Papillary lesions of the breast: a review

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.

Virtual Biopsy by Using Artificial Intelligence-based Multimodal Modeling of Binational Mammography Data

Background Computational models based on artificial intelligence (AI) are increasingly used to diagnose malignant breast lesions. However, assessment from radiologic images of the specific pathologic lesion subtypes, as detailed in the results of biopsy procedures, remains a challenge. Purpose To develop an AI-based model to identify breast lesion subtypes with mammograms and linked electronic health records labeled with histopathologic information. Materials and Methods In this retrospective study, 26 569 images were collected in 9234 women who underwent digital mammography to pretrain the algorithms. The training data included individuals who had at least 1 year of clinical and imaging history followed by biopsy-based histopathologic diagnosis from March 2013 to November 2018. A model that combined convolutional neural networks with supervised learning algorithms was independently trained to make breast lesion predictions with data from 2120 women in Israel and 1642 women in the United States. Results were reported using the area under the receiver operating characteristic curve (AUC) with the 95% DeLong approach to estimate CIs. Significance was tested with bootstrapping. Results The Israeli model was validated in 456 women and tested in 441 women (mean age, 51 years ± 11 [SD]). The U.S. model was validated in 350 women and tested in 344 women (mean age, 60 years ± 12). For predicting malignancy in the test sets (consisting of 220 Israeli patient examinations and 126 U.S. patient examinations with ductal carcinoma in situ or invasive cancer), the algorithms obtained an AUC of 0.88 (95% CI: 0.85, 0.91) and 0.80 (95% CI: 0.74, 0.85) for Israeli and U.S. patients, respectively (P = .006). These results may not hold for other cohorts of patients, and generalizability across populations should be further investigated. Conclusion The results offer supporting evidence that artificial intelligence applied to clinical and mammographic images can identify breast lesion subtypes when the data are sufficiently large, which may help assess diagnostic workflow and reduce biopsy sampling errors. Published under a CC BY 4.0 license. Online supplemental material is available for this article.

An intriguing journey of encapsulated apocrine papillary carcinoma of the breast

Background

Encapsulated Apocrine Papillary Carcinoma (EAPC) of the breast are very rare tumors. They usually present as a cystic mass with mural nodule in women aged 44–84 years. Affected patients may be asymptomatic or complain of breast swelling, or nipple discharge. Mammographic features are nonspecific. The tumor appears as a high-density round or oval mass with circumscribed or spiculated margins on mammography. On Ultrasonography (US) a classical lesion appears as predominantly cystic mass with intracystic solid papillary projections and area of vascularity within it. Contrast Enhanced Breast MRI helps to further characterize the lesion by showing intense contrast enhancement in early phase along with washout curve. Histological features of these tumors are similar to those of classical encapsulated papillary neoplasm, in that myoepithelial cells are absent within the papillary structures and at the periphery of the cyst. They show variable degree of cytological atypia and mitotic activity. Such tumors consist of abundant granular eosinophilic cytoplasm and large nuclei with prominent nucleoli and are androgen receptor positive. However, a multidisciplinary approach is crucial for diagnosis and tissue histology is essential to suitably formulate treatment guidelines. Surgical excision is the preferred treating option for these tumors. Little consensus is available about local radiation and adjuvant therapy for the treatment of such tumors, yet they have been reported to have good prognosis.

Case presentation

This rare case report describes the intriguing journey towards the diagnosis of an encapsulated intracystic apocrine papillary carcinoma in a 52-year-old premenopausal female who presented with palpable breast swelling in left breast. The patient underwent mammography, breast ultrasound and breast MRI concluding it to be a BIRADS 4A lesion. Then the patient was subjected to trucut core biopsy and finally surgical excision was performed. On Histopathology this lesion was diagnosed as encapsulated apocrine papillary carcinoma with androgen receptor positivity and triple negative hormonal status. At present patient is on regular follow-up.

Conclusions

Encapsulated intracystic apocrine papillary carcinoma has a favorable prognosis with low recurrence rate and excellent long-term survival regardless of its invasive nature. Therefore, we present this rare entity to highlight the importance of radiological and histopathology findings in its diagnosis.

Encapsulated Papillary Carcinoma: A Rare Case Report and Its Imaging Features

Papillary lesions in the breasts are uncommon and have a wide range of pathologies. Due to diverse non-specific findings radiologically and histologically, papillary neoplasms are always a challenge to radiologists. Encapsulated papillary carcinomas (EPCs) of the breast, also known as intracystic papillary carcinomas, are a subgroup of intraductal papillary lesions of the breast. We present a case of a painless right breast lump with the aim to describe a rare encapsulated papillary carcinoma and its imaging features.

Factors associated with upgrade, malignant upgrade, and subsequent breast cancer occurrence of papillary breast lesions diagnosed on core needle biopsy

AIM

In this study, we analyzed the upgrade rate and associated factors for upgrade, malignant upgrade, and subsequent breast cancer occurrence of papillary breast lesions diagnosed on core needle biopsy (CNB).

METHODS

One hundred sixty-nine patients who underwent surgery for the treatment of papillary breast lesions diagnosed on CNB were included in this study. Medical records including radiological and pathological reports were retrospectively reviewed.

RESULTS

The overall upgrade rate was 29.6%, and upgrade rate to malignancy was 16.6%. Age over 45 years, preoperative tumor size ≥0.7 cm on breast ultrasound, pathologic tumor size ≥0.4 cm, breast imaging reporting and data system (BIRADS) category 4b or 4c, and personal history of breast cancer were associated with upgrade. In addition, age over 45 years, preoperative tumor size ≥0.9 cm, pathologic tumor size ≥0.6 cm, atypia in CNB, and BIRADS category 4b or 4c were associated with malignancy. The risk of subsequent breast cancer occurrence was increased in preoperative tumor size ≥0.8 cm, pathologic tumor size ≥0.5 cm, multiple and recurrent lesions.

CONCLUSION

Our study showed high upgrade rate of papillary breast lesions diagnosed on CNB. Our findings suggest that surgical excision is recommended for papillary breast lesions diagnosed on CNB in selected patients.

Breast carcinomas of low malignant potential

Some breast carcinomas have a very low likelihood of metastasis to regional lymph nodes and distant sites and may be considered carcinomas of low malignant potential. In this article, we review the clinical, pathologic, immunophenotypic, and molecular features of selected breast carcinomas of low malignant potential including low-grade adenosquamous carcinoma, fibromatosis-like metaplastic carcinoma, encapsulated papillary carcinoma, solid papillary carcinoma, and tall cell carcinoma with reversed polarity.

Papillary breast lesions detected using conventional ultrasound and contrast-enhanced ultrasound: Imaging characteristics and associations with malignancy

OBJECTIVE

This study aimed to evaluate the imaging features of papillary breast lesions detected using conventional ultrasonography (US) and contrast-enhanced ultrasound (CEUS) and to correlate the pathological results. Furthermore, the diagnostic efficiencies of these imaging features to predict the malignancy potential of papillary lesions were explored.

METHODS

The findings of the conventional US and CEUS of 74 consecutive papillary breast lesions were assessed retrospectively. The obtained data were analyzed using univariate and multivariate logistic regressions to evaluate the ability of each parameter and combined parameters in distinguishing the benign and atypical or malignant papillary lesions.

RESULTS

Among the imaging features of breast papillary lesions on conventional US and CEUS, two sonographic features (lesion size ≥1 cm and not circumscribed margin) on conventional US and four enhancement features (irregular enhancement, heterogeneous enhancement, enlargement of scope, and perfusion defect) on CEUS were found to be significantly different between the benign and atypical or malignant papillary lesions (P < 0.05). A multivariate logistic regression analysis further showed that only heterogeneous enhancement and enlarged enhancement scope were associated with malignancy. The sensitivity and specificity of heterogeneous enhancement, enlarged enhancement scope, and combined analysis for predicting atypical and malignant papillary lesions were 78.6 % and 39.1 %, 75 % and 37 %, and 75 % and 82.6 %, respectively. The combination of enhancement homogeneity and enhancement scope improved the diagnostic accuracy (AUC = 0.875).

CONCLUSIONS

The results suggested that the imaging features on conventional US and CEUS could help in identifying benign and malignant papillary lesions and predict their malignancy potential.

Analysis of 612 Benign Papillomas Diagnosed At Core Biopsy: Rate of Upgrade to Malignancy, Factors Associated with Upgrade, and A Proposal For Selective Surgical Excision

Background: Despite numerous published studies, management of benign papillomas without atypia remains controversial. Objective: To determine the malignancy upgrade rate of benign papillomas, identify risk factors for upgrade, and formulate criteria for selective surgery. Methods: This retrospective study included benign papillomas without atypia diagnosed on percutaneous biopsy between 12/01/2000 and 12/31/2019. Papillomas that did not undergo surgical excision or at least 2 years of imaging and/or clinical follow-up were excluded. Clinical, imaging, and histopathologic features were extracted from the electronic medical record. Features associated with upgrade to malignancy were identified. Multivariable logistic regression was performed. Results: The study included 612 benign papillomas in 543 women (mean age 54.5 ± 12.1 years); 466 papillomas were excised, and 146 underwent imaging/clinical surveillance. The upgrade rate to malignancy was 2.3% (14/612). Upgrade rate was associated (p<.05) with radiology-pathology correlation (50.0% if discordant vs 2.1% if concordant), patient age (5.6% for age ≥60 vs 0.7% for age <60), presenting symptoms (6.7% if palpable mass or pathologic nipple discharge vs 1.3% if no symptoms), and lesion size (7.3% if ≥10 mm vs 0.6% if <10 mm). Three of 14 upgraded papillomas were associated with ≥4 metachronous or concurrent peripheral papillomas. No incidental papilloma or papilloma reported as completely excised on core biopsy histopathologic analysis was upgraded. A predictive model combining radiology-pathology discordance, symptoms (palpable mass or nipple discharge), age ≥60, size ≥10 mm, and presence of ≥4 metachronous or concurrent peripheral papillomas achieved AUC 0.91, sensitivity 79%, and specificity 89% for upgrade. Selective surgery based on presence of any of these five factors, while excluding from surgery incidental papillomas and papillomas reported as completely excised on histopathology, would spare 294 of 612 lesions from routine excision, while identifying all 14 upgraded lesions. Conclusion: Benign non-atypical papillomas have a low malignancy upgrade rate; routine surgical excision may not be necessary. Selective excision is recommended for lesions satisfying any of the 5 criteria. Incidental papillomas or papillomas completely excised on histopathology may undergo imaging follow-up. Clinical Impact: The proposed criteria for selective surgery of benign papillomas on core biopsy would reduce surgeries without delaying diagnosis of malignancy.

Encapsulated papillary carcinoma with and without frank invasion: Comparison of clinicopathologic features and role of axillary staging

To investigate clinical and pathologic features of encapsulated papillary carcinomas (EPCs) that may be associated with invasive disease and characterize the axillary staging practices for EPCs at our institution. A pathology database search for cases containing "papillary carcinoma" was performed. Slides were reviewed by two pathologists. Clinicopathological features and axillary staging practices of EPCs with and without invasion were compared. Twenty-five cases of EPCs were identified. Fifteen cases contained a frank invasive tumor (60%), which were all pT1 (0.7 ± 0.56 cm), and the majority were ER-positive, HER2-negative, low-grade IDC-NST. Seventeen patients underwent sentinel lymph node biopsies (SLNB). No nodal metastases were identified. Follow-up was available for 24 patients (mean = 39 ± 29 months); 23 had no NED. Patients that presented with a self-palpated mass (versus screening) were more likely to have an invasive component; however, no pathologic or radiologic features differentiated EPCs with and without frank invasion. Pathologic and radiologic characteristics did not differentiate EPCs with and without frank invasion. EPCs have an excellent prognosis supported by the notable disease-free survival and negative nodal status in our cohort, which supports the notion that patients with EPCs may forgo axillary staging.

Clinicopathologic Characteristics and Prognosis of Invasive Papillary Carcinoma of the Breast

BACKGROUND

Invasive papillary carcinoma (IPC) of the breast is thought to carry a more favorable prognosis than invasive ductal carcinoma (IDC). The aim of this study is to investigate the clinicopathological characteristics between IPC and IDC and their prognosis using a large nationwide data set.

METHODS

Female patients diagnosed with malignant IPC and IDC between 2005 and 2014 were analyzed. Patients with incomplete survival data, stage 0/IV, unknown stage, or recurrent disease were excluded. Five-year overall survival was compared between IPC and IDC.

RESULTS

Among 308,426 patients, 1147 had IPC and 307,279 had IDC. IPC presented more in older postmenopausal women, black Americans, and people who had government insurance. IPC had larger tumor size, lower-grade, and earlier-stage disease, less node-positive disease, higher hormone positivity, and lower human epidermal growth factor receptor 2 amplification. Adjuvant radiation and chemotherapy rates were lower in IPC than those in IDC. IPC had a similar 5-year overall survival as compared with IDC overall (86.8% versus 88.7%) (P = 0.06). Age, pathologic stage, and radiation treatment were shown to be independent prognostic factors of IPC.

CONCLUSIONS

IPC has a similar prognosis as IDC, suggesting that these patients should follow the same treatment protocols.

Encapsulated Papillary Carcinoma of the Breast: Imaging Features with Histopathologic Correlation

Encapsulated papillary carcinoma (EPC) is a rare, clinically indolent breast malignancy most common in postmenopausal women. Absence of myoepithelial cells at the periphery is a characteristic feature. Mammographically, EPC typically presents as a mostly circumscribed, noncalcified, dense mass that can have focally indistinct margins when there is associated frank invasive carcinoma. Ultrasound shows a circumscribed solid or complex cystic and solid mass, and occasional hemorrhage in the cystic component may produce a fluid-debris level; the solid components typically show intense washout enhancement on MRI. Color Doppler may demonstrate a prominent vascular pedicle and blood flow within solid papillary fronds. Encapsulated papillary carcinoma can exist in pure form; however, EPC is often associated with conventional ductal carcinoma in-situ and/or invasive ductal carcinoma, no special type. Adjacent in-situ and invasive disease may be only focally present at the periphery of EPC and potentially unsampled at core-needle biopsy. In order to facilitate diagnosis, the mass wall should be included on core-needle biopsy, which will show absence of myoepithelial markers. Staging and prognosis are determined by any associated frankly invasive component, with usually excellent long-term survival and rare distant metastases.

Pathology of breast papillary neoplasms: Community hospital experience

In this study, 550 breast papillary neoplasms collected in a community hospital over more than ten years were reviewed and analyzed. This included 457 intraductal papillomas, 53 papillary carcinomas, 35 papillary DCIS and five invasive papillary carcinomas. The diagnostic rate of papillary neoplasms increased over time, likely due to better recognition by pathologists. Intraductal papillomas occurred most frequently in the upper outer quadrants and contained ADH/DCIS in 19% of cases. A total of 28% of non-incidental papillomas were associated with ADH/DCIS, and 29% of patients with papillomas had ADH/DCIS in adjacent tissue; nearly half of papillomas that were > 1 cm in size contained ADH/DCIS in the papilloma or adjacent to it. No single feature could predict an upgrade on excision for non-atypical intraductal papillomas diagnosed on core biopsy. There was no significant difference in the association of ADH/DCIS with central or peripheral papillomas. The overall upgrade rate of non-atypical intraductal papillomas to DCIS on excision was 2%, which justifies the conservative management of non-atypical sub-centimeter lesions. Papillary carcinomas occurred in older than intraductal papilloma patients and were most frequent in the upper quadrants. Although classically devoid of a myoepithelial cell layer, papillary carcinomas may contain some residual or even an ample myoepithelial cell layer in the papillae. An association between papillary carcinoma and conventional invasive carcinoma was found in 40% of EPCs and 89% of SPCs. Papillary DCIS was usually low- or intermediate-grade. The presence of a myoepithelial cell layer in the papillae was not inconsistent with this diagnosis. Invasive papillary carcinoma may have two histologic patterns: papillary and cribriform.

Benign Breast Disease in Women

BACKGROUND

Most clinical breast changes in women are benign; in only 3% to 6% of cases are they due to breast cancer. How- ever, there is a lack of up-to-date, evidence-based treatment recommendations for the various benign differential diagnoses.

METHODS

Selective literature search of PubMed from 1985 to May 2019, including current national (AWMF, Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften [Association of Scientific Medical Societies in Germany]) and inter- national guidelines.

RESULTS

Mastalgia and fibrocystic changes are common (around 50% of all women over the age of 30). Fibroadenomas occur in 25% of women; they are the most common benign tumors of the breast and do not require treatment. With most benign breast changes the risk of dedifferentiation is very low. However, it is important in the differential diagnosis to distinguish between such benign changes and breast cancer or changes that carry a risk of malignancy. Complex cysts, for example, carry a risk of malig- nancy of 23% to 31%, papillary lesions 16% , and radial scars 7%. Where there is doubt, histological confirmation should be sought by means of percutaneous biopsy.

CONCLUSION

Benign breast changes can be definitively distinguished from malignant lesions through the selective use of avail- able diagnostic investigations and interdisciplinary collaboration. When lesions of uncertain malignant potential are found (B3 in the biopsy classification), complete excision is indicated. Prospective studies on the early diagnosis of breast cancer in lesions carrying a risk of malignancy are desirable.

Papillary breast cancer: A retrospective single-centre clinical study

Papillary carcinoma (PC) of the breast is a rare malignancy that accounts for 0.5%-1% of breast cancers. PC remains an understudied cancer, and we still require further information on its behaviour, staging and management. In particular, a significant proportion of PC cases still undergo sentinel lymph node biopsy without clear empirical justification. In the present study, we provide a valuable cohort of 44 PC patients and examine the clinicopathological features and outcome of loco-regional staging. Our results provide important insights into the behaviour of PC and suggest SLNB may be spared in this condition. Crucially, we show only one histologically confirmed PC case had evidence of nodal metastasis. In addition, up to 5 years postsurgery, no patient in our cohort died from their cancer. Together, our results support further work in the utility of SLNB in PC and highlight the favourable prognosis of this tumour. We propose SLNB should not be routinely indicated for patients with PC treated with breast conservation, and future studies should aim to incorporate prospective data to help inform optimal management of PC.

Core needle biopsy of benign, borderline and in-situ problematic lesions of the breast: Diagnosis, differential diagnosis and immunohistochemistry

Core needle biopsy (CNB) is the most common sampling technique for the histologic evaluation of breast abnormalities. Diagnosing benign proliferative, borderline and some in-situ lesions in CNB is challenging and subject to a significant degree of interobserver variability. In addition, due to the inherent limitations of CNB, "upgrading" to a more significant pathology at excision is an important consideration for some lesions. Pathologists carry a major responsibility in patient diagnosis, risk stratification and management. Familiarity with the histologic features and the clinical significance of these common and problematic lesions encountered in CNB is necessary for adequate treatment and patient follow-up. This review will focus on benign, atypical and in-situ epithelial proliferations, papillary lesions, radial sclerosing lesions, adenosis and cellular fibroepithelial lesions. Highlights of histologic features, useful strategies for accurate diagnosis, basic immunohistochemistry and management will be presented.

Prognostic Factors, Treatment, and Outcomes in Early Stage, Invasive Papillary Breast Cancer: A SEER Investigation of Less Aggressive Treatment in a Favorable Histology

OBJECTIVES

Invasive papillary breast cancer (IPBCA) represents 0.5% of invasive BCA, and is thought to carry a favorable prognosis. This population-based study reports on prognostic factors, treatment, and outcomes of early-stage IPBCA to explore whether there is any evidence to support less aggressive treatment.

MATERIALS AND METHODS

IPBCA cases from 1990 to 2009 of the recent Surveillance, Epidemiology, and End Results were analyzed. Inclusion criteria included patients with stage T1-2, N0 IPBCA. Univariate and multivariate analyses were performed using the variables of treatment, stage, race, hormone receptor status, grade (G1-3), and age. Treatment modalities included lumpectomy alone (LA), lumpectomy with radiation treatment (LRT), and mastectomy alone (MA).

RESULTS

Among 10,485 patients, median follow-up was 56 months. Five and 10-year overall survival (OS) were 93.1% and 76.8%, respectively. Patients treated with LRT had superior mean OS 16.8 versus 14.9 years for MA (P=0.0004) and 14.2 years for LA (P=0.0003). Improved OS also correlated with lower histologic grade (P<0.0001), lower T-stage (P<0.0001), and younger age (P<0.0001). Black patients had the worst OS (12.7 y, P<0.0001).

CONCLUSIONS

LRT is associated with superior OS for early-stage invasive papillary BCA patients, when compared with LA or MA in this population-based study. The findings support the standard of care breast conservation approach for patients with invasive papillary BCA. Other prognostic factors associated with worse OS include increased age, higher T-stage, higher histologic grade, and black race.

Magnetic resonance imaging features for differentiating breast papilloma with high-risk or malignant lesions from benign papilloma: a retrospective study on 158 patients

Background

Benign breast papilloma is currently managed with conservative management with close observation. In contrast, papilloma with high-risk or malignant lesions warrants surgical excision. The purpose of our study was to investigate magnetic resonance imaging (MRI) features of breast papilloma and to identify imaging diagnostic indicators for papilloma with high-risk or malignant lesions.

Methods

MRI features of 175 surgically confirmed papillomas on 158 patients were retrospectively reviewed. The 175 cases included 132 cases of benign papilloma and 43 cases of papilloma with high-risk or malignant lesions. The MRI features of these lesions were classified into three types: mass, non-mass enhancement (NME), and occult lesion. The occult lesion was defined as the presence of only ductal dilation without any enhanced lesions on MRI. For a mass lesion, the mixed mass-NME lesion was considered if linear, segmental or regional enhanced lesion was found adjacent to the mass. Clinical and MRI features were compared by univariate and multivariate analysis between the benign papilloma and the papilloma with high-risk or malignant lesions.

Results

Multivariate logistic regression analysis demonstrated that clinical characteristics including being or older than 50 years (odds ratio [OR] = 4.506), having bloody nipple discharge (OR = 4.499), and concurrent breast cancer (OR = 5.083) were significant indicators for papilloma with high-risk or malignant lesions. On MRI, most papillomas presented as mass (n = 135, 77.1%), and fewer as NME (n = 37, 21.1%) and occult lesion (n = 3, 1.7%). For the mass lesion, the logistic regression analysis demonstrated that a mass size exceeding 10 mm (OR = 2.956) and mixed mass-NME lesion (OR = 4.143) were independent risk indicators for a papilloma with high-risk or malignant lesions. For the NME lesion, the segmental or regional distribution was more commonly observed in the papilloma with high-risk or malignant lesions (61.5%) than the benign papilloma (12.5%) (P = 0.006). All the cases of occult lesions were benign papillomas.

Conclusions

MRI features including a mass size exceeding 10 mm, mixed mass-NME lesion, and NMEs with segmental or regional distribution indicate a papilloma with high-risk or malignant lesions.

Apocrine papillary lesion: comparison of pathological findings from 22 years previously and the present

Apocrine papillary lesion (APL) is difficult to diagnose as benign or malignant. We experienced an APL remaining in the body for 22 years. We present a case of a 71-year-old woman who had undergone excisional biopsy 22 years previously at the first hospital that she visited. 1 year previously, she had undergone fine-needle aspiration cytology at a second hospital, and the lesion was diagnosed as potentially malignant. She underwent core-needle biopsy at a third hospital, but whether the lesion was benign or malignant could not be definitively diagnosed. We performed right mastectomy and sentinel lymph-node biopsy, because her tumor was suspected to be malignant based on imaging means, and malignancy could not be ruled out on either biopsy or cytology. The histopathological diagnosis was tiny foci of apocrine proliferative lesion with massive hemorrhagic necrosis and no tumor metastasis in two sentinel lymph nodes. Retrospectively, we compared all of the patient's previous specimens with the present ones, and applied the recent pathological diagnostic criteria. Although the biopsy specimen excised 22 years ago suggested an encapsulated apocrine papillary carcinoma or a papilloma with apocrine ductal carcinoma in situ, neither infiltration nor metastasis has occurred. Furthermore, neither the pathological findings nor the clinical behavior has changed over time.

Encapsulated Papillary Carcinoma in A Man with Gynecomastia: Ultrasonography, Mammography and Magnetic Resonance Imaging Features with Pathologic Correlation

Male breast cancer is an uncommon disease that constitutes 1% of all breast cancers and encapsulated papillary carcinoma (EPC) is a rare subtype of malignant male diseases. Gynecomastia is the most common disease of the male breast. We report a 63-year-old male patient with EPC accompanied by gynecomastia that was diagnosed and treated at our breast center. Mammography showed an oval-shaped dense mass with circumscribed margins on the ground of nodular gynecomastia. On ultrasonographic exam, we saw a well-circumscribed complex mass with a solid component which was vascular on Doppler ultrasonography. Magnetic resonance imaging revealed a complex cystic mass containing solid components. Dynamic images showed enhancement of the cystic mass wall and mural components. Tumor stage was evaluated as T2N0. The lesion's histologic examination and immunohistochemical analysis by showing no myoepithelial layer revealed an encapsulated papillary carcinoma. To our knowledge, this is the first case report which describes MR imaging findings of male breast encapsulated papillary cancer.

Core Needle Biopsy of the Breast: An Evaluation of Contemporary Data

Benign and atypical lesions associated with breast cancer risk are often encountered in core needle biopsies (CNBs) of the breast. For these lesions, the rate of "upgrade" to carcinoma in excision specimens varies widely in the literature. Many CNB studies are limited by a lack of radiological-pathological correlation, consistent criteria for excision, and clinical follow-up for patients who forego excision. This article highlights contemporary diagnostic criteria and outcome data that would support an evidence-based approach to the management of these nonmalignant lesions of the breast diagnosed on CNB.

Mutational Analysis of AKT1 and PIK3CA in Intraductal Papillomas of the Breast with Special Reference to Cellular Components

The pathologic feature of intraductal papillomas is defined as a papillary structure composed of a fibrovascular stromal core lined by luminal epithelial cells and myoepithelial cells. We used droplet digital PCR for the mutational analysis of AKT1 (E17K) and PIK3CA (H1047R, E542K, and E545K) in 60 papillomas. AKT1 and PIK3CA mutations were detected in 12 (20%) and 17 (28%) of the papillomas, respectively. In five tumors harboring mutations, mutational analysis of AKT1 or PIK3CA was performed separately using luminal epithelial cells and myoepithelial cells sorted using anti-cytokeratin 19 antibody and anti-α smooth muscle actin antibody. The two types of cells from a given papilloma had the identical mutation. Three patients with the PIK3CA mutation-positive papilloma developed breast cancers at the resection site of the papilloma, but none of these subsequent breast cancers had the PIK3CA mutation. These results indicate that a papilloma stems from a bipotent progenitor cell that contains the AKT1 or PIK3CA mutation and proliferates and differentiates to form the papilloma. Papilloma can be a risk factor for developing breast cancer but is unlikely to be its obligate precursor.

Update on Immunohistochemical Analysis in Breast Lesions

CONTEXT

- The utility of immunohistochemistry (IHC) in breast lesions needs to be updated with exceptions among these lesions. Biomarker studies with IHC in triple-negative breast carcinoma may help develop targeted therapies for this aggressive breast cancer. The distinction of metastatic lung adenocarcinoma to the breast and invasive breast carcinoma has significant prognostic and therapeutic implications. The determination can be challenging because both primary tumors can express estrogen receptor and/or HER2 by IHC, creating a diagnostic dilemma.

OBJECTIVES

- To provide a practical update on the use of IHC markers in differential diagnoses in breast lesions, including benign, atypical, precancerous, and malignant tumors; to highlight recently published research findings on novel IHC markers in triple-negative breast carcinoma cases; and to reinforce the importance of IHC use as an ancillary tool in distinguishing metastatic lung adenocarcinoma to the breast from primary breast carcinoma using real case examples.

DATA SOURCES

- PubMed (US National Library of Medicine, Bethesda, Maryland) literature review and authors' research data and personal experiences were used in this review.

CONCLUSIONS

- Immunohistochemistry has an important role in making differential diagnoses in breast lesions in morphologically equivocal settings; recognizing IHC expression status in the exceptions among these lesions will aid in the correct diagnosis of challenging breast cases. Studies suggest that androgen receptor, p16, p53, GATA3, and PELP1 may have potential diagnostic, prognostic, and predictive value in triple-negative breast carcinoma cases; these findings may provide insight and a greater understanding of the tumor biology in triple-negative breast carcinomas. In distinguishing metastatic estrogen receptor-positive or HER2⁺ lung adenocarcinoma to the breast from primary breast carcinoma, napsin A, TTF-1, and GATA3 comprise a useful IHC panel.

Breast Tumor Resembling Tall Cell Variant of Papillary Thyroid Carcinoma: A Solid Papillary Neoplasm With Characteristic Immunohistochemical Profile and Few Recurrent Mutations

OBJECTIVES

Breast tumor resembling tall cell variant of papillary thyroid carcinoma (BTRPTC) is a rare breast lesion that is unrelated to thyroid carcinoma. Morphologically, it shows a solid papillary lesion with bland cytology, eosinophilic/amphophilic secretions, nuclear grooves, reversal of nuclear polarity (recently described), and nuclear inclusions. Clinical course is often uneventful with few exceptions reported in the literature. Herein, we report three additional cases.

METHODS

Immunohistochemical staining and next-generation sequencing was performed on all three cases.

RESULTS

The lesional cells on all cases were positive for cytokeratin 5 and S100, with weak expression/lack of estrogen receptor. No staining was observed for myoepithelial markers (p63 and myosin heavy chain) around the lesion. IDH2 mutations were identified in two cases at nucleotide 172 (cases 1 and 3). ATM gene mutation was identified in cases 2 and 3 and PIK3CA mutation in case 3. All patients are currently without disease.

CONCLUSIONS

BTRPTC is a slow-growing neoplastic lesion that needs to be distinguished from other papillary lesions for optimizing therapy.

Pathological criteria and practical issues in papillary lesions of the breast - a review

Papillary lesions of the breast include a broad spectrum of lesions, ranging from benign papilloma, papilloma with atypical ductal hyperplasia (ADH) or ductal carcinoma in situ (DCIS) to papillary carcinoma. The accurate diagnosis of mammary papillary lesions is a challenge for pathologists, owing to the overlapping features among these lesions. In this review, some of the diagnostic criteria of papillary lesions are discussed, with special emphasis on some key morphological features, namely fibrovascular cores, epithelial proliferation in a solid pattern, intraductal papilloma complicated by ADH or DCIS, and invasion and its mimics. The roles of immunohistochemistry, and the interpretation of myoepithelial cell markers, hormone receptors, and high molecular weight cytokeratin, are addressed. Finally, novel biomarkers and genetic aberrations in papillary lesions are summarized.

Intracystic Papillary Carcinoma in a Man with Gynecomastia

Male breast cancer is a rare disease in the male breast whereas gynecomastia is quite common. An elevation of the estrogen-to-androgen ratio increases the risk of both of these diseases. However, a connection between gynecomastia and subsequent breast cancer development is controversial and unclear. Imaging studies including mammography and ultrasound provide valuable information in leading to a correct diagnosis. Traditionally, intracystic papillary carcinoma, also known as encapsulated papillary carcinoma, has been considered a form of ductal carcinoma in situ. Recent immunohistochemical studies, demonstrating an absence of myothelium, in many cases would be more compatible with the diagnosis of invasive malignancy. However, intracystic papillary carcinoma holds a favorable prognosis with local therapy alone. We report a case of intracystic papillary carcinoma in a male patient with long-standing gynecomastia diagnosed eight years prior by mammography. The patient presented with a breast lump on both occasions. Current work-up consisted of both mammography and ultrasound. Ultrasound provided key information revealing a complex mass requiring further evaluation. Ultrasound-guided core needle biopsy revealed intracystic papillary carcinoma with confirmation upon surgical excision.

Lesions of uncertain malignant potential in the breast (B3): what do we know?

Breast lesions classified as of uncertain malignant potential (B3) on biopsy form a diverse group of abnormalities, which pose a diagnostic and management challenge. In this paper, we discuss the imaging and pathology features as well as the management of the most controversial B3 lesions, consisting of papillary lesions, complex sclerosing lesions/radial scars, lobular intraepithelial neoplasia, and atypical epithelial proliferation of ductal type. As there is an association with malignancy at the time of diagnosis, as well as an increase in the risk of subsequent development of cancer, a multidisciplinary discussion is almost always required to tailor treatment.

Collagen Type XI Alpha 1 Expression in Intraductal Papillomas Predicts Malignant Recurrence

Despite the progress achieved in the treatment of breast cancer, there are still many unsolved clinical issues, being the diagnosis, prognosis, and treatment of papillary diseases, one of the highest challenges. Because of its unpredictable clinical behavior, treatment of intraductal papilloma has generated a great controversy. Even though considered as a benign lesion, it presents high rate of malignant recurrence. This is the reason why there are clinicians supporting a complete excision of the lesion, while others support an only expectant follow-up. Previous results of our group suggested that procollagen 11 alpha 1 (pro-COL11A1) expression correlates with infiltrating phenotype in breast lesions. We analyzed the correlation between expression of pro-COL11A1 in intraductal papilloma and their risk of malignant recurrence. Immunohistochemistry of pro-COL11A1 was performed in 62 samples of intraductal papilloma. Ten out 11 cases relapsed as carcinoma presents positive staining for COL11A1, while just 17 out of 51 cases with benign behaviour present immunostaining. There were significant differences (P < 0.0001) when comparing patients with malignant recurrence versus nonmalignant relapse patients. These data suggest that pro-COL11A1 expression is a highly sensitive biomarker to predict malignant relapse of intraductal papilloma and it can be used as indicative factor for prevention programs.

Challenges in the management of giant intraductal breast papilloma

The differential diagnosis of a large breast mass in a post-menopausal woman can include both benign and malignant etiologies. Although rare, diagnosis of giant intraductal papilloma must be considered in the differential. Furthermore, although benign, papillomas presenting as a large breast mass affecting the skin require extensive breast surgical treatment.

[Diagnostics of benign ductal epithelial cell proliferation of the breast in biopsy material]

The pathological evaluation of radiological or sonographical abnormalities by needle core biopsy of the breast frequently involves the differential diagnosis of benign epithelial cell proliferations. The lesions to be considered include usual type and atypical ductal epithelial cell hyperplasia, columnar cell changes including flat epithelial cell atypia, the spectrum of hyperplastic and atypical apocrine epithelial cell proliferations and papillary lesions. This review provides an overview of the diagnostic criteria, the current terminology and the differential diagnosis of these lesions. The clinical management and the prognosis of the lesions are discussed.

[Papillary lesions of the breast]

Papillary lesions of the breast encompass a spectrum of both benign and malignant lesions despite sharing a similar basic architecture. A reliable distinction between the different entities is possible even in biopsies with precise knowledge of the diagnostic criteria and using immunohistochemistry as a diagnostic adjunct. These include papilloma, papillary ductal carcinoma in situ, encapsulated papillary carcinoma and solid papillary carcinoma. Architectural features, cellular composition and distribution of myoepithelial cells as highlighted by immunohistochemistry are the major diagnostic criteria. In this review the most useful morphological and immunohistochemical criteria for routine diagnostic practice are presented.

Papillary Lesions on Core Breast Biopsy: Excisional Biopsy for All Patients?

Excisional biopsy has been recommended for papillary lesions diagnosed on core needle biopsy (CNB) because a significant proportion of cases are upstaged to in situ/invasive cancer after surgical excision. The study goals were to identify patients at lowest risk of upstaging in whom excisional biopsy may potentially be avoided. We retrospectively evaluated 46 patients with a papillary lesion on CNB. Six patients were upstaged overall (13%), to intraductal papillary carcinoma (7%), invasive papillary carcinoma (4%), and mixed invasive ductal/lobular carcinoma (2%). The upstaging rate for patients with atypia on CNB was higher than for patients without atypia (33 vs 3%, P = 0.011). No patient younger than 65 years was upstaged to in situ or invasive carcinoma, and the mean lesion size was also higher among patients who were upstaged ( P > 0.05). Patients younger than 65 years with small papillary lesions lacking atypia on CNB may therefore represent a low-risk group that may be offered close clinical and radiologic follow-up.

Benign papillomas without atypia diagnosed on core needle biopsy: experience from a single institution and proposed criteria for excision

BACKGROUND

The management of benign papilloma (BP) without atypia identified on breast core needle biopsy (CNB) is controversial. In this study, we determined the upgrade rate to malignancy for BPs without atypia diagnosed on CNB and whether there are factors associated with upgrade.

METHODS

Through our pathology database search, we studied 80 BPs without atypia identified on CNB from 80 patients from 1997 to 2010, including 30 lesions that had undergone excision and 50 lesions that had undergone ≥ 2 years of radiologic follow-up. Associations between surgery or upgrade to malignancy and clinical, radiologic, and pathologic features were analyzed.

RESULTS

Mass lesions, lesions sampled by ultrasound-guided CNB, and palpable lesions were associated with surgical excision. All 3 upgraded cases were mass lesions sampled by ultrasound-guided CNB. None of the lesions with radiologic follow-up only were upgraded to malignancy. The overall upgrade rate was 3.8%. None of the clinical, radiologic, or histologic features were predictive of upgrade.

CONCLUSION

Because the majority of patients can be safely managed with radiologic surveillance, a selective approach for surgical excision is recommended. Our proposed criteria for excision include pathologic/radiologic discordance or sampling by ultrasound-guided CNB without vacuum assistance when the patient is symptomatic or lesion size is ≥ 1.5 cm.

Uniqueness of ductal carcinoma in situ of the breast concurrent with papilloma: implications from a detailed topographical and histopathological study of 50 cases treated by mastectomy and wide local excision

AIMS

To clarify the diagnostic clues of ductal carcinomas in situ (DCIS) associated with papilloma and optimal clinical management of papilloma diagnosed on core needle biopsy (CNB).

METHODS AND RESULTS

A total of 50 surgically resected cases were examined histopathologically and topographically. Thirty-nine cases (78%) spread in segmental fashion. Papilloma and DCIS were intermingled closely in 44 cases (88%), occupying the same areas in varying proportions from DCIS-predominant to papilloma-predominant. The two components occupied discrete areas and collided focally in six cases (12%). Most were non-high-grade. Cribriform and solid architectures with fibrovascular stroma were frequent. The cribriform pattern was unique, consisting of fused tubules separated by fibrovascular stroma. Intraductal myoepithelial cells were present to varying degrees in 40 cases (80%). In 38 cases (76%), points were identified where papilloma and DCIS coexisted or collided within a single lumen (CC point). Forty-eight cases (96%) had either intraductal myoepithelial cells or CC points, implying that DCIS and papilloma existed in the same duct system. Radiology showed segmental abnormalities in 83% of the available cases.

CONCLUSIONS

Intraductal myoepithelial cells do not always guarantee benignity. Surgical resection is recommended for papilloma in CNB when radiology shows segmental abnormalities.

Radiologic-pathologic correlation at breast MR imaging: what is the appropriate management for high-risk lesions?

Breast magnetic resonance (MR) imaging is increasingly performed for a variety of indications, most commonly with the goal of detecting breast cancer. Percutaneous biopsy (usually under MR guidance or ultrasound if there is a correlating finding) is commonly used to evaluate suspicious imaging findings detected on MR imaging with the goal of identifying malignancy. It is important to be familiar with the characteristics and management of high-risk lesions detected or biopsied under MR guidance. This review focuses on the appearance of a variety of breast lesions detected on MR imaging that require excision with focus on pathologic correlation.

Comparison of sonographically guided core needle biopsy and excision in breast papillomas: clinical and sonographic features predictive of malignancy

OBJECTIVES

The aim of this study was to evaluate the clinical factors and sonographic features of benign papillomas of the breast proven by sonographically guided 14-gauge core needle biopsy and their upgrade or malignancy rate after sonographically guided vacuum-assisted excision or surgical excision.

METHODS

We reviewed the medical records of patients who underwent core needle biopsy from July 2005 to December 2011. We evaluated 39 benign papillomas without atypia in 34 patients. The papillomas were diagnosed by core needle biopsy and underwent surgical or vacuum-assisted excision. After core needle biopsy, imaging-histologic correlation was performed to determine concordance. The upgrade and malignancy rates were assessed after surgical or vacuum-assisted excision, and associated clinical and radiologic factors, including patient age, lesion size, distance from the nipple, sonographic features, and American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) category were evaluated.

RESULTS

Three lesions (7.7 %) among 39 papillomas were upgraded to papilloma with atypia after surgical excision. There was no malignancy after excision. The upgrade rates for BI-RADS categories 3, 4a, 4b, and 4c were 0%, 6.9%, 0%, and 20%, respectively. There were no significant differences in the upgrade to papilloma with atypia in terms of the presence of symptoms, lesion size, distance from the nipple, BI-RADS category, or imaging-histologic correlation.

CONCLUSIONS

Prediction of papilloma with atypia, not malignancy, was challenging because there were no associated clinical or radiologic factors to predict papilloma with atypia before excision. However, there was no malignancy after excision. Therefore, intensive surveillance is preferable to immediate surgical excision for benign papillomas diagnosed on core needle biopsy.

Benign papilloma diagnosed on image-guided 14 G core biopsy of the breast: effect of lesion type on likelihood of malignancy at excision

AIM

To ascertain the negative predictive value (NPV) for atypia and malignancy of 14 G core biopsy of papillomas and to determine whether lesion type influences the likelihood of malignancy at lesion excision.

MATERIALS AND METHODS

Ninety-six lesions with a 14 G core biopsy diagnosis of benign papilloma without atypia in 95 women were included. The imaging features (mass or microcalcification), biopsy mode, and number of core samples taken were documented. All patients subsequently underwent lesion excision with either extensive vacuum-assisted biopsy (VAB; 72 lesions) or surgery (24 lesions). Mammographic follow-up of at least 2 years was available for 32 lesions that were benign at VAB.

RESULTS

Atypia or malignancy was found more commonly in association with microcalcification (six of 29 lesions: 21%; median number of nine 14 G cores) than a mass (five of 67 lesions: 7%; median number of three 14 G cores), although the difference does not reach statistical significance (p = 0.088). The NPV of a 14 G core biopsy diagnosis of papilloma for atypia or malignancy is 89% (85/96). Disease underestimation may be more common in microcalcification lesions despite the greater number of cores obtained.

CONCLUSION

Excision (using VAB or surgically) of all papillomas diagnosed as benign on 14 G needle core biopsy is recommended. Surgery may be more appropriate than VAB for some microcalcification lesions unless they are small and can be confidently removed in their entirety using VAB.

Pathologic outcomes of nonmalignant papillary breast lesions diagnosed at imaging-guided core needle biopsy

PURPOSE

To determine the upstage rate from nonmalignant papillary breast lesions obtained at imaging-guided core needle biopsy (CNB) and if there are any clinical, imaging, or pathologic features that can be used to predict eventual upstaging to malignancy.

MATERIALS AND METHODS

This retrospective case review was institutional review board approved and HIPAA compliant, with a waiver of informed consent. A database search (from January 2001 to March 2010) was performed to find patients with a nonmalignant papillary breast lesion diagnosed at CNB. Of the resulting 128 patients, 86 (67%) underwent surgical excision; 42 (33%) patients were observed with imaging, for a median observation time of 4.1 years (range, 1.0-8.6 years). Chart review was performed to determine pertinent features of each case.

RESULTS

Fourteen of 128 patients were subsequently found to have malignancy at excision, for an upstage rate of 11%. Nine (7%) of the 128 patients were subsequently found to have atypia at excision. Comparisons between patients with upstaged lesions and patients whose lesions were not upstaged demonstrated patients with upstaged lesions to be slightly older (65 vs 56 years, P=.01), more likely to have a mass than calcifications at imaging (P=.03), and to have had less tissue obtained at biopsy (three vs five cores obtained, P=.02; 14- vs 9-gauge needle used, P<.01; no vacuum assistance used, P<.01). Most strongly predictive of eventual malignancy, however, was whether the interpreting pathologist qualified the benign diagnosis at CNB with additional commentary (P<.01).

CONCLUSION

Given the substantial upstage rate (11%) of papillary lesions diagnosed at imaging-guided CNB, surgical excision is an appropriate management decision; however, careful evaluation in concert with an expert breast pathologist may allow for observation in appropriately selected patients.