PND and the detection of breast cancer in PND patient without radiological suspicion for malignancy.

MATERIALS AND METHODS

PubMed and EMBASE were searched to collect the relevant literature from the inception of both diagnostic methods until January 27th 2020. The search yielded 815 original citations, of which 10 studies with 894 patients were finally included for analysis. Costs of ductoscopy, MRI and duct excision surgery were obtained from the UMC Utrecht as established in the year 2019. These costs included: medical personnel, overhead costs, material costs and sterilisation costs.

RESULTS

The meta-analysis showed no significant difference in sensitivity between ductoscopy (44%) and MRI (76%) for the detection of malignancy in patients with PND. However, ductoscopy (98%) had a statistically significantly higher specificity than MRI (84%). Individual costs were €1401.33, €822.13 and €6494.27 for ductoscopy, MRI and duct excision surgery, respectively. Full diagnostic strategy involving ductoscopy was on average €1670.97, while with MRI it was €2070.27.

CONCLUSION

Patients undergoing MRI are more often (false) positive which more often leads to duct excision surgery referrals compared to ductoscopy. This makes ductoscopy significantly more cost-effective compared MRI in patients with PND without radiological suspicion for malignancy.

Accuracy for cytological evaluation in the detection of breast cancer among patients with pathologic nipple discharge: a PRISMA-compliant meta-analysis

Background:

Nipple discharge cytology is a simple non-invasive method that may provide valuable information for detecting underlying malignancy. Several studies have investigated the diagnostic value of cytology in breast cancer patients with pathological nipple discharge, but the results have been highly variable. Herein we presented a systematic review and meta-analysis of published studies pertaining to the diagnostic capacity of nipple discharge cytology in patients with breast cancer.

Methods:

A systematic literature search was performed (Medline/PubMed, Embase, Cochrane Library databases, and Google Scholar) to identify studies that investigated the diagnostic capacity of cytology with regard to breast cancer in patients with pathologic nipple discharge. Two independent researchers identified articles that assessed the sensitivity and specificity of cytological evaluation for breast cancer detection in patients with pathologic nipple discharge published between January 2000 and October 2018. Articles were only included in the meta-analysis if they met predetermined criteria. The characteristics of each study and the data they yielded were summarized. Quality assessment of all articles included was performed using the Methodological Index for Non-randomized Studies Criteria (MINORS) and the Quality Assessment of Diagnostic Accuracy Study 2 (QUADAS-2). Heterogeneity was tested via Cochran Q test and the I² statistic using Stata 12.0 and Meta-DiSc 1.4 software, and meta-analysis was performed.

Results:

A total of 286 articles were identified, of which 12 articles including a total of 1476 patients were deemed eligible for inclusion in the meta-analysis. A random-effects model assessing the capacity of nipple discharge cytology to predict breast cancer yielded pooled sensitivity 63% (95% confidence interval [CI]: 53%–72%), specificity 95% (95% CI: 87%–98%), positive likelihood ratio 12.35 (95% CI: 4.87–31.34), and negative likelihood ratio 0.39 (95% CI: 0.30–0.50). The diagnostic odds ratio was 31.88 (95% CI: 11.30–89.98). The area under the summary receiver operating characteristic curve was 0.79 (95% CI: 0.75–0.82).

Conclusion:

The current meta-analysis suggests that nipple discharge cytology is a useful diagnostic modality for detection of breast cancer in patients with pathological nipple discharge, with moderate sensitivity and high specificity.

Advanced and futuristic approaches for breast cancer diagnosis

Background

Breast cancer is the most frequent cancer and one of the most common causes of death in women, impacting almost 2 million women each year. Tenacity or perseverance of breast cancer in women is very high these days with an extensive increasing rate of 3 to 5% every year. Along with hurdles faced during treatment of breast tumor, one of the crucial causes of delay in treatment is invasive and poor diagnostic techniques for breast cancer hence the early diagnosis of breast tumors will help us to improve its management and treatment in the initial stage.

Main body

Present review aims to explore diagnostic techniques for breast cancer that are currently being used, recent advancements that aids in prior detection and evaluation and are extensively focused on techniques that are going to be future of breast cancer detection with better efficiency and lesser pain to patients so that it helps to a physician to prevent delay in treatment of cancer. Here, we have discussed mammography and its advanced forms that are the need of current era, techniques involving radiation such as radionuclide methods, the potential of nanotechnology by using nanoparticle in breast cancer, and how the new inventions such as breath biopsy, and X-ray diffraction of hair can simply use as a prominent method in breast cancer early and easy detection tool.

Conclusion

It is observed significantly that advancement in detection techniques is helping in early diagnosis of breast cancer; however, we have to also focus on techniques that will improve the future of cancer diagnosis in like optical imaging and HER2 testing.

Patient-reported outcomes of ductoscopy procedures for pathologic nipple discharge

Background

Pathologic nipple discharge (PND) is a common complaint often associated with breast cancer. However, when ultrasound and mammography are negative, the chances of malignancy are lower than 5%. Currently, major duct excision and microdochectomy are often recommended to alleviate symptoms and definitely rule out malignancy, but can cause infections and breastfeeding problems. Ductoscopy is a minimally invasive endoscopy technique that allows visualization of the mammary ducts and may not only obviate surgery but also detect malignancy. The aim of this study was to determine quality of life (QOL) after ductoscopy in patients with PND.

Materials and methods

All PND patients referred for ductoscopy between 2014 and 2015 to our hospital were included. Ductoscopy procedures were performed under local anaesthesia in the outpatient clinic. Patients were asked to fill out questionnaires (Breast-Q, EQ-5D-5L and SF-36) on the day of ductoscopy, and after 2 weeks, 3 and 6 months. Additionally, we performed reliability analysis to determine if these questionnaires were suitable for PND patients.

Results

Fifty consecutive patients underwent ductoscopy of whom 47 patients participated in this study. One domain of SF-36 (vitality) varied significantly over time. Breast-Q, SF-36 and EQ-5D-5L showed that QOL after ductoscopy for PND was unaffected by ductoscopy. Success of the ductoscopy procedure was a significant predictor for satisfaction with the result domain.

Conclusion

Ductoscopy is a minimally invasive technique that does not seem to impact QoL of PND patients over time. Breast-Q, SF-36 and EQ-5D-5L seem to be suitable existing QOL tests for PND patients undergoing ductoscopy, whereas SF-36 would require modifications.

Utility of duct-washing cytology for detection of early breast cancer in patients with pathological nipple discharge: A comparative study with fine-needle aspiration cytology

BACKGROUND

Pathological nipple discharge (PND) is a relatively common symptom of breast cancer affecting the nipple. Mammary ductscopy (MD) allows direct visualization of the ductal lumen and collection of a cytological specimen using duct-washing cytology (DWC). Herein, we clarified the diagnostic efficacy of DWC for the detection of breast cancers with PND, compared with fine-needle aspiration cytology (FNAC).

METHODS

We retrospectively examined 48 patients with PND who underwent DWC by MD (ductosccopy group; histologically determined by intraductal biopsy [IDB] or surgical specimen). The results of sensitivity and specificity of DWC were compared with that of FNAC (conventional group; histologically determined by core needle biopsy). Clinicopathological factors were compared between the ductoscopy and the conventional groups.

RESULTS

Of eight histologically malignant cases in the ductoscopy group, one case was cytologically judged as malignant and three as indeterminate. Sensitivity and specificity of DWC were 50.0% and 82.5%, respectively. Malignant cases were mostly solid papillary carcinomas (SPCs), and benign cases were intraductal papillomas (IDPs). In the conventional group, sensitivity and specificity of FNAC were 88.0% and 38.2%, respectively, and malignant cases were mainly invasive carcinomas of no special type. Tumors in the ductocsopy group had more favorable prognostic features than those in the conventional group.

CONCLUSION

DWC has limited diagnostic value due to the high incidence of SPC, whose cytological features are indistinguishable from IDP. As DWC alone may be unreliable, comprehensive examination with IDB and MD findings is recommended.

Detection of breast cancer precursor lesions by autofluorescence ductoscopy

PURPOSE

Autofluorescence is an image enhancement technique used for the detection of cancer precursor lesions in pulmonary and gastrointestinal endoscopy. This study evaluated the feasibility of addition of autofluorescence to ductoscopy for the detection of intraductal breast cancer precursor lesions.

METHODS

An autofluorescence imaging system, producing real-time computed images combining fluorescence intensities, was coupled to a conventional white light ductoscopy system. Prior to surgery, ductoscopy with white light and autofluorescence was evaluated under general anaesthesia in women scheduled for therapeutic or prophylactic mastectomy. Endoscopic findings in both modes were compared, marked and correlated with histology of the surgical specimen.

RESULTS

Four breast cancer patients and five high-risk women, with a median age of 47 years (range 23-62) were included. In autofluorescence mode, two intraductal lesions were seen in two breast cancer patients, which had an increase in the red-to-green fluorescence intensity compared with the surrounding tissue. One lesion had initially been missed by white light ductoscopy but was clearly visible in subsequent autofluorescence mode. One endoscopic finding was classified as suspicious by white light, but was negative in autofluorescence mode and showed normal histology.

CONCLUSIONS

This study demonstrates for the first time the in vivo feasibility of autofluorescence ductoscopy to detect pathologically confirmed breast cancer precursor lesions in both breast cancer patients and high-risk women that were occult under white light.

Network Meta-analysis for the Diagnostic Approach to Pathologic Nipple Discharge

Pathologic nipple discharge (PND) is one of the most common breast-related complaints for referral because of its supposed association with breast cancer. The aim of this network meta-analysis (NMA) was to compare the diagnostic efficacy of ultrasound, mammogram, cytology, magnetic resonance imaging (MRI), and ductoscopy in patients with PND, as well as to determine the best diagnostic strategy to assess the risk of malignancy as cause for PND. Cochrane Library, PubMed, and Embase were searched to collect relevant literature from the inception of each of the diagnostic methods until January 27, 2020. The search yielded 1472 original citations, of which 36 studies with 3764 patients were finally included for analysis. Direct and indirect comparisons were performed using an NMA approach to evaluate the combined odd ratios and to determine the surface under the cumulative ranking curves (SUCRA) of the diagnostic value of different imaging methods for the detection of breast cancer in patients with PND. Additionally, a subgroup meta-analysis comparing ductoscopy to MRI when conventional imaging was negative was also performed. According to this NMA, sensitivity for detection of malignancy in patients with PND was highest for MRI (83%), followed by ductoscopy (58%), ultrasound (50%), cytology (38%), and mammogram (22%). Specificity was highest for mammogram (93%) followed by ductoscopy (92%), cytology (90%), MRI (76%), and ultrasound (69%). Diagnostic accuracy was the highest for ductoscopy (88%), followed by cytology (82%), MRI (77%), mammogram (76%), and ultrasound (65%). Subgroup meta-analysis (comparing ductoscopy to MRI when ultrasound and mammogram were negative) showed no significant difference in sensitivity, but ductoscopy was statistically significantly better with regard to specificity and diagnostic accuracy. The results from this NMA indicate that although ultrasound and mammogram may remain low-cost useful first choices for the detection of malignancy in patients with PND, ductoscopy outperforms most imaging techniques (especially MRI) and cytology.

Interventional Ductoscopy as an Alternative for Major Duct Excision or Microdochectomy in Women Suffering Pathologic Nipple Discharge: A Single-center Experience

INTRODUCTION

Pathologic nipple discharge (PND) is, after palpable lumps and pain, the most common breast-related reason for referral to the breast surgeon and is associated with breast cancer. However, with negative mammography and ultrasound, the chance of PND being caused by malignancy is between 5% and 8%. Nevertheless, most patients with PND still undergo surgery in order to rule out malignancy. Ductoscopy is a minimally invasive endoscopic technique that enables direct intraductal visualization. The aim of this study was to evaluate (interventional) ductoscopy as an alternative to surgery in patients with negative conventional imaging.

MATERIALS AND METHODS

All patients with PND referred between 2010 and 2017 to our hospital for ductoscopy were retrospectively analyzed. Ductoscopy procedures were performed under local anesthesia in the outpatient clinic. The follow-up period was at least 3 months, and the primary outcome was the number of prevented surgical procedures. Furthermore, we evaluated possible complications after ductoscopy (infection and pain).

RESULTS

A total of 215 consecutive patients undergoing ductoscopy were analyzed. In 151 (70.2%) patients, ductoscopy was successful. In 102 procedures, an underlying cause for PND was visualized, of which 34 patients could be histologically proven and 82 patients treated. Sixty of the 215 patients were eventually operated, 8 owing to suspicious findings during ductoscopy, 42 owing to persistent PND, and 10 because of recurrent PND. In 7 patients, a malignancy was found (5 of them classified as suspicious at dusctoscopy). No serious side effects were seen.

CONCLUSION

Ductoscopy can be safely used as an alternative for surgery in the workup for PND.

Comparison of ductoscopy, galactography, and imaging modalities for the evaluation of intraductal lesions: a critical review

BACKGROUND

Today, in cases of nipple discharge of unclear origin, the abundance of diagnostic procedures - a, diagnostic dilemma' - becomes apparent, because unequivocal indications and a current, standardized examination sequence are presently not available. The diagnostic workup of patients with nipple discharge usually includes the clinical history, physical examination, mammography, ultrasonography, galactography, and nipple discharge cytology, but not ductoscopy.

METHODS

In this review we analyze and discuss the possible role of ductoscopy in evaluating intraductal pathologies and its combined use with diagnostic imaging modalities. For this purpose, we reviewed and compared the results of the radiological, pathological, and surgical studies independently.

CONCLUSIONS

Currently, there is no solitary accurate modality to reach our definitive purpose. Being aware of the capability of each diagnostic modality may take us closer to our target. Therefore, adjunct and appropriate use of multiple imaging modalities and ductoscopy is necessary to evaluate patients with nipple discharge.

Nipple discharge: role of ductoscopy in comparison with standard diagnostic tests

BACKGROUND

This study aims to assess the role of ductoscopy for detecting intraductal anomalies in patients with nipple discharge in comparison to conventional tests and to find an effective combination of both approaches.

MATERIALS AND METHODS

Prior to duct excision, ductoscopy was performed in 97 women. Histologic and all other diagnostic results were compared. Sensitivity, specificity, and efficiency were calculated for all methods. These parameters were also calculated for all possible test combinations in 12 patients who had completed all tests.

RESULTS

Breast sonography reached the highest sensitivity (64.1%) and efficiency (64%); mammography had the highest specificity (100%). The sensitivity of ductoscopy was 53.2%, its specificity 60%, and its efficiency 55.1%. Among combinations of all methods, the combination ductoscopy + galactography was the most sensitive (80%). Mammography, magnetic resonance imaging, and ductoscopy were each 100% specific. Ductoscopy was the most efficient (75%) single method.

CONCLUSION

Ductoscopy is a valuable test for diagnosing intraductal lesions in patients with nipple discharge. It is more efficient than conventional tests in patients undergoing all tests.

High levels of DJ-1 protein in nipple fluid of patients with breast cancer

As we have previously demonstrated that some breast cancer cell lines secrete DJ-1 protein, we examined here whether breast cancer cells secrete DJ-1 protein in vivo. To this end, the levels of DJ-1 protein present in 136 specimens of nipple fluid was examined by enzyme-linked immunosorbent assay (ELISA). The average concentration of DJ-1 protein detected in diluted samples from 47 patients with invasive ductal carcinoma (IDC) was 22.4 ng/mL, while it was 18.6 ng/mL in 26 patients with ductal carcinoma in situ (DCIS). In contrast, the average DJ-1 concentration in samples from 63 women with benign lesions was 2.7 ng/mL, demonstrating that higher DJ-1 protein levels were detected in nipple fluid in the presence of cancer cells than in the presence of benign lesions (P < 0.0001). When a cut-off level of 3.0 ng/mL was applied, the higher level of DJ-1 was shown to be of significant clinical value for predicting the presence of breast cancer (85.9% specificity, 75% sensitivity; P < 0.0001). Multivariate logistic analysis that included established factors such as nipple discharge cytology, ductoscopic cytology, and carcinoembryonic antigen level further showed that the level of DJ-1 protein alone is of significant value for predicting the presence of breast cancer. Immunohistochemistry and in situ hybridization also showed that the low expression of DJ-1 protein, despite high mRNA expression, was significantly correlated with high DJ-1 protein levels in the nipple fluid. These data indicate that breast cancer cells secrete DJ-1 protein in vivo, and that its level is a potential indicator of breast cancer in patients with nipple discharge.

The diagnostic value of nipple discharge cytology: breast imaging complements predictive value of nipple discharge cytology

BACKGROUND

Papilloma is the most common finding associated with pathologic nipple discharge. In the absence of breast imaging abnormalities, the incidence of occult malignancy is <3%.

OBJECTIVE

To determine the predictive value of nipple discharge cytology in conjunction with breast imaging.

METHODS

Retrospective review of 160 charts; inclusion criteria of clinically pathologic nipple discharge, subsequent excisional biopsy, and absence of palpable abnormalities. Nipple discharge cytology categorized as negative, atypical, suspicious, and papillary. Breast imaging was analyzed. Preoperative tests were correlated to final surgical pathology.

RESULTS

89 patients identified. Sixty-five had positive cytology, with a false positive rate of 32.3%. They were associated with papillomas in 52%, benign non-papillary in 33% and malignant lesions in 9% of cases. Nipple discharge cytology was positive in 69.6% of papillomas and 92% of atypical/malignant lesions; 30% had abnormal breast imaging and positive cytology. Nipple discharge cytology had a sensitivity of 74.5%, specificity of 30%, and positive predictive value of 68%. The positive predictive value increased to 85% with associated abnormal breast imaging.

CONCLUSIONS

Nipple discharge cytology is useful in evaluating pathologic discharge. However, negative cytology with negative imaging is not enough to avoid surgery in cases of suspicious clinical presentation.

[The role of ductoscopy in the modern diagnostics and therapy of breast diseases]

Mammary ductoscopy is a modern, minimally invasive procedure that enables direct, in vivo observation of the mammary ductal system, primarily by nipple discharge. The rapidly developing device is suitable for aimed biopsy for further cytological or molecular examinations. High-tech equipments facilitate polypectomy or laser vaporization of certain intraluminal lesions, and play an important role in the direct surgical excision of the duct or the so-called terminal duct-lobular unit. The above listed facilitate the early diagnosis of malignancies even before imaging could detect them, and the control of high risk patients. Ductoscopy can foster surgical removal of ductal in situ tumors as anatomical units, thus enabling the optimization of radicality of breast conserving surgeries. Authors give a detailed description of the surgical techniques, and provide a wide review of the literature, for the first time in the Hungarian language. Orv. Hetil., 2011, 152, 1284-1293.

Basics of cytology

This overview is intended to give a general outline about the basics of Cytopathology. This is a field that is gaining tremendous momentum all over the world due to its speed, accuracy and cost effectiveness. This review will include a brief description about the history of cytology from its inception followed by recent developments. Discussion about the different types of specimens, whether exfoliative or aspiration will be presented with explanation of its rule as a screening and diagnostic test. A brief description of the indications, utilization, sensitivity, specificity, cost effectiveness, speed and accuracy will be carried out. The role that cytopathology plays in early detection of cancer will be emphasized. The ability to provide all types of ancillary studies necessary to make specific diagnosis that will dictate treatment protocols will be demonstrated. A brief description of the general rules of cytomorphology differentiating benign from malignant will be presented. Emphasis on communication between clinicians and pathologist will be underscored. The limitations and potential problems in the form of false positive and false negative will be briefly discussed. Few representative examples will be shown. A brief description of the different techniques in performing fine needle aspirations will be presented. General recommendation for the safest methods and hints to enhance the sensitivity of different sample procurement will be given. It is hoped that this review will benefit all practicing clinicians that may face certain diagnostic challenges requiring the use of cytological material.

Mammary ductoscopy and ductal washings for the evaluation of patients with pathologic nipple discharge

The majority of breast diseases result from lesions of the ductal epithelium. Mammary ductoscopy allows for visualization of intraductal abnormalities, and ductoscopic lavage provides thousands of cells for analysis. We reviewed our experience of 89 cases of patients with pathologic nipple discharge (PND) undergoing ductoscopy-directed duct excision and collection of ductal washings. Patients undergoing ductoscopy-directed duct excision with ductal washings had an 88% abnormal pathology rate. Most abnormalities were benign (71% papillomas), but the atypia rate for this group was 62%. The combination of visualization and pathologic analysis of washings provided the highest predictive value for the diagnosis of papilloma. Cellular yields for this technique were excellent with most specimens yielding >5,000 epithelial cells per high powered field and with evaluable ductal cells in 82% of specimens. Mammary ductoscopy offers the advantage of a high lesion localization rates with intraoperative guidance. The most accurate tool was the combination of ductal washings and ductoscopic visualization, but preoperative use of these techniques is not helpful in most cases. Greater than 90% of patients with PND are found to have a lesion on pathologic examination when using this technique for directed duct excision. Of interest, ductal washings obtained from symptomatic patients with benign diseases are often atypical.

Breast ductoscopy and the evolution of the intra-ductal approach to breast cancer

Interest in breast endoscopy came from Oriental investigators in the early 1990s where bloody nipple discharge is a more common presentation of breast cancer. The early techniques using a single microfiber scope without ductal distension was successful in navigating only the first 1-3 cm of the ducts and fraught with technical problems such as scope breakage and poor image quality. In spite of these barriers there has been increasing use of this technology in Japan and more widespread acceptance as the technology of scope design improved. Dooley and others tested a new method of obtaining a rich cytologic specimen from the ducts of high-risk women known as ductal lavage recently. The success of this procedure was that it detected severe cytologic and malignant atypia in clinically and radiographically normal breasts. Reproducibly, the same breast duct could be cannulated and severely atypical cytology obtained. The problem arose in identifying the lesion within the breast, which was the source for the atypia. New American multi-fiber microendoscopes were applied to solve this problem in an initial series of patients with abnormal cytology to identify the lesions. Success of that series lead to wider application of the imaging technology and eventual adoption of this imaging modality help to guide during all non-mastectomy breast surgery where fluid could be elicited from the nipple to identify the duct connecting to the lesion for which surgery was being performed. Initial reports have demonstrated the types of operative findings in certain sub-populations early in the use of this technology.

Ductal endoscopy of the breast: more painful at the luteal phase?

PURPOSE

To assess the putative predictors that may influence the pain experienced during ductal endoscopy of the breast.

METHODS

The pain experienced was evaluated in 19 consecutive premenopausal women with bloody nipple discharge scheduled for ductal endoscopy. The visual analog scale (VAS) was used to estimate the degree of pain. The duration of the procedure, the history of lactation, and the phase of the menstrual cycle were evaluated with respect to pain experienced. Statistical analysis followed.

RESULTS

The average reported pain (VAS score, mean +/- standard deviation) was 5.79 +/- 1.51 while the maximum pain was 8.26 +/- 0.99. The average reported pain was marginally associated with the duration of the procedure in contrast to the maximum. Women who were at the luteal phase of their menstrual cycle exhibited a higher average reported pain. The history of breastfeeding was not associated with the average reported pain, but it was associated with less intense maximum pain.

CONCLUSIONS

Pain during ductal endoscopy of the breast is influenced by a host of factors: some immutable (such as history of lactation) and others variable (day of menstrual cycle). The latter (ie, avoidance of the luteal phase) may be targeted for the minimization of pain.

Evaluation of pain experienced during breast ductal endoscopy

PURPOSE

Ductal endoscopy is valuable for the differential diagnosis of bloody nipple discharge; however, the pain associated with this procedure has not been evaluated. This study aims to assess the pain experienced by patients during ductal endoscopy.

METHODS

We studied a consecutive series of women who underwent ductal endoscopy, to investigate the cause of bloody nipple discharge. The procedure was performed using standard local anesthesia (lidocaine 1% 10 ml without epinephrine, involving nipple block and periaureolar administration). Patients were asked to score the level of pain with a visual analog scale, 1, 4, 7, 12, 17, 22, 27, and 32 min after the procedure, and describe their overall and maximum pain.

RESULTS

This series comprised 20 women aged from 27 to 68 years old. The overall pain (mean +/- SE) score was equal to 5.8 +/-0.3, and the maximum pain score was 8.3 +/- 0.2. The peak of pain corresponded with when the dilator was inserted through the sphincter. The group in which the dilator was inserted after 4 min experienced more intense maximum and overall pain after 7, 12, 17 and 22 min.

CONCLUSIONS

Pain is an important factor in ductal endoscopy, and peaks relatively early. A standard, baseline local lidocaine dose of greater than 10 ml may be necessary at the beginning of the procedure. Late insertion of the dilator seems to be an indicator of the force of the procedure.

The role and limitations of mammary ductoscope in management of pathologic nipple discharge

Mammary ductoscope allows visualization of the breast ductal wall and sampling of the abnormal area for diagnostic purposes. We are reporting our center experience in application of mammary ductoscope in detecting the underlying etiology of pathologic nipple discharge. Between November 2005 and December 2006 a total of 54 women, with spontaneous persistent nonlactational unilateral uniductal nipple discharge of no palpable lesions and negative breast sono-mammography, were included in the study for morphologic assessment of ductal epithelium, ductal lavage and ductoscopically guided procedures as punch biopsy and ductoscopically guided microdochectomy. Forty-one patients (76%) with nipple discharge were positive ductoscopically. Thirteen patients (24%) appeared normal. Ductoscopic lavage has a much more cellular yield than ordinary squeezing cytology. Ductal thickening by the ductoscope (11 cases) revealed to be hyperplasia on pathology (five cases), papilloma (two cases), atypical ductal hyperplasia (two cases), ductal carcinoma in situ (one case), and invasive breast carcinoma (one case). There was a significant association between intraductal visual observations and histopathologic diagnosis. Mammary Ductoscope is a promising tool in management of pathologic nipple discharge. Biopsy and ablation techniques can be performed during ductoscopy with correlation between visual findings and histopathology, but there are still some limitations of in clinical practice.

Autofluorescence Ductoscopy: A New Imaging Technique for Intraductal Breast Endoscopy

BACKGROUND

Conventional diagnostic imaging techniques of the female breast, eg, ultrasound, mammography, breast magnetic resonance imaging, or ductography, can only give indirect information about the inside of breast ducts. Diagnostic ductoscopy is the first approach for direct visualization of intraductal lesions. Autofluorescence ductoscopy is a new, noninvasive imaging technique that better identifies intraductal lesions under direct vision.

MATERIALS AND METHODS

We describe the technical development of autofluorescence ductoscopy and initial experience with early clinical evaluation at Frauenklinik (OB/GYN) of Technical University Munich, Germany, and its potential future application. In contrast to standard white light breast endoscopy, autofluorescence ductoscopy uses a different light spectrum and, after sophisticated data processing, can mark suspicious intraductal lesions in blue-violet colors. Autofluorescence ductoscopy adds new visual information previously not seen in white-light endoscopy. Technical development is completed and clinical evaluation is under way.

RESULTS

In a small series, the autofluorescence ductoscope was used and confirmed the initial expectations. No complication was expected or occurred. At present time, it is being used on an experimental basis for evaluation of its clinical benefits.

CONCLUSION

The clinical evaluation of autofluorescence ductoscopy is a work in progress at an early stage. This technique is intended to improve visualization and identification of breast duct walls and lesions and possibly allows an instant visual semiquantitative histologic evaluation of nonbenign ductal lesions.

Diagnostic value of ductoscopy in the diagnosis of nipple discharge and intraductal proliferations in comparison to standard methods

BACKGROUND

Ductoscopy is gaining increased importance in the diagnosis of nipple discharge of unclear origin and intraductal proliferation. For this reason we compared its diagnostic value and feasibility to standard diagnostic methods.

MATERIAL AND METHODS

Ductoscopy was compared to mammography, galactography, sonography, magnetic resonance imaging (MRI), nipple smear, fine needle aspiration cytology (FNAC), and high-speed core biopsy; feasibility, sensitivity, and specificity were investigated for each method.

RESULTS

71 ductoscopies were evaluated, which were followed up by open biopsies. Here, 3 invasive and 8 ductal carcinomas in situ were found, as well as 3 atypical ductal hyperplasias, 44 papillomas/papillomatoses, and 13 benign findings. Feasibility of ductoscopy was in this series 100%. Duct sonography showed the highest sensitivity (67.3%), followed by MRI (65.2%), galactography (56.3%), ductoscopy (55.2%), and FNAC (51.9%). The highest specificity was shown by FNAC, core biopsy, and galactography (each 100.0%), followed by mammography (92.3%), nipple smear (77.8%), ductoscopy, and duct sonography (each 61.5%); the lowest specificity was displayed by MRI (25.0%).

CONCLUSION

The results confirm that ductoscopy can be performed within the same range of sensitivity and specificity as other techniques. In order to make conclusive statements about ductoscopy, especially in order to precisely define the indications for this method, a prospective multicenter study was initiated.

Mammary ductoscopy for the evaluation of nipple discharge and comparison with standard diagnostic techniques

STUDY OBJECTIVE

To describe performance of breast duct endoscopy and compare the method with conventional diagnostic techniques.

DESIGN

Canadian Task Force classification III.

SETTING

Interdisciplinary Breast Unit of a university hospital.

PATIENTS

Consecutive and unselected series of 15 female patients including 20 breasts with nipple discharge.

INTERVENTIONS

Prospective data assessment on all patients with ductoscopy for nipple discharge between April 2003 to April 2004. All preoperative (mammography, ultrasonography, nipple smear) and minimally invasive (galactography, fine needle aspiration cytologic study) diagnostics were evaluated and compared with ductoscopy.

MEASUREMENTS AND MAIN RESULTS

Mammography on 20 breasts showed BI-RADS-I (5%), BI-RADS-II (50%), and BI-RADS-III (45%). Breast ultrasound scanning showed abnormalities, classified as BI-RADS-III equivalent lesions in all cases. Nipple smear showed in 69.2% a normal cytology and in most cases revealed a papilloma later (n=8/9). Unilateral galactography was performed in 46.7% who had spontaneous nipple discharge. Two galactography results were unremarkable, and open biopsy demonstrated 1 atypical ductal hyperplasia and papilloma. On 20 breasts of 15 women, 19 ductoscopies were successfully performed (95%). In 17 cases open biopsy followed ductoscopy, and 1 ductal carcinoma in situ (DCIS), 3 atypical ductal hyperplasia (ADH), 1 ductal hyperplasia without atypias, and 12 ductal papillomas were found.

CONCLUSION

Compared to nipple smear, the diagnostic value of ductoscopy in this study is superior but marginally inferior to galactography and highly specialized breast ultrasound scanning. Therefore ductoscopy needs to be evaluated on a larger scale, preferably in multicenter trials to further determine its potential and indications.

Clinical Experience With Mammary Ductoscopy

BACKGROUND

Most breast cancers begin in the ductal epithelium with normal cells and progress to atypia and finally to carcinoma. Mammary ductoscopy enables one to directly visualize and sample the ductal epithelium and, therefore, identify early changes cytologically. This article describes our initial experience with mammary ductoscopy at Beth Israel Medical Center.

METHODS

A prospective review of all patients who underwent ductoscopy at Beth Israel Medical Center from November 2001 to February 2004 was performed. The indications for ductoscopy were a persistent nipple discharge, high-risk status, or intraoperative margin assessment in patients undergoing lumpectomy.

RESULTS

Seventy-four patients underwent ductoscopic evaluation of 88 ducts. Of the 32 patients who underwent office ductoscopy, 15 were high risk, and 17 had spontaneous nipple discharge. Spontaneous nipple discharge was the indication for ductoscopy in 40 of 42 intraoperative procedures. The remaining two patients underwent ductoscopy for margin assessment during breast conservation, and final pathologic analysis revealed negative margins. Thirty-eight of the 40 patients who had spontaneous nipple discharge had abnormal findings during ductoscopy and therefore underwent ductoscopically guided duct excision. Carcinoma was the final diagnosis in 5 (8.8%) of the 57 patients who were scoped for nipple discharge.

CONCLUSIONS

Mammary ductoscopy is a potentially useful tool in the evaluation of patients with spontaneous nipple discharge. This is a well-tolerated office procedure with minimal risks and complications. Mammary ductoscopy may have a role in the assessment of high-risk women. Further research is necessary to confirm these potential applications.

Ductoscopy and intraductal vacuum assisted biopsy in women with pathologic nipple discharge

BACKGROUND

Fiberoptic ductoscopy is increasingly used to evaluate pathologic nipple discharge. A major limitation of this technique is the inability to obtain tissue samples from suspicious intraductal lesions. We present a novel technique for ductoscopic biopsy of intraluminal tumors.

METHODS

From 2002 to 2005 ductoscopy was performed in 38 women with nipple discharge using a rigid gradient index microendoscope (diameter 0.7 mm) and a special needle for intraductal vacuum assisted biopsy. Results of preoperative biopsy were correlated with the histology of the resection specimen

RESULTS

Cannulation of the discharging duct was successful in 37 of 38 patients (97%). Intraductal lesions were diagnosed in 29 women (78%). The sensitivity of ductoscopy and galactography in the detection of intraductal lesion was comparable (96% vs. 89%). Ductoscopic biopsy of intraductal lesions was technically successful in all but one case. Generally, the quality of the biopsy samples was good. Diagnostic biopsy samples were obtained in 26 of 28 patients (93%). Two samples contained necrosis and were considered to be non-representative. Histological analysis of the biopsy specimens showed 22 papilloma, 2 in situ carcinoma and 2 invasive carcinoma. Histology of the resection specimens confirmed the diagnosis in all cases, but there was one case with additional carcinoma lobulare in situ.

CONCLUSIONS

Ductoscopic vacuum assisted biopsy is a new technique for tissue sampling of intraductal breast lesions. This method may improve preoperative evaluation of pathologic nipple discharge in selected patients, but it should not be considered as a method for screening of early breast cancer.

The future prospect: ductoscopy-directed brushing and biopsy

The intraductal approach to breast cancer and premalignant lesions has now developed to yield substantial cytologic samples of exfoliated cells. Standard cytology is still inadequate in sensitivity and specificity to accurately interpret the majority of samples. As techniques evolve using ductoscopic biopsy and molecular marker panels to increase accuracy of cytologic interpretation, these tools will be able to unravel the breast carcinogenesis pathways. They will also offer considerable benefit in screening for premalignant changes and developing effective chemoprevention strategies.

Breast duct microendoscopy in nipple discharge: microbrush improves cytology

BACKGROUND

Breast duct microendoscopy is a new technique that allows direct visualization of the mammary ductal epithelia and has the potential to provide greater accuracy in the diagnosis of benign and malignant breast conditions. We have already established the feasibility of BDME on mastectomy specimens and in patients both under general and local anesthesia. It was the aim of this study to investigate the use of BDME in patients with pathological nipple discharge and to explore the feasibility of using an endoluminal microbrush to take cytology samples from specific lesions.

MATERIALS AND METHODS

Breast duct microendoscopy was offered to all patients undergoing surgery for nipple discharge. Surgery included microdochectomy (younger women) and total duct excision (especially in postmenopausal women). The microbrush was used to collect samples whenever an endoluminal papilloma was seen on endoscopy. The results of microbrush cytology samples were compared to ductal lavage samples.

RESULTS

Fifty consecutive patients undergoing microdochectomy or total duct excision for nipple discharge had breast microendoscopy (28 general, and 22 under local anesthesia). Thirty-one patients had microdochectomy and nineteen had total duct excision. Visualiza- tion of discharging ducts was accomplished in 100% cases. Endoluminal abnormalities were seen in 33 (66%) patients and dilated ducts were seen in 17 patients. Among the 33 patients, 15 had single papilloma, 3 multiple papilloma and 15 inflammation (erythema, fronds, adhesions). Seven out of eight patients with an intraductal papillorna who had microbrush cytology showed papillary cells whereas only 2 out of 11 patients who had ductal lavage were positive for papillary cells. Thus the sensitivity of the brush cytology technique for the diagnosis of papilloma was 87.5% and the sensitivity of ductal lavage 18% (p = 0.0055).

CONCLUSION

Breast duct microendoscopy is an effective way of establishing the etiology of nipple discharge. The microbrush increases the sensitivity of cytology significantly.

Breast ductoscopy with a 0.55-mm mini-endoscope for direct visualization of intraductal lesions

Standard radiologic examinations of breast duct lesions can give only indirect information. Mini-endoscopy with a breast ductoscope of only 0.55 mm offers direct visualization of the lesion and helps in the decision to perform or avoid exploratory breast tissue resection. We used a LaDuScope (PolyDiagnost, Pfaffenhofen, Germany) with a 0.55- or 0.95-mm outer diameter and a 75-mm working length from October 2003 through July 2004 on 11 women (average age of 48.3 years [range 36-69 years]) with suspicious nipple discharge. The optics have zero-degree direct view, 70-degree field vision, and 3000 or 6000 pixel resolution. Breast ducts and walls could be easily inspected; and irrigation of breast ducts, aspiration, and use of cytology brush were possible under visual control. We had no intraoperative or postoperative complications. The new procedure of mini-ductoscopy is feasible, safe, and helpful as an additional ambulatory diagnostic method for visual inspection of breast ducts. This instrument demonstrates the latest advances of technology and a trend toward less-invasive diagnostics for breast duct lesions.

Effect of perductal paclitaxel exposure on the development of MNU-induced mammary carcinoma in female S-D rats

BACKGROUND

Breast carcinoma and precancer are thought to start in the lining of the milk duct or lobule.

METHODS

At 5weeks of age, rats received a intraperitoneal (ip) injection of MNU for carcinogenesis. After mammary tumors were identified macroscopically using fiberscope, the rats were treated with perductal (pd) or ip injection of paclitaxel tri-weekly. At 36 weeks after MNU injection, tumor burden (No. of >1cm palpable mammary tumors/rat), total number of mammary carcinoma, apoptosis (AI), and microvessel density (MVD) were measured.

RESULTS

The administration of paclitaxel through the duct did not produce any toxic side effect. The tumor burden and total number of mammary carcinoma in the pd paclitaxel-treated group were significantly reduced compared to those seen in the ip paclitaxel-treated group. In addition, in the pd paclitaxel-treated group, AI was also increased and MVD was decreased, compared to those in the ip paclitaxel-treated group.

CONCLUSION

Local administration of paclitaxel may be useful for treatment of breast cancer.

Pathologic Nipple Discharge: Surgery Is Imperative in Postmenopausal Women

BACKGROUND

A total of 10% to 15% of pathologic nipple discharge in women is due to malignant lesions of the breast. The purpose of this study was to discover the rate of breast cancer in women who present with this symptom and undergo ductal excision, to evaluate the different diagnostic methods used before surgery, and to discover whether there are specific factors with regard to dignity.

METHODS

We analyzed 118 ductal excisions in 116 patients performed at the women's hospital of the University of Rostock, Germany, between 1995 and 2002. The discharging duct was identified by preoperative galactography.

RESULTS

The rate of cancer in these patients was 9.3% (n = 11). The most frequent benign lesion was intraductal papillomatous proliferation (36.4%; n = 43). Solitary papillomas were shown in 21.2% (n = 25), and other specific benign histologic findings were shown in 27.1% (n = 32). Women with malignancies were significantly older (P = .009) and were more often postmenopausal (P = .095) compared with patients with benign histology. Galactography was the method that reached the highest sensitivity (73%), and clinical examination showed the highest specificity (85%) in distinguishing between benign and malignant lesions.

CONCLUSIONS

Because 94.1% of all cases presented with specific histological findings causing pathologic nipple discharge, ductal excision combined with preoperative galactography was proven to be a sufficient method for diagnosis and therapy. This procedure should be performed in all postmenopausal women with this symptom because of a cancer rate of 12.7% among this age group and the unsatisfactory quality of other diagnostic methods.

Ductal Lavage Using Medically Aseptic Technique in Women at High Risk for Breast Cancer

Ductal lavage of the breast is a minimally invasive procedure used to collect epithelial cells from the lumen of the ductolobular system for cytologic analysis. The purpose of this study was to determine the safety of using an aseptic technique in performing ductal lavage. The study included 114 consecutive patients at high risk for breast cancer with clinically negative mammograms and no palpable masses. Ductal lavage could not be performed on 32 of the 114 patients (28%): 26 because nipple aspirate fluid could not be obtained, and 6 because a fluid-yielding duct could not be cannulated. Ductal lavage was successfully performed on 82 patients (72%). Local anesthetic cream was used on the nipple area and local anesthetic was infused into each duct. The nipple, the cup of the nipple aspirator device, and any dilator tools were cleansed with alcohol before use. Separate sterile microcatheters were used for each duct. Sterile saline solution was used for the infusions. No patient reported any symptoms indicating infection after lavage. Cytologic analysis from the 82 lavage cases showed 45 benign cells (55%), 17 cases of mild atypia (21%), 1 case of marked atypia, and 1 case with malignant cells. Eighteen samples (22%) had inadequate cellularity for medical diagnosis. The results of the study indicate that an aseptic technique is safe and appropriate for ductal lavage of the breast.

Office-based breast ductoscopy for diagnosis

OBJECTIVE

Ductoscopy is an evolving technology that has been used primarily and historically in conjunction with open surgical procedures. New technical improvements allow intraductal biopsy and therefore its application in the clinical setting for diagnostic evaluations of the breast. This study looks at the initial use of intraductal biopsy in a variety of settings from an academic university practice to a private single-surgeon office.

METHODS

This is a multicenter retrospective series of 88 patients undergoing ductoscopy of > or =1 duct for the diagnostic workup of common breast problems. The procedures were done with the patient under local anesthesia, and intraductal biopsy specimens were taken and analyzed as breast cytology samples.

RESULTS

Of the 88 patients undergoing office ductoscopy, nipple discharge was the most common indication (n = 83 patients; 94% to 66% spontaneous and 34% elicited). Fifty-five percent were high risk for breast cancer by history. The majority of patients had normal previous mammograms: 48 Breast Imaging-Reporting and Data System (BIRADS) 1, 24 BIRADS 2, and 7 BIRADS 3 to 5. The most common finding was papilloma present in 29 (32%) patients by endoscopy. Only 31% of patients had a history of brown or bloody nipple discharge. A wide variety of other endoscopic abnormalities were seen and biopsied. The average number of biopsies per patient was 2 with 18 (20.5%) having severe or malignant atypia. Further follow-up and management of these more concerning abnormalities is currently ongoing.

CONCLUSIONS

These results indicate that office ductoscopy with biopsy is both feasible and does identify suspicious or malignant atypia in patients with expressed or spontaneous nipple fluid.

A Review of Mammary Ductoscopy in Breast Cancer

Breast carcinoma and hyperplasia are thought to start in the lining of the breast duct. Mammary ductoscopy is an emerging technique allowing direct visual access of the ductal system of the breast through the nipple. This article reviews and discusses the utility of mammary ductoscopy. Abnormalities can be identified successfully by mammary ductoscopy, and intraductal biopsy can be used when the tumor is a polypoid type. Ductal lavage using microcatheters is effective in identifying malignant cells in high-risk women and this has stimulated interest in exploring the role of mammary ductoscopy in breast cancer screening. Mammary ductoscopy combined with ductal lavage may have a role in the management of patients with nipple discharge, the guiding of breast-conserving surgery for cancer, and in screening for high-risk women. The addition of molecular and genetic analysis of cells obtained by mammary ductoscopy are likely to enhance the use of this technique. Mammary ductoscopy techniques are safe and appear useful for detecting abnormalities in the breast. The additional molecular biologic study or ductal lavage may enhance the ability to direct and limit subsequent surgery when removing the offending lesions.

Intraductal biopsy for diagnosis and treatment of intraductal lesions of the breast

BACKGROUND

Bloody nipple discharge is a significant clue in the detection of ductal carcinoma of the breast. In the past, pathologic diagnoses were obtained exclusively via excision, but recently developed mammoscopic techniques have been found to yield valuable information relating to the diagnosis of intraductal lesions.

METHODS

Mammary duct endoscopy (i.e., mammoscopy) was performed a combined total of 407 times for 295 patients who experienced nipple discharge. Intraductal breast biopsy (IDBB) under mammoscopic observation was performed in 193 intraductal papillomas (from a total of 107 patients) and 30 ductal carcinomas (from a total of 27 patients); IDBB was performed a combined total of 36 times in the 27 patients who had breast carcinoma and yielded 21 diagnostic specimens (58.3%). In addition, the therapeutic value of IDBB was assessed in 70 patients with intraductal papilloma who had undergone more than 3 years of follow-up; these 70 patients harbored a combined total of 75 intraductal papillomas.

RESULTS

IDBB correctly identified the presence of carcinoma in 9 of 27 patients (33.3%); 7 other lesions (25.9%) were placed in the suspected carcinoma (i.e., atypical papillary lesion) category, and 5 (18.5%) were identified as intraductal papillomas. Using IDBB, it was difficult to collect diagnostic specimens from patients with breast carcinoma, because of the location and weak tissue cohesiveness of these lesions compared with intraductal papillomas. The 193 intraductal biopsies performed on intraductal papillomas yielded only 20 specimens that were insufficient for diagnosis. IDBB exhibited therapeutic efficacy in 54 of 70 patients with intraductal papilloma (77.6%) who had more than 3 years of clinical follow-up. Therapeutic results tended to be less favorable for patients who had intraductal lesions in multiple duct lobular units.

CONCLUSIONS

Mammoscopy can contribute not only to the diagnosis of cases of nipple discharge but also to the treatment of intraductal papilloma.

Mammogram synthesis using a three-dimensional simulation. III. Modeling and evaluation of the breast ductal network

A method is proposed for realistic simulation of the breast ductal network as part of a computer three-dimensional (3-D) breast phantom. The ductal network is simulated using tree models. Synthetic trees are generated based upon a description of ductal branching by ramification matrices (R matrices), whose elements represent the probabilities of branching at various levels of a tree. We simulated the ductal network of the breast, consisting of multiple lobes, by random binary trees (RBT). Each lobe extends from the ampulla and consists of branching ductal segments of decreasing size, and the associated terminal ductal-lobular units. The lobes follow curved paths that project from the nipple toward the chest wall. We have evaluated the RBT model by comparing manually-traced ductal networks from 25 projections of ductal lobes in clinical galactograms and manually-traced networks from 23 projections of synthetic RBTs. A root-mean-square (rms) fractional error of 41%, between the R-matrix elements corresponding to clinical and synthetic images, was computed. This difference was influenced by projection and segmentation artifacts and by the limited number of available images. In addition, we analyzed 23 synthetic trees generated using R matrices computed from clinical images. A comparison of these synthetic and clinical images yielded a rms fractional error of 11%, suggesting the possibility that a more appropriate model of the ductal branching morphology may be developed. Rejection of the RBT model also suggests the existence of a relationship between ductal branching morphology and the state of mammary developmentand pathology.