Histological features useful in the distinction of phyllodes tumour and fibroadenoma on needle core biopsy of the breast

Borderline Phyllodes Tumor in a Child

Phyllodes tumor (PT) is considered a rare fibroepithelial tumor. Very few series have been reported in children and adolescents. Based on histopathological features, it can be classified as benign, borderline, or malignant, with the latter having a more aggressive clinical behavior. We report the case of a 10-year-old female who began with an asymptomatic mobile right breast mass. An initial fine needle biopsy (FNB) concluded fibroadenoma (FA). Months later, the mass kept growing, with the appearance of pain and nipple discharge. Benign PT was demonstrated in a new biopsy. A total mastectomy was performed. The post-surgical histopathological examination was compatible with a borderline PT. The patient is now symptom-free and with no signs of relapse. Not all breast masses in the pediatric or adolescent age bracket are FA. Attention is warranted when the clinical behavior does not follow the usual outline. PT has to be considered as a possible diagnosis and treated accordingly.

"Growing fibroadenoma": Are there clinical and pathological features predicting a phyllodes tumor on surgical excision?

In cases of growth of FA on imaging, core needle biopsies (CNB) are often performed to rule out phyllodes tumor (PT). We aim to focus on "growing FAs" and to identify clinical and histopathologic features that are likely to predict a PT on excision. Thirty-four FAs with radiologic documentation of growth were included. Various clinical and pathological features such as age, body mass index (BMI), lesion size, and growth rate were recorded. On excision, 17 cases (50 %) were FAs, whereas 16 (47 %) were re-classified as benign PT despite only 19 % being suspicious for PT on CNB. PT patients were older (mean age 42.6) than those with FAs (mean age 28.2), p = 0.0002. All false negative cases demonstrated intracanalicular growth. Mitotic rate was the most significant histologic feature in PT on excision compared to others, such as lesion circumscription and stromal cellularity. Recognition and careful counting of mitotic rate, especially with intracanalicular patterns in growing FAs, can potentially prevent missing a PT on CNB. In patients with "growing FAs" who are ≥40 years of age, excision may be recommended due to the high likelihood of PT diagnosis on excision and high false negative rate on CNB.

Combined use of shear-wave elastography and Doppler ultrasonography in equivocal fibroepithelial lesions of the breast diagnosed by core needle biopsy

PURPOSE

The aim of this study was to evaluate the diagnostic value of shear-wave elastography (SWE) combined with Doppler ultrasonography (US) in selecting equivocal breast fibroepithelial lesions (FELs) for follow-up without further excision.

METHODS

A retrospective analysis was conducted of 88 patients with equivocal breast FELs (FELs with the possibility of both fibroadenoma [FA] and phyllodes tumor [PT]) diagnosed by core needle biopsy (CNB). For post-CNB treatment, surgical or vacuum-assisted excision was performed on 88 equivocal FELs, of which 56 were diagnosed as FAs and 32 as PTs on histopathology. Mean elasticity (Emean) and vascularity were determined using SWE and Doppler US. The diagnostic performances of B-mode US, SWE, and Doppler US were calculated to differentiate FAs and PTs in the excised equivocal FELs.

RESULTS

In the excised equivocal FELs diagnosed by CNB, FAs showed significantly lower median Emean values (36.4 vs. 66.7 kPa, P=0.005) and more frequent low vascularity (0-1 vessel flow signal) (P<0.001) than PTs. For the differentiation of FAs and PTs, the combination of Emean of >60.9 kPa and high vascularity (≥2 vessel flows) showed a sensitivity and negative predictive value of 100%, as well as better performance in other diagnostic values than B-mode US alone (Breast Imaging Reporting and Data System ≥4A) (all P<0.05).

CONCLUSION

Equivocal breast FELs showing both low elasticity and low vascularity were not upgraded to PTs upon further excision. Therefore, the combination of SWE and color Doppler US mode might help select patients with equivocal FELs for whom further excision is unnecessary.

Survey of recurrent diagnostic challenges in breast phyllodes tumours

BACKGROUND

Breast phyllodes tumours (PTs) are graded as benign, borderline, or malignant by analysis of multiple histological features. PT grading is often inconsistent, likely due to variation in the weighting of grading criteria by pathologists.

DESIGN

The hierarchy of use of diagnostic criteria was identified using a 20-question survey.

RESULTS

In all, 213 pathologists from 29 countries responded. 54% reported 10-50 PT cases per year. Criteria considered key to PT diagnosis were: increased stromal cellularity (84.3%), stromal overgrowth (76.6%), increased stromal mitoses (67.8%), stromal atypia (61.5%), stromal fronding (59.0%), periductal stromal condensation (58.0%), irregular tumour borders (46.3%), and/or lesional heterogeneity (33.7%). The importance of grading parameters were: mitotic activity (55.5%), stromal overgrowth (54.0%), stromal atypia (51.9%), increased stromal cellularity (41.7%), and nature of the tumour border (38.9%). 49% would diagnose malignant PT without a full array of adverse features. 89% used the term "cellular fibroepithelial lesion (FEL)" for difficult cases; 45% would diagnose an FEL with stromal fronding (but lacking other PT features) as fibroadenoma (FA), 35% FEL, and 17% PT. 59% deemed clinico-radiological findings diagnostically significant; 68% considered age (≥40 years) important in determining if an FEL was a FA or PT. In FELs from young patients, increased stromal cellularity (83%), fronding (52%), and mitoses (41%) were more common. 34% regarded differentiating cellular FA from PT as a specific challenge; 54% had issues assigning a borderline PT grade.

CONCLUSION

Criteria for grading PT lie on a spectrum, leading to interpretive variability. The survey highlights the criteria most used by pathologists, which do not completely align with WHO recommendations.

Contrast-enhanced spectral mammographic findings of phyllodes tumor of the breast

Background

Phyllodes tumors of breast are rare fibroepithelial neoplasms. They have similar radiological findings with fibroadenomas. While fibroadenomas are benign lesions, phyllodes tumors may have malignant potential. Therefore, any imaging findings to differentiate fibroadenoma from phyllodes tumor are valuable.

Case presentation

A 51-year-old female patient was admitted to our clinic with the complaint of a palpable mass. Tru-Cut biopsy resulted as phyllodes tumor, and excision was recommended. However, the patient neglected herself during the COVID-19 pandemic, and 20 months later, she presented with a huge and complex mass. On CESM imaging, cystic areas and clefts were identified. The case was diagnosed as borderline phyllodes tumor.

Conclusions

Although MRI findings of phyllodes tumor are well known and reported many times, there is no information about CESM findings of this tumor in literature. Bubbly appearance on CESM is useful finding in the diagnosis of phyllodes tumor of breast.

Logistic regression analysis of ultrasound findings in predicting the malignant and benign phyllodes tumor of breast

OBJECTIVE

To evaluate ultrasound characteristics in the prediction of malignant and benign phyllodes tumor of the breast (PTB) by using Logistic regression analysis.

METHODS

79 lesions diagnosed as PTB by pathology were analyzed retrospectively. The ultrasound features of PTB were recorded and compared between benign and malignant tumors by using single factor and multiple stepwise Logistic regression analysis. Moreover, the Logistic regression model for malignancy prediction was also established.

RESULTS

There were 79 patients with PTB, including 39 benign PTBs and 40 malignant PTBs (33 borderline PTBs and 7 malignant PTBs by pathologic classification). The area under the ROC curve (AUC) of lesion size and age were 0.737 and 0.850 respectively. There were significant differences in age, lesion size, shape, internal echo, liquefaction, and blood flow between malignant and benign PTBs by using single-factor analysis (P<0.05). Age, internal echo, and liquefaction were significant features by using Logistic regression analysis. The corresponding regression equation In (p/(1 - p) = -3.676+2.919 internal echo +3.029 liquefaction +4.346 age).

CONCLUSION

Internal echo, age, and liquefaction are independent ultrasound characteristics in predicting the malignancy of PTBs.

Artificial intelligence modelling in differentiating core biopsies of fibroadenoma from phyllodes tumor

Breast fibroepithelial lesions (FEL) are biphasic tumors which consist of benign fibroadenomas (FAs) and the rarer phyllodes tumors (PTs). FAs and PTs have overlapping features, but have different clinical management, which makes correct core biopsy diagnosis important. This study used whole-slide images (WSIs) of 187 FA and 100 PT core biopsies, to investigate the potential role of artificial intelligence (AI) in FEL diagnosis. A total of 9228 FA patches and 6443 PT patches was generated from WSIs of the training subset, with each patch being 224 × 224 pixel in size. Our model employed a two-stage architecture comprising a convolutional neural network (CNN) component for feature extraction from the patches, and a recurrent neural network (RNN) component for whole-slide classification using activation values from the global average pooling layer in the CNN model. It achieved an overall slide-level accuracy of 87.5%, with accuracies of 80% and 95% for FA and PT slides respectively. This affirms the potential role of AI in diagnostic discrimination between FA and PT on core biopsies which may be further refined for use in routine practice.

Which lesions with a radiological or core biopsy diagnosis of fibroadenoma should be excised?

INTRODUCTION

A recent Association of Breast Surgery summary statement on fibroadenoma management recommends excision only for cellular fibroepithelial lesions and rapidly growing lesions with a core biopsy diagnosis of fibroadenoma; persistent pain is a relative indication for excision.

METHODS

This retrospective study looked at the impact this approach would have on the diagnosis of phyllodes tumours.

RESULTS

From 2014 to 2018, there were 1,058 core biopsy diagnoses of fibroadenoma; 112 lesions were excised, of which 98 were fibroadenomas, 4 were hamartomas and 10 were phyllodes tumours. In this group, an excision diagnosis of phyllodes tumour was associated with size more than 40 mm, age more than 40 years and radiological suspicion of phyllodes tumour or carcinoma. One hundred and sixty-six excised fibroepithelial lesions with no previous core biopsy included eight phyllodes tumours; in this group, rapid growth was associated with phyllodes tumour diagnosis. Twelve of the 26 fibroepithelial lesions classified as B3 (cellular fibroepithelial lesion or phyllodes tumour) were diagnosed as phyllodes tumours on excision. Using a combination of radiological, clinical and pathological features it was possible to create an excision policy that would recommend excision of 22 of the 31 phyllodes tumours in this period. Eight of the nine 'missed' phyllodes tumours were benign.

CONCLUSION

The Association of Breast Surgery summary statement will reduce the number of fibroadenomas excised, but may also result in delayed diagnosis of some phyllodes tumours. Appropriate safety netting advice should be provided to identify rapidly growing lesions.

Fibroepithelial tumours of the breast-a review

Fibroepithelial tumours of the breast are biphasic neoplasms composed of both epithelial and stromal elements, including the common fibroadenoma and the infrequent phyllodes tumour. The admixture of epithelium and stroma in the fibroadenoma shows intra- and pericanalicular patterns, and may display a variety of histological changes. Fibroadenoma variants include the cellular, juvenile, myxoid and complex forms. The cellular fibroadenoma may be difficult to distinguish from the benign phyllodes tumour. Stromal mitotic activity can be increased in fibroadenomas in the young and pregnant patients. Phyllodes tumours, neoplasms with the potential for recurrence, show an exaggerated intracanalicular growth pattern with broad stromal fronded architecture and stromal hypercellularity. They are graded into benign, borderline and malignant forms based on histological assessment of stromal features of hypercellularity, atypia, mitotic activity, overgrowth and the nature of the tumour borders. Classification of phyllodes tumours is imperfect, compounded by tumour heterogeneity with overlapping microscopic features among the different grades, especially in the borderline category. Malignant phyllodes tumours can metastasise and cause death. Determining which phyllodes tumours may behave aggressively has been difficult. The discovery of MED12 mutations in the pathogenesis of fibroepithelial tumours, together with other gene abnormalities in the progression pathway, has allowed refinements in diagnosis and prognosis.

Genetic differences between benign phyllodes tumors and fibroadenomas revealed through targeted next generation sequencing

Breast fibroepithelial lesions are biphasic tumors which comprise the common benign fibroadenomas (FAs) and the rarer phyllodes tumors (PTs). This study analyzed 262 (42%) conventional FAs, 45 (7%) cellular FAs, and 321 (51%) benign PTs contributed by the International Fibroepithelial Consortium, using a previously curated 16 gene panel. Benign PTs were found to possess a higher number of mutations, and higher rates of cancer driver gene alterations than both groups of FAs, in particular MED12, TERT promoter, RARA, FLNA, SETD2, RB1, and EGFR. Cases with MED12 mutations were also more likely to have TERT promoter, RARA, SETD2, and EGFR. There were no significant differences detected between conventional FAs and cellular FAs, except for PIK3CA and MAP3K1. TERT promoter alterations were most optimal in discriminating between FAs and benign PTs. Our study affirms the role of sequencing and key mutations that may assist in refining diagnoses of these lesions.

Use of Lateral Oncoplasty for Multiquadrant Giant Fibroadenoma: A Novel Approach

Giant fibroadenomas are uncommon benign lesions, defined as fibroadenomas of >5 cm in size and/or weighing more than 500 g. They can distort the shape of the breast and cause asymmetry, so they should be excised. Here, we report two cases of giant fibroadenoma, where wide local excision and reconstruction with lateral oncoplasty were done. Compared to all previous reports of patients with giant fibroadenoma, where the lump was excised either through a submammary incision or by round block technique depending on the location of the tumour, we used the lateral oncoplasty technique in both patients. Lateral oncoplasty is a new reconstructive option to maintain cosmesis and symmetry after the excision of giant fibroadenomas in the outer and central quadrants of the breast. It is a good option for reconstruction in cases where the defect is very large and facilities for conventional flap surgeries are not available.

Use of breast imaging-reporting and data system (BI-RADS) ultrasound classification in pediatric and adolescent patients overestimates likelihood of malignancy

BACKGROUND/PURPOSE

Breast masses in the pediatric population cause patient and family concern, partially driven by public awareness of adult breast cancer. However, the spectrum of breast masses in children differs greatly from that in adults, and malignancy is exceedingly rare. The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) ultrasound-based classification system is the diagnostic standard, yet no study has validated BI-RADS in pediatric patients. This study compares BI-RADS classification with histologic diagnoses to evaluate BI-RADS validity in pediatric patients.

METHODS

Multicenter retrospective evaluation of breast masses in patients under 21 years. Ultrasound reports were compared with histologic diagnoses.

RESULTS

There were 283 patients with breast pathology results after excluding clinical diagnoses of gynecomastia. Mean age was 16.9 (SD 2.3), ranging 10-20 years. 227 had pre-operative ultrasounds, and 84% (191/227) were assigned a BI-RADS category. BI-RADS 4 was the most frequent category (55%, n = 124), by definition predicting 2 - 95% likelihood of malignancy. However, pathology was benign in all patients.

CONCLUSIONS

The current BI-RADS categorization system overestimates cancer risk when applied to pediatric patients. BI-RADS scores should not be assigned to pediatric patients, and BIRADS-defined recommendations for biopsy should be disregarded. A pediatric-specific classification system could be useful.

Correlations of morphological features and surgical management with clinical outcome in a multicentre study of 241 phyllodes tumours of the breast

AIMS

Phyllodes tumours (PTs) represent an unusual but complex group of breast lesions with a tendency to recur locally and, less commonly, metastasise. On core biopsies, their appearances can be difficult to discriminate from those of other fibroepithelial lesions, which may compromise their surgical management. The aims of this study were to assess the preoperative diagnosis of PTs and to evaluate the impacts of surgical management and morphological features on their behaviour.

METHODS AND RESULTS

We combined datasets from three centres over two decades, including core biopsies, excision specimens, and follow-up. Core biopsy results were compared with final excision specimens. The relationships of surgical procedure and morphological features with local recurrence (LR) and metastasis were assessed. Two hundred and forty-one PTs were studied. Core biopsy resulted in a diagnosis of possible or definite PT in 76% of cases. Malignant tumours were more likely to be larger, occurred at an older age, and were surgically more challenging, with difficulties being encountered in achieving negative margins. There were 12 cases (5%) that showed LR alone, and another six cases (2.5%) that had distant metastases. Morphological features associated with adverse outcome were grade of PT, increased mitotic counts, necrosis, infiltrative margins, stromal atypia, and heterologous components. Both LR and metastatic behaviour correlated with larger size and distance to margins.

CONCLUSIONS

Our results suggest that excision margins have a significant impact on LR of PT, whereas metastatic behaviour is influenced by tumour biology. We add to the evidence base on histological features of tumours that contribute to long-term outcomes of PT patients.

Phyllodes tumor of the breast clinical experience and outcomes: A retrospective cohort tertiary hospital experience

BACKGROUND

Phyllodes tumor (PT) accounts for <1% of all breast tumors worldwide. Based on their microscopic features, these tumors are classified into benign, borderline, and malignant. This study aimed at evaluating the clinical experience and the clinicopathologic features of PT.

METHODS

A retrospective cohort study of 46 female patients with histologically diagnosed PT. Data collection and evaluation was done on patient demographics, preoperative radiological assessment and pathology, surgical procedure, post-surgery pathological evaluation, radiation therapy (RT), and follow-up.

RESULTS

The median age at diagnosis was 42 years and young premenopausal patients (median age 35 years) had malignant PT. Forty-five patients underwent core needle biopsy (CNB) with high sensitivity and the positive predictive value (82.2% and 97.4% respectively). Thirty-nine patients (86.7%) underwent conservative surgery and 6 (13.3%) had a mastectomy. Twenty-seven (58.6%) were classified as benign, 11 (23.9%) as borderline and only 8 (17.4%) as malignant PT. Malignant PT had the greatest median tumor size (13 cm). Mortality and recurrence rates were 4.3% and 2.2% respectively. RT was administered in 6 patients (13.0%), 5 having malignant and 1 borderline PT. The metastatic rate was found to be 6.5%.

CONCLUSION

PT are rare breast tumors with variable biologic behavior and heterogenous clinicopathological findings. Young, premenopausal women with large tumors may have malignant PT with a risk of recurrence and metastasis. Core needle biopsy is a reliable tool for diagnosis of PT with strict follow-up recommended for large tumors diagnosed as fibroadenoma on CNB. Surgical management must ensure a tumor-free margin on excision to reduce recurrence.

Fibroepithelial lesions revisited: implications for diagnosis and management

Fibroepithelial lesions of the breast, comprising the fibroadenoma and phyllodes tumour, are a unique group of neoplasms that share histological characteristics but possess different clinical behaviour. The fibroadenoma is the commonest benign breast tumour in women, while the phyllodes tumour is rare and may be associated with recurrences, grade progression and even metastasis. The diagnosis of fibroadenoma is usually straightforward, with recognised histological variants such as the cellular, complex, juvenile and myxoid forms. The phyllodes tumour comprises benign, borderline and malignant varieties, graded using a constellation of histological parameters based on stromal characteristics of hypercellularity, atypia, mitoses, overgrowth and the nature of tumour borders. While phyllodes tumour grade correlates with clinical behaviour, interobserver variability in assessing multiple parameters that are potentially of different biological weightage leads to significant challenges in accurate grade determination and consequently therapy. Differential diagnostic considerations along the spectrum of fibroepithelial tumours can be problematic in routine practice. Recent discoveries of the molecular underpinnings of these tumours may have diagnostic, prognostic and therapeutic implications.

World's Oldest Case of Synchronous Bilateral Benign Phyllodes Tumors of the Breast: A Rare Occurrence

Phyllodes tumors are rare fibroepithelial tumors of the breast. They account for less than 0.5% of breast cancers. Bilateral presentation is a rare event, and seems to be associated with the more benign subtype but, reports are scarce. It is more common to have multiple ipsilateral tumors or bilateral asynchronous presentations. However, bilateral synchronous phyllodes are seldom reported. A literature search has revealed only five cases of synchronous and one case of metachronous bilateral phyllodes tumor of the breast. The age ranges of these patients are between 16-42 years. We are reporting the world's first case of bilateral synchronous phyllodes tumor of the breast in a patient over the age of 50 years.

Ki67 and P53 Expression in Relation to Clinicopathological Features in Phyllodes Tumour of the Breast

OBJECTIVE

Phyllodes tumour (PT) is a rare fibroepithelial neoplasm of the breast that carries a risk of malignancy. Histopathological examination remains a gold standard for diagnosis. The usage of the immunohistochemical markers of Ki67 and p53 acts as a supplement method, particularly for the malignant PT. We aim here to study the expression of these markers in PT and to see their relation to the tumour grading.

METHODOLOGY

We conducted a retrospective cross-sectional study on 57 archived formalin-fixed paraffin-embedded tissue blocks of PT from the years 2015 to 2018 from two hospitals in East Coast Malaysia. The histopathological examination and immunohistochemical stain for Ki67 and p53 were analysed.

RESULTS

There was an association between clinical descriptive data of skin changes, lump size of more than 3 cm, cytological atypia, stromal hypercellularity, mitosis and immunohistochemistry with the clinical diagnosis of PT. Both marked expression of Ki67 and p53 were seen in borderline and malignant PT. Our study showed that in the presence of high mitotic figures, marked expression of Ki67 was only seen in cases of malignant PT.

CONCLUSION

We found a significant association of Ki67 and p53 expressions, high mitosis and other descriptive histopathological features in malignant PT. Further study with larger sample size is recommended to predict tumour grade and prognosis as well as the disease-free survival of the tumour. 
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Core needle biopsy diagnosis of fibroepithelial lesions of the breast: a diagnostic challenge

Fibroepithelial lesions (FEL) of the breast are biphasic neoplasms consisting of proliferative epithelial and stromal components and include fibroadenoma, phyllodes tumour and periductal stromal tumour. Core needle biopsy (CNB) is a commonly used diagnostic modality for investigation of breast lesions. As the accurate diagnosis of FEL requires integrated assessment of both epithelial and stromal components, this may create problems in small biopsies with limited sampling. In this review, common problems encountered in CNB of FEL are discussed, including establishing a diagnosis of borderline/malignant phyllodes tumour in a biopsy consisting of malignant spindle cells, differentiating phyllodes tumour from fibroadenoma on CNB, grading of phyllodes tumour of intermediate histological grade and assessment of periductal stromal tumours. The approaches are detailed systematically based on histology, immunohistochemistry and molecular characterisation. This comprehensive approach may aid in dealing with the overlapping histological appearance of FEL and sampling limitations of CNB.

A Giant Exulcerated Phyllodes Breast Tumor - A Case Report

Phyllodes tumors of the breast can be benign, malignant, or borderline. Benign and borderline tumors are rare tumor types that have a positive outlook and high survival rate, while the risk of recurrence is typical for malignant breast tumors. Giant phyllodes tumors are larger than 10 cm in diameter and demand a serious diagnostic and treatment approach.

In this study we present a case of a female patient treated for an exulcerated breast carcinoma- a giant borderline phyllodes tumor of the breast. The patient presented to the department for the right breast lump with ulcerated skin and nipple abnormalities. The core biopsy was performed and the patient was diagnosed with a benign tumor. Simple mastectomy was performed and final histopathological report revealed a borderline phyllodes tumor. Diagnosis and treatment of a giant phyllodes tumor remain a great challenge for the surgeons. Establishing the preoperative diagnosis based on histopathological findings is imperative to disease management. Surgery is the mainstay of treatment and mastectomy has been the traditional procedure; in cases where suspicious findings in the axilla are revealed, radical mastectomy is performed and the axilla is to be dissected.

Giant fibroadenoma of the breast: A rare case in a mature woman

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We experienced giant fibroadenoma of breast, a rare case in a mature woman.

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We suspected a malignant tumor, due to the size and ulceration and bleeding.

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Total mastectomy and skin grafting were needed for complete resection.

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An early diagnosis and treatment could prevent total mastectomy.

Introduction

Fibroadenomas are common benign lesions of the breast that are usually found young patients. Giant fibroadenomas are uncommon benign lesions, defined as fibroadenomas of >5 cm in size, which are usually found in patients of less than 20 years of age.

Presentation of case

A 39-year-old premenopausal woman presented with a right breast tumor that had rapidly increased in size and which showed ulceration and bleeding. Needle biopsy showed mixed connective tissue and an epithelial tumor without a leaf-like pattern, but indeterminate. Total mastectomy and skin grafting were performed. Histopathology confirmed the diagnosis of giant fibroadenoma.

Discussion

In comparison to all previous reports on patients with giant fibroadenoma, this patient was relatively old and the etiology was unknown. Although rare, an appropriate therapeutic strategy should be decided according to the results of a histopathological examination.

Conclusion

Early treatment could allow breast preserving surgery and patients should be recommended to undergo reexamination with awareness of progression.

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.

Accuracy and clinical implications of pre-operative breast core needle biopsy diagnoses of fibroepithelial neoplasms and sarcomatoid carcinomas

PURPOSE

Accurate classification of breast phyllodes tumors (PTs) on core biopsy can be challenging. The differential diagnosis of benign PT (BP) is fibroadenoma (FA), whereas the differential diagnosis of malignant PT (MP) is sarcomatoid (metaplastic) carcinoma (SC).

METHODS

Here, we compare the pre-excision core biopsy diagnosis and clinicopathologic features of histologically confirmed MP, borderline PT (BLP), BP, FA, and SC. Consecutive cases of 34 histologically confirmed PT (14 MP, 10 BLP, 10 BP), 13 SC, and 10 FA were identified.

RESULTS

A core biopsy diagnosis of SC was made only in SC (77%, p = 0.003). The diagnosis "malignant neoplasm" or "atypical spindle cell neoplasm" was made in 100% MP and 23% SC, but no other tumor (p = 0.0001). The diagnosis "phyllodes tumor" was made only in PT (44% BLP, 11% BP, p = 0.06). The diagnosis "fibroepithelial lesion" was made in 44% BLP, 67% BP, and 29% FA. The diagnosis "FA" was made most commonly in FA (57%) (versus 22% BP and no other tumor; p = 0.002). Neoadjuvant therapy was given only in SC (23%, p = 0.03); adjuvant therapy was given in 46% SC and 13% MP (p = 0.04).

CONCLUSIONS

A pre-operative core biopsy diagnosis of "malignant spindle cell neoplasm" separates MP and SC from BLP, BP, and FA. However, MP and SC can have overlapping features on core biopsy. Thus, one must be careful not to overcall SC on core biopsy, as patients diagnosed with SC may receive neoadjuvant therapy. A core biopsy diagnosis of "phyllodes tumor" is specific for PT and can guide treatment planning of a wide local excision.

Development of a Management Algorithm for the Diagnosis of Cellular Fibroepithelial Lesions From Core Needle Biopsies

Purpose. Surgical excision is recommended for complete evaluation of cellular fibroepithelial lesions identified from core needle biopsy. The purpose of this study was to determine factors associated with phyllodes tumor among cellular fibroepithelial lesions from core biopsies and develop a scoring system to predict the risk of phyllodes tumor. Methods. We retrospectively reviewed clinical data of 169 breast lesions that were diagnosed as cellular fibroepithelial lesions from core needle biopsy at the Seoul National University Bundang Hospital between March 2005 and January 2013. The clinical, histopathologic, and radiologic characteristics were compared between phyllodes tumors and fibroadenomas during the final diagnosis after surgical excision. Results. Of the 169 lesions, 17 were observed and 152 were surgically removed. After excision, final pathology revealed 60 (39.5%) fibroadenomas and 92 (60.5%) phyllodes tumors. Multivariate analysis demonstrated that age (≥40 years), stromal overgrowth, and stromal cellularity were independent factors associated with phyllodes tumors. A scoring system was developed based on a multivariate logistic regression model, and the area under the receiver operating characteristic curve was 0.828 (95% confidence interval = 0.763-0.893). Conclusion. The scoring system will help clinicians make appropriate treatment for patients with cellular fibroepithelial lesions on core needle biopsy.

Interobserver variation in the diagnosis of fibroepithelial lesions of the breast: a multicentre audit by digital pathology

Aim

Fibroepithelial lesions (FELs) of the breast span a morphological continuum including lesions where distinction between cellular fibroadenoma (FA) and benign phyllodes tumour (PT) is difficult. The distinction is clinically important with FAs managed conservatively while equivocal lesions and PTs are managed with surgery. We sought to audit core biopsy diagnoses of equivocal FELs by digital pathology and to investigate whether digital point counting is useful in clarifying FEL diagnoses.

Method

Scanned slide images from cores and subsequent excisions of 69 equivocal FELs were examined in a multicentre audit by eight pathologists to determine the agreement and accuracy of core needle biopsy (CNB) diagnoses and by digital point counting of stromal cellularity and expansion to determine if classification could be improved.

Results

Interobserver variation was high on CNB with a unanimous diagnosis from all pathologists in only eight cases of FA, diagnoses of both FA and PT on the same CNB in 15 and a ‘weak’ mean kappa agreement between pathologists (k=0.36). ‘Moderate’ agreement was observed on CNBs among breast specialists (k=0.44) and on excision samples (k=0.49). Up to 23% of lesions confidently diagnosed as FA on CNB were PT on excision and up to 30% of lesions confidently diagnosed as PT on CNB were FA on excision. Digital point counting did not aid in the classification of FELs.

Conclusion

Accurate and reproducible diagnosis of equivocal FELs is difficult, particularly on CNB, resulting in poor interobserver agreement and suboptimal accuracy. Given the diagnostic difficulty, and surgical implications, equivocal FELs should be reported in consultation with experienced breast pathologists as a small number of benign FAs can be selected out from equivocal lesions.

Phyllodes Tumor of the Breast: Ultrasound-Pathology Correlation

OBJECTIVE

The purpose of this study is to evaluate the sonographic and histopathologic features distinguishing benign from borderline and malignant phyllodes tumors.

MATERIALS AND METHODS

The ultrasound examinations of women with pathologically proven phyllodes tumors from 2004 to 2011 were retrospectively reviewed. The sonographic features of benign, borderline, and malignant phyllodes tumors were compared and analyzed using the American College of Radiology's BI-RADS ultrasound lexicon. Fisher exact test and Wilcoxon rank sum test were used for statistical analysis.

RESULTS

Fifty-nine women were included in the study; 28 benign (47%), 19 malignant (32%), and 12 borderline (20%) phyllodes tumors were identified. Significant univariate predictors of increased risk of borderline or malignant phyllodes tumors were patient age greater than 55 years (p = 0.014), irregular lesion shape (p = 0.011), and longest lesion dimension greater than 7 cm (p = 0.0022) at sonography. No significant differences were observed in lesion margins, boundaries, echo patterns, or posterior acoustic features.

CONCLUSION

There is substantial overlap in the sonographic features of benign and borderline or malignant phyllodes tumors. Understanding the clinical and sonographic features of phyllodes tumors may aid the radiologist in predicting biological behavior, including the likelihood of benign versus borderline or malignant phyllodes tumors at pathologic analysis.

A Diagnostic Approach to Fibroepithelial Breast Lesions

Fibroepithelial breast lesions encompass a heterogeneous group of neoplasms that range from benign to malignant, each exhibiting differing degrees of stromal proliferation in relation to the epithelial compartment. Fibroadenomas are common benign neoplasms that may be treated conservatively. Phyllodes tumors are relatively rare lesions, and classified as benign, borderline, or malignant based on histologic evaluation of various parameters. The diagnostic interpretation of "gray-zone" fibroepithelial lesions often imposes formidable demands on a pathologist's skills. This article offers practical recommendations for the diagnostic workup of these lesions, including the appropriate utilization of ancillary investigations and the approach to core needle biopsies.

Benign Breast Diseases: Evaluation and Management

Benign breast disease is a spectrum of common disorders. The majority of patients with a clinical breast lesion will have benign process. Management involves symptom control when present, pathologic-based and imaging-based evaluation to distinguish from a malignant process, and counseling for patients that have an increased breast cancer risk due to the benign disorder.

Validation of the Singapore nomogram for outcome prediction in breast phyllodes tumours in a large patient cohort

Aims

To validate the Singapore nomogram for outcome prediction in breast phyllodes tumours in a large cohort of Singaporean patients, as previous validation studies were conducted on small numbers of patients. We also investigate the association of fibroadenomas and phyllodes tumours within a subset of our cohort.

Methods

Histological parameters, surgical margin status and clinical follow-up data of 259 women diagnosed with phyllodes tumours were analysed. Patients with concurrent malignant or premalignant disease were excluded from the validation to minimise confounding influences. Biostatistics modelling was performed, and the concordance between predicted and observed survivals was calculated. The association between fibroadenomas and phyllodes tumours was quantified in a subset of the women.

Results

Phyllodes tumours with higher number of mitoses, stromal overgrowth and positive surgical margins were found to be associated with greater risk of clinical recurrence. Patients with a higher nomogram score had a significantly higher risk of developing relapse. Forty out of 78 (51.3%) of the subset of phyllodes cases reviewed showed either fibroadenoma-like areas within the phyllodes tumours or concurrent fibroadenomas in the ipsilateral or contralateral breast.

Conclusions

The Singapore nomogram is useful in predicting outcome in breast phyllodes tumours when applied to a large cohort of Singaporean women.

Fibroepithelial lesions; The WHO spectrum

Fibroepithelial lesions of the breast comprise a morphologically and biologically heterogeneous group of biphasic tumors with epithelial and stromal components that demonstrate widely variable clinical behavior. Fibroadenomas are common benign tumors with a number of histologic variants, most of which pose no diagnostic challenge. Cellular and juvenile fibroadenomas can have overlapping features with phyllodes tumors and should be recognized. Phyllodes tumors constitute a spectrum of lesions with varying clinical behavior and are graded as benign, borderline or malignant based on a set of histologic features according to recommendations by the World Health Organization (WHO). Recent developments have significantly expanded our understanding of the pathogenesis of fibroepithelial lesions, highlighting fibroadenomas as true neoplasms and underscoring a commonality with phyllodes tumors in the form of recurrent MED12 exon 2 mutations. In addition, sequencing studies have elucidated pathways associated with phyllodes tumor progression. Accurate diagnosis and grading of phyllodes tumors are important for patient management and prognosis, as grade broadly correlates with increasing local recurrence risk, and essentially only malignant tumors metastasize. However, classification of fibroepithelial lesions in many cases remains challenging on both core biopsy and excision specimens. A commonly encountered problem at the benign end of the spectrum is the distinction of benign phyllodes tumor from cellular fibroadenoma, which is largely due to the subjective nature of histologic features used in diagnosis and histologic overlap between lesions. Grading is further complicated by the requirement to integrate multiple subjective and ill-defined parameters. On the opposite end of the histologic spectrum, malignant phyllodes tumors must be distinguished from more common metaplastic carcinomas and from primary or metastatic sarcomas, which can be especially difficult in core biopsies. Immunohistochemistry can be useful in the differential diagnosis but should be interpreted with attention to caveats. This review provides an overview and update on the spectrum of fibroepithelial lesions, with special emphasis on common problems and practical issues in diagnosis.

Combination of shear-wave elastography and color Doppler: Feasible method to avoid unnecessary breast excision of fibroepithelial lesions diagnosed by core needle biopsy

Background

We evaluated shear-wave elastography (SWE) and color Doppler ultrasonography (US) features for fibroepithelial lesions (FELs), and to evaluate their utility to differentiate fibroadenomas (FAs) and phyllodes tumors (PTs).

Methods

This retrospective study included 67 FELs pathologically confirmed (49 FAs, 18 PTs). B-mode US, SWE and color Doppler US were performed for each lesion. Mean elasticity (E_mean), maximum elasticity (E_max), and vascularity were determined by SWE and Doppler US. Diagnostic performances were calculated to differentiate FAs and PTs. Equivocal FELs diagnosed by core needle biopsy (CNB) were further analyzed.

Results

Median E_mean and E_max were significantly lower for FAs than PTs (E_mean, 15.7 vs. 66.7 kPa; E_max, 21.0 vs. 76.7 kPa, P<0.01). Low vascularity (0–1 vessel flow) on color Doppler US were more frequent in FAs than in PTs (P<0.01). SWE showed significantly higher specificities (E_mean >43.9 kPa, 89.8%; E_max >46.1 kPa, 79.6%) than B-mode US (42.9%) (P<0.01) for differentiating PTs from FAs. Other diagnostic values of SWE and overall diagnostic values of Doppler US were not significantly different from B-mode US (P>0.05). The combination of SWE and Doppler US with ‘E_mean>43.9 kPa or high vascularity (≥2 vessel flows)’ showed a higher area under the curve (0.786 vs. 0.687) and higher diagnostic values than B-mode US (sensitivity, 100 vs. 94.4%; specificity, 57.1 vs. 42.9%; positive predictive value, 46.2 vs. 37.8%; negative predictive value, 100 vs. 95.5%), without statistical significance (P>0.05). Of the 30 equivocal FELs, all lesions with ‘E_mean≤43.9 kPa and low vascularity (0–1 vessel flow)’ (23.3%, 7/30) were finally confirmed as FAs by excision.

Conclusion

FAs have a tendency to have less stiffness and lower vascularity than PTs. Combined SWE and color Doppler US may help patients with equivocal FELs diagnosed by CNB avoid unnecessary excision.

Phyllodes Tumor of the Breast: Histopathologic Features, Differential Diagnosis, and Molecular/Genetic Updates

CONTEXT

-Phyllodes tumor (PT) of the breast is a rare fibroepithelial neoplasm with risks of local recurrence and uncommon metastases. The classification proposed by the World Health Organization for PTs into benign, borderline, and malignant is based on a combination of several histologic features. The differential diagnosis between PT and fibroadenoma and the histologic grading of PT remain challenging. In addition, the molecular pathogenesis of PT is largely unknown.

OBJECTIVE

-To provide an updated overview of pathologic features, diagnostic terminology, and molecular alterations of PT.

DATA SOURCES

-Current English literature related to PT of the breast.

CONCLUSIONS

-Phyllodes tumor shows a wide spectrum of morphology. There are no clearly distinct boundaries between PT and fibroadenoma. Strict histologic assessment of a combination of histologic features with classification can help to achieve the correct diagnosis and provide useful clinical information. The genomic landscapes of PT generated from genomic sequencing provide insights into the molecular pathogenesis of PT and help to improve diagnostic accuracy and identify potential drug targets in malignant PT.

Contemporary indications for diagnostic open biopsy in women assessed for screen-detected breast lesions: A ten-year, single institution series of 814 consecutive cases

PURPOSE

In contemporary practice, 5% of women with non-malignant needle biopsies of screen-detected lesions still require diagnostic open biopsy (OBx). Our aims are to (i) capture a snapshot of the contemporary indications for OBx in screen-detected lesions; (ii) determine upgrade rates to malignancy (DCIS or invasive cancer); (iii) identify indications with sufficiently low upgrades to justify avoidance of OBx and (iv) propose plausible non-surgical alternatives.

METHODS

Between Jan 2005 and Dec 2014, women assessed for a screen-detected lesion and recommended for OBx are included. We retrieved patient, imaging, biopsy and final pathology or follow-up data.

RESULTS

814 lesions, mean diameter 16.7 mm, microcalcifications in 353 (43.4%) cases, lesions other than calcifications in 461 (56.6%), mean patient age 58.4 yrs, are included. Surgery was performed in 98.2% cases. Imaging follow-up (1-6.5 yrs) is available in 13 of 15 remaining cases. 27 indications for OBx were identified, with a prevalence of 0.3-13.9%. Borderline lesions (BL) comprised 64% of OBx indications, amongst which atypical ductal hyperplasia was the most prevalent at 13.9%, followed by papillary lesions, radial scars, flat epithelial atypia and lobular neoplasia. Imaging factors contributed 26.3% of OBx. In 9.8% of cases, NCB was not performed due to client, technical or cytologic factors. Overall, 261(32.1%) lesions were malignant at OBx. Upgrade rates varied from 0 to 100%, depending on the specific indication for OBx.

CONCLUSIONS

Surgical biopsy remains a valuable method of last resort for breast cancer diagnosis but strategies to limit benign breast surgery merit attention as a public health issue.

Diagnostic performance of core needle biopsy in identifying breast phyllodes tumors

BACKGROUND

A retrospective analysis of diagnoses was performed in patients with phyllodes tumors of the breast (PTB) who received preoperative core needle biopsy (CNB) and had breast surgery at Fudan University Shanghai Cancer Center from January 1, 2002 to April 1, 2013. The resulting data allowed us to compare the accordance between CNB and excision diagnoses of PTB patients and evaluate the accuracy of CNB in preoperative diagnosis.

METHODS

Data from 128 patients with PTB who had undergone preoperative CNB and breast surgery were retrospectively analyzed. We reviewed the medical history, clinical follow-up data, and CNB diagnostic data. A diagnostic test was used to evaluate the sensitivity and specificity of CNB in diagnosing benign, borderline, and malignant phyllodes tumors.

RESULTS

The accuracy of CNB for diagnosing PTB was 13.3% (17/128). Of the remaining patients, 98 (75.5% of the PTB patients) were diagnosed with fibroadenoma or fibroepithelial lesions. The sensitivity of CNB at diagnosing benign, borderline, and malignant phyllodes tumors were 4.9% (2/41), 4.2% (3/71), and 25.0% (4/16), respectively, whereas the corresponding specificity were 92.0%, 98.2%, and 100%, respectively. Some clinical features, such as large tumor size, rapid growth, or surgical history of fibroadenomas, were indicative of an increased possibility of PTB.

CONCLUSIONS

CNB provides a pathological basis for the preoperative diagnosis of PTB, but it has a poor accuracy and offers limited guidance for surgical decisions. Considering CNB along with multiple histologic features may improve the ability to accurately diagnose PTB. An integrated assessment using CNBs in combination with clinical data and imaging features is suggested as a reliable strategy to assist PTB diagnosis.

Phyllodes tumors of the breast: diagnosis, treatment and prognostic factors related to recurrence

Phyllodes tumors of the breast are rare tumor types that consist of 0.3-1.0% in all breast tumors. The naming and classification of breast phyllodes tumor have been debated for years. Based on the classification criteria modified by WHO in 2003, this review mainly introduced the clinicopathologic characteristics, pre-operational diagnosis and the treatment of breast phyllodes tumors, and also summarized the prognostic factors related to tumor recurrence.

A Giant Phyllodes Tumor of the Breast

Phyllodes tumors of the breast are rare, accounting for less than 1% of the breast tumors. They are mostly seen in women between 45 and 49 years old. These are fast growing tumors with a large spectrum of behavior (from benign to metastatic) and can resemble fibroadenomas. Correct diagnosis mostly through core needle biopsy is important to decide whether a surgical excision has to be done. Here we report a case of a 57-year-old woman with a fast growing, ulcerated tumor in the left breast. Core needle biopsy suggested a malignant phyllodes tumor with heterologous liposarcomatous differentiation. Treatment with total mastectomy and adjuvant radiotherapy followed. Primary treatment is always surgery, whether radiotherapy or chemotherapy has to follow remains uncertain. There is a high-recurrence rate, especially when the surgical margins are narrow.

Differentiation between Phyllodes Tumors and Fibroadenomas Based on Mammographic Sonographic and MRI Features

BACKGROUND

This study was performed to compare the mammographic, sonographic, and magnetic resonance imaging (MRI) characteristics of phyllodes tumors and fibroadenomas, which may resemble each other.

METHODS

Preoperative mammograms, B-mode and Doppler sonograms, and dynamic breast MRIs of 72 patients with pathologically proven fibroadenomas and 70 patients with pathologically proven phyllodes tumor were evaluated in this retrospective study. Statistical significance was evaluated using chi-square and Fisher's exact tests. Correlations in lesion size among radiological methods were examined by Pearson's correlation analysis.

RESULTS

The features that differed on mammogram were size, shape, and margin of the mass. Sonograms showed significant differences in size, shape, margin, echo pattern, and vascularization of the mass. Pearson's correlation analysis showed strong agreement among radiological methods in terms of assessment of size. Tumor size ≥ 3 cm, irregular shape, microlobulated margins, complex internal echo pattern, and hypervascularity were significant findings of phyllodes tumors. Internal cystic areas on MRI were frequently associated with phyllodes tumors.

CONCLUSION

Mammographic, sonographic, and MRI findings of fibroadenomas and phyllodes tumors could help radiologists to ascertain imaging-histological concordance and guide clinicians in their decision making regarding adequate follow-up or the necessity of biopsy.

A five-gene reverse transcription-PCR assay for pre-operative classification of breast fibroepithelial lesions

Background

Breast fibroepithelial lesions are biphasic tumors and include fibroadenomas and phyllodes tumors. Preoperative distinction between fibroadenomas and phyllodes tumors is pivotal to clinical management. Fibroadenomas are clinically benign while phyllodes tumors are more unpredictable in biological behavior, with potential for recurrence. Differentiating the tumors may be challenging when they have overlapping clinical and histological features especially on core biopsies. Current molecular and immunohistochemical techniques have a limited role in the diagnosis of breast fibroepithelial lesions. We aimed to develop a practical molecular test to aid in distinguishing fibroadenomas from phyllodes tumors in the pre-operative setting.

Methods

We profiled the transcriptome of a training set of 48 formalin-fixed, paraffin-embedded fibroadenomas and phyllodes tumors and further designed 43 quantitative polymerase chain reaction (qPCR) assays to verify differentially expressed genes. Using machine learning to build predictive regression models, we selected a five-gene transcript set (ABCA8, APOD, CCL19, FN1, and PRAME) to discriminate between fibroadenomas and phyllodes tumors. We validated our assay in an independent cohort of 230 core biopsies obtained pre-operatively.

Results

Overall, the assay accurately classified 92.6 % of the samples (AUC = 0.948, 95 % CI 0.913–0.983, p = 2.51E-19), with a sensitivity of 82.9 % and specificity of 94.7 %.

Conclusions

We provide a robust assay for classifying breast fibroepithelial lesions into fibroadenomas and phyllodes tumors, which could be a valuable tool in assisting pathologists in differential diagnosis of breast fibroepithelial lesions.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0692-6) contains supplementary material, which is available to authorized users.