Treatment Strategy for Breast Benign Intraductal Papilloma: A Meta-Analysis.

Currently, the optimal treatment approach for breast benign intraductal papilloma (IDP) diagnosed via biopsy remains uncertain. There is ongoing debate regarding the feasibility of clinical follow-up and the criteria for selective surgical excision. This study aims to conduct a meta-analysis to determine the rate of upgrade from breast benign IDP and identify predictive factors associated with the conversion of benign IDP to high-risk lesions or carcinoma, which could guide healthcare practitioners in selecting the appropriate clinical treatment strategy. We conducted a comprehensive search across multiple databases (PubMed, Web Of Science, Cochrane Library, and Embase) for studies published between 2012 and 2023 that evaluated upgrade rates and predictive factors of breast benign IDP diagnosed via biopsy. In addition, we included studies that reported on the clinical follow-up of patients with breast benign IDP. In total, 32 studies comprising 7371 cases of biopsy-diagnosed breast benign IDP were included. Among these cases, 720 demonstrated an upgrade to high-risk lesions or carcinoma, resulting in an upgrade rate of 6.94% [95% confidence interval (CI): 3.0-8.0%]. A subgroup of 1713 patients was clinically followed up, demonstrating an average follow-up duration of 30.95 months. Among them, 26 cases experienced an upgrade to high-risk lesions or carcinoma, yielding an upgrade rate of 1.51% (95% CI 0.00-2.00). Furthermore, we identified nine predictive factors associated with the upgrading of breast benign IDP, which included age at diagnosis, personal history of breast cancer, family history of breast cancer, multiple IDPs, lesion size ≥ 10 mm, palpable mass, calcification, and the presence of mass and asymmetry in mammographic findings. Although the conversion rate of breast benign IDP to high-risk lesions or carcinoma is relatively low, timely identification of predictive factors associated with benign IDP upgrades may help selecting the optimal clinical treatment strategy, such as surgery for patients with benign IDP presenting one or more predictive factors, while clinical follow-up for those without specific risk factors.

Challenging diagnosis of male intraductal papilloma masquerading as eccrine hidradenoma in the breast: Case report.

RATIONALE: This article presents a challenging case involving an elderly male patient with a misdiagnosed intraductal mammary papilloma initially identified as a sweat adenoma through ultrasound imaging. The study aims to explore the histopathology, clinical presentations, and sonographic features of both conditions, emphasizing the contributing factors to the diagnostic misstep. PATIENT CONCERNS: A 61-year-old male reported a persistent left breast mass, along with pain and swelling, spanning a 6-month duration. DIAGNOSES: Ultrasound examination indicated a deep, square, mixed-echo mass in the left nipple, initially suggestive of a sweat adenoma. However, subsequent pathological analysis following resection under general anesthesia confirmed an intraductal papilloma. INTERVENTION: The patient underwent surgical resection of the left breast mass under general anesthesia. OUTCOME: Post-surgery, the patient exhibited satisfactory recovery; however, regrettably, he was lost to follow-up. LESSONS: This study underscores the challenge in differentiating between clear cell sweat adenoma and male intraductal mammary papilloma solely based on ultrasonic characteristics. It emphasizes the susceptibility of ultrasound-based diagnoses to misinterpretation, highlighting the critical need for a comprehensive pathological examination to establish a definitive diagnosis.

The Diagnostic Value of microRNA Expression Analysis in Detecting Intraductal Papillomas in Patients with Pathological Nipple Discharge.

Patients with pathological nipple discharge (PND) often undergo local surgical procedures because standard radiologic imaging fails to identify the underlying cause. MicroRNA (MiRNA) expression analysis of nipple fluid holds potential for distinguishing between breast diseases. This study aimed to compare miRNA expression levels between nipple fluids from patients with PND to identify possible relevant miRNAs that could differentiate between intraductal papillomas and no abnormalities in the breast tissue. Nipple fluid samples from patients with PND without radiological and pathological suspicion for malignancy who underwent a ductoscopy procedure were analyzed. We used univariate and multivariate regression analyses to identify nipple fluid miRNAs differing between pathologically confirmed papillomas and breast tissue without abnormalities. A total of 27 nipple fluid samples from patients with PND were included for miRNA expression analysis. Out of the 22 miRNAs examined, only miR-145-5p was significantly differentially expressed (upregulated) in nipple fluid from patients with an intraductal papilloma compared to patients showing no breast abnormalities (OR 4.76, p = 0.046), with a diagnostic accuracy of 92%. miR-145-5p expression in nipple fluid differs for intraductal papillomas and breast tissue without abnormalities and, therefore, has potential as a diagnostic marker to signal presence of papillomas in PND patients. However, further refinement and validation in clinical trials are necessary to establish its clinical applicability.

Malignant upgrade rate and associated clinicopathologic predictors for concordant intraductal papilloma without atypia: A systematic review and meta-analysis.

Previously reported upgrade rates for benign breast intraductal papilloma (IDP) are widely variable. However, many previous studies have failed to consider radiologic-pathologic discordance of lesions. This review aims to synthesize malignant upgrade data for benign, concordant IDP at surgical excision. Thirteen studies were included in our meta-analysis. The pooled estimate for percentage underestimation of carcinoma was 1.4% (95% CI: 0.8%-2.0%). We conclude that these lesions can be safely managed by active surveillance.

The "Trunk sign": A novel X-ray sign in galactography of patients with nipple discharge suggesting malignancy.

The etiology of nipple discharge is often unclear, and there are few studies exploring diagnostic approaches of nipple discharge. Galactography is a common method for clinical diagnosis of patients with nipple discharge. Therefore, this study aimed to evaluate the use of galactography in differentiating between benign and malignant lesions in patients with nipple discharge. A retrospective study of 161 patients with nipple discharges, who were evaluated with galactography and underwent surgery in Qilu Hospital of Shangdong University between January 2018 and December 2019, was conducted. Baseline characteristics were obtained from their electronic records including age, menstruation status, physical examination, galactography, cytology, and pathology. There were 110 cases of benign disease, 12 cases of high-risk disease, and 39 cases of malignant disease. With respect to benign diseases there were 26 (23.6%) patients with hyperplasia and ductal ectasia, and 94 (76.4%) with intraductal papilloma. With respect to high risk diseases, there were 2 (16.7%) patients with atypical intraductal papilloma and 10 (83.4%) with atypical hyperplasia. With respect to malignant lesions, 19 (48.7%) patients had intraductal carcinoma, 4 (10.3%) had solid papillary carcinoma, and 16 (41.0%) had invasive carcinoma. The significant findings of our study are as follows: patients with malignant diseases had a higher proportion of concomitant masses (74.4% vs 41.7% vs 22.7%, P < .001), positive spill cytology (51.3% vs 41.7% vs 2.7%, P < .001), and trunk signs (71.8% vs 33.3% vs 10.9%, P < .001). A forest plot revealed that trunk signs were related to an increased risk of malignant diseases in almost all the subgroups. Galactography is important for the differential diagnosis of benign and malignant lesions in nipple discharge, and the "Trunk sign" is an important radiographic sign of malignant lesions. Combining galactography with other methods is advisable to improve the accuracy of diagnosis in patients with nipple discharge.

Diagnostic and Therapeutic Roles of Microdochectomy and Subareolar Ducts Excision for Pathological Nipple Discharge in Lagos.

BACKGROUND: Pathological nipple discharge (PND) comprises less than 10% of presentation in breast clinics. Data on the management of nipple discharge (ND) in our environment are scarce. AIM: To review management outcome in cohorts of patients with PND in our institution between December 2010 and October 2020. METHODOLOGY: This is a retrospective review of consecutive patients managed for PND between 2010 and 2020. Demographical characteristics, clinical features, investigation results and management outcome were retrieved from the clinical records for analysis. A cross-sectional survey via telephone conversation/clinic consultation was carried out to monitor patients for post-operative complications and recurrence. RESULTS: There were 25 patients (18 microdochectomies and 7 subareolar duct excisions) in the study with a median age of 44 (37.5-49.5) years. The median duration of symptoms before presentation was 3 (2.5-5.5) months. The major characteristics of ND in the study cohort were: single duct orifice in 18 patients (72%) spontaneous ND in 14 patients (56%); right ND in 15 patients (60%); and bloody ND in 21 patients (84 %). Only one patient had a family history of breast cancer. Intraductal papilloma diagnosed in 9 patients (36%) was the most common cause of PND. Breast cancer was an underlying aetiology in 28% of patients in the series. Six out of 7 patients with breast cancer diagnosis were <50years. CONCLUSION: Most women with PND in our practice were young with predominance of spontaneous bloody discharge. Intraductal papilloma was the most common cause of PND in this study. Breast cancer accounted for about a third of cases.

CONTEXTE: L'écoulement mamelonnaire pathologique (EMP) représente moins de 10 % des cas présentés dans les cliniques du sein. Les données sur la prise en charge de l'écoulement mamelonnaire (EM) dans notre environnement sont rares. OBJECTIF: Examiner les résultats de la prise en charge dans des cohortes de patientes présentant un écoulement mamelonnaire pathologique dans notre établissement entre décembre 2010 et octobre 2020. MÉTHODOLOGIE: Il s'agit d'une revue rétrospective des patientes consécutives prises en charge pour un DP entre 2010 et 2020. Les caractéristiques démographiques, les caractéristiques cliniques, les résultats des examens et les résultats de la prise en charge ont été extraits des dossiers cliniques pour analyse. Une enquête transversale par conversation téléphonique/consultation en clinique a été réalisée pour surveiller les complications post-opératoires et les récidives chez les patients. RÉSULTATS: L'étude a porté sur 25 patients (18 microdochectomies et 7 excisions du canal sous-aréolaire) dont l'âge médian était de 44 ans (37,5-49,5). La durée médiane des symptômes avant la consultation était de 3 (2,5-5,5) mois. Les principales caractéristiques de la MN dans la cohorte de l'étude étaient les suivantes : orifice unique dans 18 patients (72 %), MN spontanée chez 14 patients (56%), MN droite chez 15 patients (60 %) et MN sanglante chez 21 patients (84 %). Une seule patiente avait des antécédents familiaux de cancer du sein. Le papillome intraductal diagnostiqué chez 9 patientes (36 %) était la cause la plus fréquente de la MN. Le cancer du sein était une cause sous-jacente chez 28 % des patientes de la série. Six des sept patientes chez qui un cancer du sein a été diagnostiqué avaient moins de 50 ans. CONCLUSION: Dans notre pratique, la plupart des femmes souffrant de DPN étaient jeunes, avec une prédominance d'écoulements sanglants spontanés. Le papillome intraductal était la cause la plus fréquente de DPN dans cette étude. Le cancer du sein représentait environ un tiers des cas. Mots-clés: Cancer du sein, Écoulement, Mamelon, Pathologique.

Intraductal papilloma with atypical ductal hyperplasia and neuroendocrine differentiation as a possible precursor lesion of solid papillary carcinoma.

Breast papillary neoplasms include a wide range of tumor types, and their pathological diagnosis is sometimes difficult. Furthermore, the etiology of these lesions is still not fully understood. We report the case of a 72-years-old woman referred to our hospital with bloody discharge from the right nipple. An imaging study detected a cystic lesion, including a solid component contiguous with the mammary duct, in the subareolar region. The lesion was then removed by segmental mastectomy. Pathological examination of the resected specimen revealed an intraductal papilloma with atypical ductal hyperplasia. Moreover, the atypical ductal epithelial cells expressed neuroendocrine markers. The presence of an intraductal papillary lesion with neuroendocrine differentiation suggests solid papillary carcinoma. Thus, this case suggests that intraductal papilloma could be a precursor of solid papillary carcinoma.

Bloody nipple discharge due to intraductal papilloma in an adolescent girl.

An early adolescent girl was referred to our breast surgery clinic with multiple right-sided breast masses and several months of unilateral bloody nipple discharge. MRI demonstrated multiple enhancing masses in the right breast with intrinsic hypertensive T1 signal of the ducts extending to the nipple. A biopsy showed partially sclerosed intraductal papillomas without atypia or malignancy. Following extensive counselling with the patient and her family, two palpable breast masses and a single central breast duct responsible for bloody nipple discharge were fully excised. Histopathological analysis showed unique overlapping features of resembling intraductal papilloma, nipple adenoma and fibroadenomas. The patient has had resolution of her bloody nipple discharge and excellent cosmetic outcomes post-surgery. Intraductal papilloma is rare in the adolescent population and the risk of concurrent and future malignancy is not well established. Thus, a tailored approach to the work-up and management of paediatric breast masses is essential.

Next Generation Sequencing in Vitellointestinal Duct Adenoma: Existence of Adenoma-Carcinoma Sequence or too Early to Predict?

Patent vitello-intestinal duct with adenoma is rare presentation. We report a case of a 1-month-old boy presenting with intermittent passage of stool and blood from the umbilicus since birth. On local examination polypoidal mass measuring 1×1 cm was seen protruding from umbilicus with faecal discharge. Ultrasound was performed which revealed a tubular hyperechoic structure, extending from umbilicus to part of small intestine measuring 30 ×30 mm and clinical diagnosis of patent vitello-intestinal duct was given, exploratory laparotomy, excision with umbilicoplasty done, and send for histopathological examination. On histopathological examination, patent vitello-intestinal duct adenoma was rendered and next generation sequencing (NGS) was performed revealing somatic mutation of KRAS (NM_033360.4; c.38G>A; p.Gly12Asp). To our knowledge, this is the first report of the adenoma in patent vitello-intestinal duct with NGS analysis. This case emphasizes the importance of thorough microscopic examination of resected patent vitello-intestinal duct and mutational analysis of the early lesions.

Ultrasound-Guided Vacuum-Assisted Excision to Treat Intraductal Papilloma.

BACKGROUND: To evaluate the value of ultrasound-guided vacuum-assisted excision (US-guided VAE) in the treatment of intraductal papillomas, including intraductal papillomas with atypical ductal hyperplasia (ADH), and to evaluate the lesion characteristic features affecting the local recurrence rate. MATERIALS AND METHODS: Between August 2011 and December 2020, 91 lesions of 91 patients underwent US-guided VAE and were diagnosed with intraductal papilloma with or without ADH. The recurrence rate of intraductal papilloma was evaluated on follow-up US. The lesion characteristic features were analyzed to identify the factors affecting the local recurrence rate. RESULTS: The local recurrence rate of intraductal papillomas removed by US-guided VAE was 7.7% (7/91), with the follow-up duration 12-92 months (37.4 ± 23.9 months). Of the 91 patients, five cases diagnosed as intraductal papilloma with ADH did not recur, with the follow-up time 12-47 months (26.4 ± 14.4 months). There were no malignant transformation in all 91 cases during the follow-up period. All 7 patients recurred 7-58 months (22.8 ± 19.2 months) after US-guided VAE. There were no significant differences between the non-recurrence and recurrence groups in terms of age, side, distance from nipple, lesion size, BI-RADS category, with ADH, or history of excision (p > 0.05). CONCLUSIONS: US-guided VAE is an effective method for the treatment of intraductal papilloma, including intraductal papilloma with ADH. It avoids invasive surgical excision, but regular follow-up is recommended to prevent recurrence or new onset due to multifocality. Any suspicious lesions during the follow-up should be actively treated.

Papillomatous breast lesions with atypical columnar cell features.

AIMS: Columnar cell lesions (CCLs) are recognised breast cancer precursor lesions. Intraductal papillomas are usually lined by benign (polyclonal) cells. Although papillomas with monoclonal lesions (atypical ductal hyperplasia (ADH)/ductal carcinoma in situ (DCIS)) have been described, CCLs have not been described in papillomas. METHODS: We present two papillary breast lesions lined by a single layer of luminal cells resembling atypical CCL/flat epithelial atypia (FEA). We compared these two lesions with 13 benign intraductal papillomas, and 2 papillomas with ADH/DCIS grade 1 features as controls were immunohistochemically stained for the oestrogen receptor alpha (oestrogen receptor) and progesterone receptors (PR), cytokeratin 5 (CK5) and cyclin D1. RESULTS: Oestrogen receptor/PR expression was variable, with areas with ≥85% hormone receptor positivity in both morphologically normal papillomas and papillomas with ADH. In ADH areas, CK5 expression was seen in ≤5% of cells while cyclin D1 expression was high (>60%). The two papillary lesions with FEA were 100% oestrogen receptor and 90% cyclin D1 positive, and low on PR/CK5. There was only one morphologically normal papilloma with similar areas of low CK5 (5%) and high cyclin D1 expression; in all other morphologically benign papillomas CK5 expression varied between 10% and 50% and cyclin D1 expression was ≤50%. The papillary lesion with FEA that could be tested showed 16q losses, the hallmark genetic change in low nuclear grade breast neoplasias, in contrast to nine morphologically benign papillomas that could be tested. CONCLUSION: We present two papillomatous breast lesions with atypical CCL morphology and 16q loss, for which we propose the term papillary FEA.

Intraductal Papillomas.

The most common manifestation of papillary breast disease is intraductal papilloma (IDP). As breast disease management becomes more refined, increasing attention has been directed at determining which IDPs require excision, and which can be monitored. This article will discuss the most common factors currently impacting personalized decision-making.

The effect of delay of excisional biopsy on upstage rate for atypical ductal hyperplasia, flat epithelial atypia, intraductal papilloma, and radial scar.

PURPOSE: When Core Needle Biopsy (CNB) demonstrates Atypical Ductal Hyperplasia (ADH), Flat Epithelial Atypia (FEA), Intraductal Papilloma (IDP), or Radial Scar/Complex Sclerosing Lesion (RS), excisional biopsy (EB) is often performed to rule out underlying malignancy with upstage rates (UR) ranging between 1 and 20%. The COVID-19 pandemic led to delayed EB for many patients. We sought to evaluate whether this delay was associated with higher UR. METHODS: We performed a retrospective analysis of women who underwent CNB and then EB for ADH, FEA, IDP, or RS between 2017 and 2021 using an IRB-approved repository. UR was evaluated by days between CNB and EB. RESULTS: 473 patients met inclusion. 55 were upstaged to cancer (11.6%). 178 patients had pure ADH on CNB and 37 were upstaged (20.8%). 50 patients had pure FEA and 3 were upstaged (6%). 132 had pure IDP and 7 were upstaged (5.3%). 98 had pure RS and 1 was upstaged (1%). 7/15 (46.7%) had a combination of diagnoses or diagnosis with palpable mass and were upstaged. Days between CNB and EB were < 60 for 275 patients (58.1%), 60-90 for 108 (22.8%), 91-120 for 43 (9.1%), and > 120 for 47 (9.9%). There was no significant difference in UR (10.9% for < 60, 14.8% for 60-90, 7% for 90-120, and 12.8% for > 120, p = 0.54). UR for ADH was clinically increased after 60 days (27.8 vs. 17.5%), but this did not reach statistical significance (p = 0.1). CONCLUSION: Surgical delay was not associated with an increased UR.

Upgrade rates of intraductal papilloma with and without atypia diagnosed on core needle biopsy and clinicopathologic predictors.

Surgical excision of breast intraductal papilloma (IDP) without atypia diagnosed on core needle biopsy (CNB) is controversial as the risk of upgrade to malignant lesions is not well established. This study investigates upgrade rates of benign and atypical IDP to ductal carcinoma in situ (DCIS) and invasive carcinoma (IC) and clinicopathologic predictors. We identified 556 cases of IDP diagnosed on CNB at a single institution from 2010 to 2020 after excluding patients with a history of breast carcinoma, ipsilateral high-risk lesion, radiologic/pathologic discordance, or less than 2 years of follow-up if no excision within 1 year. Of these, 97 biopsies were consistent with atypical IDP and 459 were benign IDP. Surgical excision was performed for 318 (57.2%), and the remaining 238 (42.8%) underwent active monitoring. The upgrade rate for IDP without atypia was 2/225 (0.9%; 1 DCIS and 1 IC). Of 93 surgically excised atypical IDPs, 19 (20.4%) upgraded (14 DCIS and 5 IC). Of 238 nonexcised IDPs followed clinically (range, 24-140 months, mean 60 months), there was no subsequent breast cancer diagnosed at the IDP site on follow-up. Mean age of patients was 56 yr ± 12.6 SD without upgrade, 63 yr ± 10.6 SD (P = .027) with DCIS, and 61 yr ± 10.8 SD (P = .35) with IC. Atypical IDP was more likely to upgrade if biopsied by stereotactic guidance (8/19, 42.1% P = .035). At our institution, we had an exceedingly low upgrade rate for benign IDP. Overall, patients with upgrade to DCIS were older. For atypical IDP, upgrade was seen in higher proportions of stereotactic biopsies.

Papillary lesions of the breast - review and practical issues.

Papillary lesions of the breast represent a heterogeneous group of neoplasm featuring fibrovascular cores covered by epithelial cells with or without intervening myoepithelial cells. According to the World Health Organization classification of breast tumors, papillary lesions of the breast are further classified into intraductal papilloma (including intraductal papilloma with atypical ductal hyperplasia /ductal carcinoma in situ), papillary ductal carcinoma in situ, encapsulated papillary carcinoma, solid papillary carcinoma (in situ and invasive) and invasive papillary carcinoma. The overlapping morphological features and immunohistochemical profiles make accurate diagnosis of breast papillary lesion a challenge for pathologists. In this review, the morphological and relevant immunohistochemical features of papillary lesions are discussed, with further emphasis on some commonly encountered practical diagnostic issues. A simple diagnostic algorithm will be established. The relevant molecular characteristics will be discussed as well.

Radiologic and Pathologic Findings of Axillary Intraductal Papilloma Arising in Accessory Breast Tissue: A Case Report and Literature Review.

INTRODUCTION: This is a rare case report of axillary intraductal papilloma arising in accessory breast tissue. CASE PRESENTATION: A 49-year-old woman presented to our clinic with a palpable right axillary mass that had first appeared 6 months earlier. Mammography and ultrasonography of the right axilla revealed an ovoid mass surrounding accessory breast tissue. Ultrasound-guided 14-G core-needle biopsy was performed and pathologically revealed intraductal papilloma without atypia. CONCLUSION: Since ectopic breast tissue is affected by the same pathologic processes as normal breast tissue, a core-needle biopsy can be used to identify the suspicious lesions in axillary breast tissue.

A retrospective study evaluating outcomes of surgical excision versus radiologic follow-up of benign breast papillomas without atypia.

BACKGROUND: There is uncertainty whether benign breast papillomas without atypia (BP) can be followed by imaging or require surgical resection. METHODS: A single-center, retrospective cohort study of patients diagnosed with BP (2011-2021) to determine the upgrade rate on surgery, and factors associated with surgical intervention and upgrade. RESULTS: 139 BPs were included. 27(19.4%) had upfront surgery; 112(80.6%) had imaging follow-up. The upfront surgery group had higher rates of pre-excision nipple inversion (n = 2(8.3%)vs.n = 0(0%),p = 0.003). In the imaging group, the median follow-up was 3.8years, and 9 had subsequent resection. Upgrade rate was 5.8%(8/139). Of all BPs undergoing surgery (n = 36), patients ≥60years (75.0%vs.25.0%,p = 0.049) or with family history of breast cancer (87.5%vs.48.1%,p = 0.048) were more likely to have upgrade. CONCLUSIONS: Despite a low number of events, this study supports radiologic follow-up of BP except in patients ≥60 years or with family history of breast cancer, adding to the growing body of evidence supporting watchful waiting of BPs.

Late-onset Proteus syndrome with cerebriform connective tissue nevus and subsequent development of intraductal papilloma.

Proteus syndrome (PS) is a rare segmental overgrowth disorder caused by a mosaic activating variant in AKT1. The features of PS are often not present at birth but develop during the first few years of life. We describe a 55-year-old female, whose first symptom of overgrowth, a cerebriform connective tissue nevus, occurred at 19 years of age. We report the identification of the AKT1 c.49G > A p.(Glu17Lys) variant in this progressive lesion, the bony overgrowth, and recurrence after surgical intervention. In the sixth decade of life, this individual developed intraductal papillomas within her right breast which were confirmed to contain the same activating AKT1 variant as the connective tissue nevus. While similar neoplasms have been described in an individual with Proteus syndrome, none has been evaluated for the presence of the AKT1 variant. The tumor also contained two likely pathogenic variants in PIK3R1, c.1392_1403dupTAGATTATATGA p.(Asp464_Tyr467dup) and c.1728_1730delGAG p.(Arg577del). The finding of additional genetic variation putatively affecting the PI3K/AKT pathway in the neoplastic tissue may provide preliminary evidence of a molecular mechanism for tumorigenesis in PS. The late onset of symptoms and molecular characterization of the breast tumor expand the clinical spectrum of this rare disorder.

Breast Density Lacks Influence on Upgrade Rates to High Risk Lesions and Cancer Among Proliferative Breast Lesion Excisions.

INTRODUCTION: Breast density is an independent risk factor for the development of breast cancer. We assessed if upgrade rates to high-risk lesions and cancer were influenced by density when evaluating proliferative complex sclerosing lesions and intraductal papillomas. METHODS: This is a retrospective single institution study. We evaluated 168 women aged 18-86 who received a core needle biopsy revealing a breast proliferative lesion of complex sclerosing lesion (CSL) or intraductal papilloma. We analyzed the upgrade rate to high-risk atypia (HRL) and cancer. Subgroup analysis based on age and breast density was performed. RESULTS: The patient collective was well balanced-51% had dense breasts and 42% were under 50 years old. Half were diagnosed with papilloma based on CNB and the other half with CSL. For those proliferative lesions without atypia, the upgrade rate to cancer was 1.6%. CNB showed concomitant HRL in 23% of patients with non-dense breasts and in 22% with dense tissue. In 24 cases, the pathology was considered an upgrade by showing either a not prior noted HRL or carcinoma. Most patients with upgrade following surgical excision were over 50 years old. Dense breasts did not show a higher risk of upgrade following surgical excision (P = .975). CONCLUSION: Our data did not reveal a difference between upgrade rates of proliferative lesions excised in dense and non-dense breasts. Further evaluation is warranted to establish whether density should be considered as a meaningful factor in excision vs observation of CSL and papillomas.