Comparative study of histological features between core needle biopsy and surgical excision in phyllodes tumor

De-escalating indications for excision when breast core needle biopsy returns fibroepithelial lesion-not further characterized

PURPOSE

Surgical excision is often performed to exclude phyllodes tumor (PT) when Core Needle Biopsy (CNB) of the breast returns fibroepithelial lesion-not further characterized (FEL-NFC). If imaging or CNB pathology features can be identified that predict a very low probability of borderline/malignant PT, thousands of women could be spared the expense and morbidity of surgical excisions.

METHODS

This retrospective cohort study includes 180 FEL-NFC from 164 patients who underwent surgical excisional biopsy.

RESULTS

The upgrade rate from FEL-NFC to benign PT was 15%, and to borderline/malignant PT 7%. Imaging features predicting upgrade to borderline/malignant PT included greater size (p = 0.0002) and heterogeneous echo pattern on sonography (p = 0.117). Histologic features of CNB predicting upgrade to borderline/malignant PT included "pathologist favors PT" (p = 0.012), mitoses (p = 0.014), stromal overgrowth (p = 0.006), increased cellularity (p = 0.0001) and leaf-like architecture (p = 0.077). A three-component score including size > 4.5 cm (Size), heterogeneous echo pattern on sonography (Heterogeneity), and stromal overgrowth on CNB (Overgrowth) maximized the product of sensitivity x specificity for the prediction of borderline/malignant PT. When the SHO score was 0 (72% of FEL-NFC) the probability of borderline/malignant PT on excision was only 1%.

CONCLUSION

The combination of size ≤ 4.5 cm, homogeneous echo pattern, and absence of stromal overgrowth is highly predictive of a benign excision potentially sparing most patients diagnosed with FEL-NFC the expense and morbidity of a surgical excision.

Fibroepithelial Lesion Spectrum: A Case Report Documenting a Possible Transformation to a Malignant Phyllodes Tumor

We discuss the radiological-pathological aspects of a rare case of transformation of a presumed fibroadenoma (FA) to a malignant phyllodes tumor (PT) and review the literature. Phyllodes tumors often show heterogeneous histologic features with some areas indistinguishable on core needle biopsy. A core biopsy is often a small representation of a larger lesion. As such, a complete excisional biopsy is often needed for a definitive pathologic diagnosis. Careful clinical and imaging correlation and follow-up are necessary, even in a benign fibroepithelial lesion (FEL).

Margin Status and Local Recurrence in Phyllodes Tumours of the Breast: A Canadian Series

BACKGROUND

Phyllodes tumours of the breast are rare fibroepithelial neoplasms with a propensity for recurrence. While surgical excision remains the standard of care, the optimal margin width is an area of active investigation. Recent studies have questioned the necessity for wide, local excision.

METHODS

We conducted a retrospective, cohort study of patients with phyllodes tumours treated at our institution between 2003 and 2021. Demographic, histopathological, and recurrence data were captured; malignant phyllodes were excluded. Cox proportional hazard models were used to identify covariates associated with local recurrence.

RESULTS

Of 187 patients with phyllodes tumours, 82.9% (n = 155) were classified as benign while 17.1% (n = 32) were borderline. Initial surgical margins were positive in 26.2% (n = 49), < 2 mm in 50.8% (n = 95), and ≥ 2 mm in 23% (n = 43) patients. Among patients with positive margins, 61.2% (n = 30) underwent margin revision. At a median follow-up of 2.9 years, the recurrence rate was 3.7%. On univariate analysis, only a positive margin at the time of initial surgery and not margin width was significantly associated with a higher rate of disease recurrence (hazard ratio [HR] 9.52, 95% confidence interval [CI] 1.85-49.2), as was a size greater than 4 cm on preoperative imaging (HR 10.78, 95% CI 0.97-120.1). Revision of an initially positive margin was not significantly associated with decreased local recurrence (p = 1).

CONCLUSIONS

In this large cohort of benign and borderline phyllodes tumours, positive resection margins and not margin width at the initial surgery were associated with a increased recurrence. Individualization of decisions regarding margin reexcision is important.

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.

Malignant phyllodes tumor of the breast: a systematic review

Phyllodes tumors (PT) are fibroepithelial neoplasms of the breast showing a peculiar leaf-like appearance. They account for 0.3 to 1% of all primary breast tumors and 2.5% of all fibroepithelial breast tumors. PT are classified into benign, borderline and malignant based upon their stromal morphology with a distribution of 60%, 20%, and 20%, respectively. Malignant PT of the breast constitute an uncommon challenging group of fibroepithelial neoplasms. They have a relatively high tendency to recur, although distant metastasis is uncommon, and nearly exclusive to malignant PT. Adequate surgical resection remains the standard approach to achieve maximal local control. Giant malignant PT are rare and a pose a diagnostic dilemma for pathologists, especially when comprised of sarcomatous elements. This review highlights the morphological features of PT detected in cytology and histology specimens and discusses diagnostic pitfalls and differential diagnosis.

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.

Diagnosis and management of phyllodes tumours for the surgeon: An algorithm

A Phyllodes Tumour (PT) is an uncommon fibroepithelial lesion, with three histological grades - benign, borderline and malignant. PTs cause significant challenges in diagnosis, management and prognostication. Recent publications have clarified the definitions and prognostication of PTs. Contemporary data currently challenge international guidelines on PT management. We performed an in-depth literature review to develop a best-practice management algorithm for PTs. Diagnostic recommendations are that neither current imaging techniques, nor fine-needle biopsies, can reliably diagnose a PT. Core needle biopsy is the optimal diagnostic technique. Indeterminate or suspicious lesions are recommended to undergo an excisional biopsy due to the inherently heterogeneous nature of PTs. Management guidelines are that benign PTs should be completely excised, although an involved margin is acceptable in select situations. Borderline PTs should have a clear margin on excision due to their higher risk of recurrence, as well as the potential for a recurrence to progress to a malignant PT. In malignant PTs, a margin of 3 mm is acceptable as there is no reduction in recurrence risk if margins are >3 mm. Routine axillary surgery is not indicated in PTs, with axillary surgery only indicated in a histologically-confirmed positive axilla. Adjuvant treatment recommendations are that borderline and malignant PTs should be discussed at MDT, with radiotherapy considered in both. Chemotherapy should be discussed in malignant PT patients. In summary, we have developed an up-to-date simple algorithm to guide the surgeon's management of patients diagnosed with PTs and reduce excessive surgery.

Phyllodes Tumors: A Scoping Review of the Literature

PURPOSE

Phyllodes tumors are rare tumors of the breast, with most literature being retrospective with limited guidelines on the management of these patients. Scoping review was performed to highlight themes and gaps in the available literature.

METHODS

A scoping review of the literature was performed as per PRISMA-ScR guidelines with titles, abstracts, and full texts reviewed in duplicate. Data were abstracted and summarized in categories of diagnostics, surgical management, adjuvant therapies, treatment of recurrence, and surveillance. Quality assessment was performed for each paper.

RESULTS

The search identified 4498 references, 434 full-text papers were reviewed, and 183 papers were included. Ultrasound, magnetic resonance imaging, and core needle biopsy are valuable preoperative diagnostics tools. Pathology reporting should include stromal overgrowth, stromal cellularity, nuclear atypia, mitotic rate, borders, and presence of heterologous elements. Ki67 may have a role in grading and prognosticating. Breast conservation is safe in all grades of phyllodes but may be associated with increased local recurrence in malignant phyllodes. Surgical margins should depend on grade. Axillary node positivity rate is very low, even with clinically enlarged lymph nodes. Adjuvant radiation is a useful tool to decrease local recurrence in malignant phyllodes tumors, tumors > 5 cm, age < 45 years, close margins, and breast conservation. There is no evidence supporting adjuvant chemotherapy. Recurrence can be managed with repeat wide excision; however, mastectomy is associated with lower re-recurrence. Surveillance protocols are variable in the literature.

CONCLUSIONS

There is heterogeneity in the literature on phyllodes tumors. Consensus guidelines based on the literature will help provide evidence-based care.

High-risk lesions of the breast: concurrent diagnostic tools and management recommendations

Breast lesions with uncertain malignant behavior, also known as high-risk or B3 lesions, are composed of a variety of pathologies with differing risks of associated malignancy. While open excision was previously preferred to manage all high-risk lesions, tailored management has been increasingly favored to reduce overtreatment and spare patients from unnecessary anxiety or high healthcare costs associated with surgical excision. The purpose of this work is to provide the reader with an accurate overview focused on the main high-risk lesions of the breast: atypical intraductal epithelial proliferation (atypical ductal hyperplasia), lobular neoplasia (including the subcategories lobular carcinoma in situ and atypical lobular hyperplasia), flat epithelial atypia, radial scar and papillary lesions, and phyllodes tumor. Beyond merely presenting the radiological aspects of these lesions and the recent literature, information about their potential upgrade rates is discussed in order to provide a useful guide for appropriate clinical management while avoiding the risks of unnecessary surgical intervention (overtreatment).

Accuracy of Breast Fine-Needle Aspiration Biopsy Using the International Academy of Cytology Yokohama System in Clinico-Radiologically Indeterminate Lesions: Initial Findings Demonstrating Value in Lesions of Low Suspicion of Malignancy

BACKGROUND

Fine-needle aspiration biopsy (FNAB) in breast lesions offers accurate results in differentiating benign and malignant lesions. However, its role is unclear when core-needle biopsy (CNB) is available, the latter providing additional information regarding tumor grade, invasion, and hormone receptor status in malignant lesions. In benign breast lesions, especially in BIRADS category 4a and 4b, FNAB, and CNB provide similar pathological information, whereby FNAB may serve as a more rapid and cost-effective investigation. The study was planned to reevaluate the diagnostic accuracy of FNAB in BIRADS category 4a, 4b, and 4c lesions.

MATERIALS AND METHODS

FNAB and biopsy reports of all patients with breast lesions sent between September 1, 2018, and November 30, 2020, were collected and the International Academy of Cytology (IAC) Yokohama category and BIRADS score were recorded for each case. The rate of malignancy and the accuracy of FNAB in diagnosing malignancy were calculated for each BIRADS 4a, 4b, and 4c subgroup.

RESULTS

A total of 249 cases of BIRADS 4 lesions had corresponding cytology and histopathology diagnoses. FNAB showed high diagnostic accuracy in all BIRADS groups. A benign categorization was associated with a very low number of false-negative diagnoses, especially in BIRADS 4a lesions.

CONCLUSION

The study reconfirms the excellent accuracy of breast FNAB using the IAC Yokohama system in diagnosing breast malignancies. Furthermore, BIRADS 4a lesions found to be belonging to the cytological benign category may be excluded from CRB and kept on clinical follow-up.

Fibroepithelial Lesion Initially Believed to Be Fibroadenoma, but Interval Growth Consistent With Phyllodes Tumor

Fibroepithelial lesions of the breast are commonly encountered tumors comprised of stromal and epithelial components. Fibroadenoma and phyllodes tumor are both fibroepithelial lesions, but their management differs. Phyllodes tumor requires surgical excision, whereas fibroadenoma requires no further workup. Both have many overlapping histological features making it difficult to distinguish between a benign fibroadenoma versus the more aggressive phyllodes tumor. This case details a breast mass that was initially believed to be a fibroadenoma, but interval growth at one year follow up resulted in surgical excision with final pathology revealing phyllodes tumor.

Re-excision or "wait and watch"-a prediction model in breast phyllodes tumors after surgery

Background

The prognosis of breast phyllodes tumors (PTs) largely depending on the pathological grading, which lacks objectivity. This study aimed to develop a nomogram based on clinicopathological features to evaluate the recurrence probability of PTs following surgery.

Methods

Data from 334 patients with breast PTs, who underwent surgical treatment at Sun Yat-sen Memorial Hospital from January 2005 to December 2014, were used to develop a prediction model. Additionally, data of 36 patients from Peking University Shenzhen Hospital (cohort 1) and data of 140 patients from Sun Yat-sen University Cancer Center (cohort 2) during the same period were used to validate the model. The medical records and tumor slides were retrospectively reviewed. The log-rank and Cox regression tests were used to develop a clinical prediction model of breast PTs. All statistical analyses were performed using R and STATA.

Results

Of all 334 patients included in the primary cohort, 224 had benign, 91 had borderline, and 19 had malignant tumors. The 1-, 3-, and 5-year recurrence-free survival was 98.5%, 97.9%, and 96.8%, respectively. Ultrasound-guided vacuum-assisted biopsy (UGVAB) is a non-inferior treatment application in benign PTs compared with open surgery [hazard ratio (HR), 2.38; 95% confidence interval (CI), 0.59–9.58]. Width of surgical margin, mitoses, and tumor border were identified as independent risk factors for breast PTs. A nomogram was developed based on these three variables. The C-index of internal and external validation was 0.71, 0.67 (cohort 1) and 0.73 (cohort 2), respectively.

Conclusions

The study model presented more concise and objective variables to evaluate the recurrence-free survival of patients after surgery, which can help deciding whether to do a re-excision or “wait and watch”.

Mammary mesenchymal and fibroepithelial lesions: An illustrated cytomorphologic update with differential diagnoses

The Uniform Approach to Breast Fine Needle Aspiration Biopsy was put forward by a learned group of breast physicians in 1997. This landmark manuscript focused predominantly on diagnosis and reporting of mammary epithelial lesions. Today, most American practitioners turn initially to core biopsy rather than aspiration biopsy for the first line diagnosis of solid breast lesions; however, recent efforts from the International Academy of Cytology have produced a system called the Standardized Reporting of Breast Fine Needle Aspiration Biopsy Cytology (colloquially labeled in 2017 as the "Yokohama System"), suggesting a new interest in breast fine needle aspiration (FNA), especially in resource limited settings or clinical practice settings with experienced breast cytopathologists. Fibroepithelial lesions of the breast comprise a heterogeneous group of biphasic tumors with epithelial and stromal elements. Mesenchymal lesions of the breast include a variety of neoplasms of fibroblastic, myofibroblastic, endothelial, neural, adipocytic, muscular, and osteo-cartilaginous derivations. The cytology of mesenchymal breast lesions is infrequently described in the literature and is mainly limited to case reports and small series. This illustrated review highlights the cytologic features of fibroepithelial and mesenchymal mammary proliferations and discusses differential diagnoses and histomorphologic correlates.

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.

Fine-needle versus core-needle biopsy - which one to choose in preoperative assessment of focal lesions in the breasts? Literature review

Aim

The aim of the study was to review two techniques that can be used to verify focal lesions in the breasts: fine-needle aspiration biopsy and core-needle biopsy.

Material and methods

Fifty-five articles (original papers and reviews), half of them published within the past 5 years, were included in the analysis. The authors also took their own experience into account.

Results

Pre-operative assessment of focal lesions in the breasts is crucial in the planning of further therapeutic management. The role of fine-needle aspiration biopsy has been reduced lately due to its low sensitivity and specificity as well as a high rate of non-diagnostic, suspicious and false negative results. This method does not enable one to differentiate between in situ and invasive disease. Currently, fine-needle biopsy is recommended for cystic lesions, suspected of being recurrences in the chest wall, and lymph node metastases. Core-needle biopsy is the basic diagnostic method of breast lesions. According to the recommendations of the Polish Ultrasound Society and American College of Radiology, BIRADS 4 and 5 lesions should be evaluated histopathologically. Core-needle biopsy makes it possible to establish a final diagnosis more frequently than fine-needle biopsy, both in the case of benign and malignant lesions. It delivers more information about the nature of a tumor (mutation of HER-2, estrogen and progesterone receptors and Ki-67 index). Its limitations include: underestimation of invasion and failure to recognize the components of ductal carcinoma in situ in papillary and atypical lesions. Single fine-needle aspiration biopsy is inexpensive, but when considering the cost of further diagnosis due to non-diagnostic, suspicious and atypical results, this method generates high additional costs.

Conclusions

Microscopic verification of focal breast lesions is crucial for further therapeutic decisions. It has been proven that histopathological verification is more accurate and has more advantages than cytological assessment.

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.

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.

First International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions)

The purpose of this study is to obtain a consensus for the therapy of B3 lesions. The first International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions) including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL), benign phyllodes tumors (PT), and radial scars (RS) took place in January 2016 in Zurich, Switzerland organized by the International Breast Ultrasound School and the Swiss Minimally Invasive Breast Biopsy group-a subgroup of the Swiss Society of Senology. Consensus recommendations for the management and follow-up surveillance of these B3 lesions were developed and areas of research priorities were identified. The consensus recommendation for FEA, LN, PL, and RS diagnosed on core needle biopsy or vacuum-assisted biopsy (VAB) is to therapeutically excise the lesion seen on imaging by VAB and no longer by open surgery, with follow-up surveillance imaging for 5 years. The consensus recommendation for ADH and PT is, with some exceptions, therapeutic first-line open surgical excision. Minimally invasive management of selected B3 lesions with therapeutic VAB is acceptable as an alternative to first-line surgical excision.

Phyllodes tumours of the breast: a consensus review

Phyllodes tumours constitute an uncommon but complex group of mammary fibroepithelial lesions. Accurate and reproducible grading of these tumours has long been challenging, owing to the need to assess multiple stratified histological parameters, which may be weighted differently by individual pathologists. Distinction of benign phyllodes tumours from cellular fibroadenomas is fraught with difficulty, due to overlapping microscopic features. Similarly, separation of the malignant phyllodes tumour from spindle cell metaplastic carcinoma and primary breast sarcoma can be problematic. Phyllodes tumours are treated by surgical excision. However, there is no consensus on the definition of an appropriate surgical margin to ensure completeness of excision and reduction of recurrence risk. Interpretive subjectivity, overlapping histological diagnostic criteria, suboptimal correlation between histological classification and clinical behaviour and the lack of robust molecular predictors of outcome make further investigation of the pathogenesis of these fascinating tumours a matter of active research. This review consolidates the current understanding of their pathobiology and clinical behaviour, and includes proposals for a rational approach to the classification and management of phyllodes tumours.

Risks of Being Malignant or High Risk and Their Characteristics in Breast Lesions 20 mm or Larger After Benign Results on Ultrasonography-Guided 14-Gauge Core Needle Biopsy

PURPOSE

The malignancy risk, risk of being high-risk lesions after benign results on ultrasonography-guided 14-gauge core needle biopsies (US-CNBs), and their characteristics in breast lesions of 20 mm or greater were investigated.

METHODS

Eight hundred forty-seven breast lesions with benign results on US-CNB were classified as benign, high risk, and malignant through excision and clinical follow-up. The risks of being malignant or high risk were analyzed in all lesions, lesions 20 to 29 mm, and lesions 30 mm or greater. Their clinicopathological characteristics were evaluated.

RESULTS

Of 847, 18 (2.1%) were malignant, 53 (6.3%) were high-risk lesions, and 776 (91.6%) were benign. Of 18 malignancies, 6 (33.3%) were malignant phyllodes tumors and 12 (66.7%) were carcinomas. In benign lesions 20 to 29 mm, risks of being malignant or high risk were 1.6% (9 of 566) and 4.4% (25 of 566). In 281 lesions 30 mm or greater, the risks of being malignant or high risk were 3.2% and 10%. The risk of being high risk in lesions 30 mm or greater was 10%, significantly higher than 4.4% of lesions 20 to 29 mm (P = 0.002).

CONCLUSIONS

Excision can be considered in lesions measuring 20 mm or larger because of the 2.1% malignancy risk and the 6.3% risk of being high-risk lesions despite benign results on US-CNB. Excision should be considered in lesions measuring 30 mm or larger because of the 3.2% malignancy risk and the 10% risk of being high-risk lesions.

A Single-center Experience and Review of the Literature: 64 Cases of Phyllodes Tumors to Better Understand Risk Factors and Disease Management

Phyllodes tumors of the breast are rare fibroepithelial tumors that are characterized as benign, borderline, or malignant based on cellular characteristics such as stromal overgrowth and number of mitoses. Currently, there is a lack of consensus on risk factors and management of patients with phyllodes tumors, which has led to variation in treatment patterns as well as patient outcomes across many institutions. This study seeks to understand the clinicopathologic features, risk factors for local and metastatic recurrence, and clinical outcomes of patients with phyllodes tumors to better define optimal treatment patterns.

Phyllodes tumor diagnosed after ultrasound-guided vacuum-assisted excision: should it be followed by surgical excision?

Our aim was to retrospectively evaluate the results of ultrasound (US)-guided vacuum-assisted excision (US-VAE) of phyllodes tumors (PTs). A total of 41 PTs diagnosed at US-VAE followed by surgery (n = 27) or at least 2 y of US monitoring (n = 14) were included. By comparison of US-VAE pathology with surgical histology or follow-up US results, cases were divided into upgraded (malignant) and non-upgraded (benign) groups. These two groups were compared with respect to clinical, procedural and US features. Among 27 surgical cases, 2 (8.7%) of 23 benign PTs were upgraded to malignant PTs. The Breast Imaging Reporting and Data System category was retrospectively assigned as 4a (50%) or 4b (50%) in the upgraded group (n = 2) and 3 (64%) or 4a (36%) in the non-upgraded group (n = 39) (p = 0.018). Residual tumor was observed at the site of US-VAE in 15 of 27 surgical cases and 0 of 14 US follow-up cases (36.6%, 15/41). Given the rates of upgrade to malignancy (8.7%) and residual tumor (36.6%), PTs diagnosed after US-VAE should be surgically excised.

Phyllodes tumours of the breast diagnosed as B3 category on image-guided 14-gauge core biopsy: analysis of 51 cases from a single institution and review of the literature

AIMS

Image-guided 14-gauge (G) core biopsy (CB) has been shown to be an accurate method providing histological diagnosis of breast lesions. The purpose of this study was to evaluate the reliability of image-guided 14-G CB in the diagnosis of phyllodes tumours (PT) reported as B3 category and its accuracy in distinguishing this lesion from fibroadenomas (FA).

MATERIALS AND METHODS

The records of 10 000 image-guided 14-G CB of the breast performed from January 2001 to August 2011 at the Diagnostic Senology Unit of Careggi University Hospital were reviewed; 2554 (25.5%) were fibroepithelial lesions: 56 of them (2%) were diagnosed as PT and reported as B3 category. The database of the Pathological Anatomy Unit of Careggi University Hospital was then searched to verify the histological diagnosis after surgical excision. Fifty-one cases of PT diagnosed as B3 category in 51 women were included in the present study.

RESULTS

Of the 51 cases of PT diagnosed as B3 category on 14-G CB, 39 (76.5%) lesions were confirmed as PT on SE (30, 4 and 5 as benign, borderline and malignant PT respectively) with a PPV of 76.5%. Twelve lesions (23.5%) were diagnosed as FA after surgical excision.

CONCLUSIONS

Our study shows that 14-G CB is a valuable tool, in a preoperative setting, in diagnosing PT.

Phyllodes tumors of the breast: ultrasonographic findings and diagnostic performance of ultrasound-guided core needle biopsy

We evaluated ultrasonography (US) findings between benign and malignant phyllodes tumors and analyzed diagnostic performance of US-guided core needle biopsy (CNB) for phyllodes tumors. Surgically removed phyllodes tumors of 168 women were divided into two groups according to the benign and malignant (including borderline tumor) groups and 116 were benign and 52 were malignant. On US, the complex cystic echogenicity (p = 0.021), presence of cleft (p = 0.005) and higher final US assessment (p = 0.008) were more frequent in the malignant group. The sensitivity of CNB including fibroepithelial tumors was 67.9% (114/168) and the concordant rate between CNB and surgical excision was 82.1% (32/39) and 5.8% (3/52) in the benign and malignant group. Our results suggested that the US findings of complex cystic echogenicity, cleft, higher final US assessment were more frequent in malignant phyllodes tumors. The sensitivity of CNB was 67.9% (114/168) and malignant phyllodes tumors were rarely diagnosed as malignant by US-guided CNB.