Fibroepithelial lesions with cellular stroma on breast core needle biopsy: are there predictors of outcome on surgical excision?

Accuracy and Comparison of Core Needle Biopsy Diagnoses With Excision Specimen for Diagnosing Fibroepithelial Lesions of the Breast

Background Core needle biopsy (CNB) for fibroepithelial lesions (FELs) of the breast is commonly encountered by histopathologists. The distinction between fibroadenoma (FA) and phyllodes tumor (PT) can be challenging due to overlapping histological features and the limited nature of CNB material.  Objective This study aimed to assess the accuracy of CNB diagnosis of FA and PT by comparing it with a diagnosis on subsequent surgical excision specimen. Materials and methods A total of 166 cases of FELs of the breast who underwent CNB and subsequent surgical excision between January 2001 and December 2020 were included in our study. All microscopy glass slides were reviewed, and diagnosis confirmed. Results While 125 (75%) cases based on CNB received a definitive diagnosis of either fibroadenoma or PT, the remaining 41 (25%) cases were better classified on excision specimens and were descriptively diagnosed as fibroepithelial lesions on CNB. Diagnoses on CNB and on subsequent excision specimens were concordant in 113 (90.4%) cases. Among 12 cases that were discordant, three cases diagnosed as FA on CNB were upgraded to PT on excision specimens. Nine cases diagnosed as PT on CNB were diagnosed as FA on excision specimens. These included conventional, cellular, juvenile, and complex FA types. Three PTs, which were reported as FA on CNB, measured 6, 12.5, and 17.5 cm in the greatest dimension. Among 23 cases of PT which were further categorized on CNB, tumor categories changed on excision specimens in three cases. The diagnostic accuracy of CNB diagnosis was 90.4%. Conclusion CNB diagnosis showed good accuracy. PT diagnosis should be strongly considered in all tumors measuring >5 cm, especially those exceeding 10 cm. Cellular, juvenile, and complex FAs can be misdiagnosed as PT on CNB. Correlation with clinical and radiological findings can be helpful in establishing correct diagnosis.

Challenges and Clinical Relevance of Modern Breast Pathology Reporting: Your Questions Answered

BACKGROUND

Breast pathology reporting, especially for breast cancer, has evolved through the years, from terse succinct diagnostic conclusions with scant histological details to the current comprehensive reporting guidelines issued by major pathology colleges and bodies, including the International Collaboration on Cancer Reporting. Pathology elements included in reporting guidelines are evidence based and contribute significantly to individualised and personalised patient management.

SUMMARY

This article is based on the lively interactive question and answer session that followed the breast pathology segment in the symposium jointly organised by the British Association of Urological Pathology, British Association of Gynaecological Pathologists, British Society of Gastroenterology and the Association of Breast Pathology, in November 2022, titled "Personalised histopathology reporting for personalised medicine."

KEY MESSAGES

The breast pathology session emphasised the clinical utility of breast pathology data items, incorporating a case-based approach by highlighting the relevance of pathology information in various clinical scenarios. This review included clinico-pathological discussion points on florid lobular carcinoma in situ, atypical apocrine adenosis, post-neoadjuvant chemotherapy reporting, atypical ductal hyperplasia presenting at the margin, flat epithelial atypia versus columnar cell change, papilloma on core needle biopsy, margin status, mucocele-like lesion, total duct excision/microdochectomy specimen, and anterior and nipple margins in skin-sparing mastectomy. Effective communication and regular involvement of pathologists in breast multidisciplinary tumour boards are crucial.

Diagnosis on Excision Biopsy of Breast Tissues Labeled As Fibroepithelial Tumors on Trucut Samples in a Developing Country

Introduction: Fibroadenomas (FAs) and phyllodes tumors (PTs) are less prevalent but allied to have malignant transformation in many instances. It is a challenge to diagnose the phyllodes by conventional trucut biopsy technique.

Objective: To evaluate the histological characteristics of tumors labeled as fibroepithelial lesions of breast tissues on trucut biopsy and compare with a diagnosis on excision biopsy.

Methods and materials: It was a descriptive cross-sectional study that was carried out in Shaukat Khanum Memorial Hospital and Research Centre within six years from January 2015 to January 2021. In trucut samples, stromal cellularity, stromal cell nuclear atypia, mitotic count, stromal overgrowth, the enhancement of stromal cellularity adjacent to epithelium were scrutinized. In each category, the activity was seen as absent, mild, moderate, or severe. Mitotic activity was graded as 0-1, 0-5, 5-10, >10.

Results: A total of 125 patients were registered for the study. The mean age of patients in our study was 33.86 ± 9.95 years. The mean size was 41.02 ± 27.38 mm with a mean lump duration of 7.52 ± 5.34 months. In the FA group, the trucut sampling report showed the stromal cellularity as mild in 62 (69.7%) and stromal cell nuclear atypia as absent in 68 (76.4%) cases. But in the phyllodes tumor group, the stromal cellularity was severe in 10 (27.8%) patients and stromal cell nuclear atypia was severe in five (13.9%). The ultimate outcome showed that 89 (71.2%) patients had FA and 36 (28.8%) had PT at excision.

Conclusion: Assessment of tumor size, stromal cellularity, mitoses, and enhancement of stromal cellularity adjacent to epithelium are useful markers for diagnosing the PT in trucut needle biopsy.

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.

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.

Utility of Trucut Biopsy in Diagnosing Phyllodes Tumor

Breast phyllodes are rare fibroepithelial neoplasms. Various classifications adopted to grade them into benign, borderline and malignant but the presently used one is the WHO classification of 2012. Trucut biopsy is a sensitive prediagnostic tool to grade phyllodes. But features can sometimes be overlapping making it difficult to grade it. In this study, an effort has been made to compare the morphology of trucut and histolopathology specimens. Sensitivity of the trucut bopsy in diagnosing benign and malignant phyllodes is calculated and is being compared with other studies. Hence due to varied morphological features sole diagnosis should not be based on trucut biopsy.

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: Analysis of 48 Patients

OBJECTIVE

Phyllodes tumor (PT) is a rare biphasic breast neoplasm that accounts for less than 1% of all breast tumors. The aim of this study was to evaluate the clinicopathologic features, diagnostic difficulties, and therapeutic outcomes of patients with PT.

MATERIALS AND METHODS

A total of 48 female patients who underwent surgery for PT were included in the study. Patient characteristics, clinicopathologic features of tumors, diagnostic findings, surgical outcomes, adjuvant therapies, and follow-up findings were retrospectively evaluated.

RESULTS

The mean age of patients was 35 years. Painless breast mass was the most common (85.4%) presenting symptom. Total excision with at least 1 cm macroscopic clear margins was the most frequently performed (87.5%) surgery. Most patients (n=34, 70.8%) had benign PT; however, borderline and malignant tumors were found in 9 (18.8%) and 5 (10.4%) patients, respectively. During the mean follow-up period of approximately 30 months, local and distant recurrence was detected in three (6.3%) patients and one (2.1%) patient, respectively. Patients with malignant PT had larger tumors than those with benign and borderline PTs (p=0.010). No significant difference in other clinical, diagnostic, and pathologic characteristics was found between the groups.

CONCLUSION

PT can be easily confused with other breast masses such as fibroadenoma due to the non-specific clinical and radiologic findings. Surgical excision with at least 1 cm clear margins is of great importance to reduce the risk of local recurrence. However, recurrence can develop even after appropriate surgery, thus patients should be closely followed up after surgery.

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.

How to approach phyllodes tumors of the breast?

OBJECTIVE

Phyllodes tumor of the breast is a rare fibroepithelial breast tumor that comprise 0.3-0.9% of primary breast neoplasms. In this study, we aimed to present clinicopathologic symptoms of our patients along with their treatment modality.

MATERIAL AND METHODS

Clinicopathologic properties and treatment modality of 20 phyllodes tumor patients who underwent surgery between January 2008 and January 2013 were retrospectively evaluated.

RESULTS

Median patient age was 47 years (22-75). Fine-needle aspiration biopsy was applied to 19 patients. Biopsy results were reported as suspicious in four, malignant in three, benign in 11, and as non-diagnostic in one patient. Final histopathology reports revealed two benign, one malignant and one borderline tumor out of the four patients with suspicious findings on fine needle aspiration biopsy; all patients with malignant cytology had malignancy. There were two borderline and nine benign lesions within the benign biopsy group. Sixteen patients underwent segmental mastectomy, four patients underwent mastectomy with/without axillary dissection. The median tumor size was 6 (1-13) cm. Histopathologically, 11 (55%) tumors were benign, 5 (25%) were borderline, and 4 (20%) were malignant. Two of the four patients with malignancy underwent radiotherapy and chemotherapy, and one patient only received chemotherapy as adjuvant treatment.

CONCLUSION

Phyllodes tumors are rare, mix-type breast tumors. Due to high rates of local recurrence and potential for malignancy, preoperative diagnosis and accurate management are important.

Fibroadenoma versus phyllodes tumor: distinguishing factors in patients diagnosed with fibroepithelial lesions after a core needle biopsy

PURPOSE

We aimed to identify factors that might help differentiate phyllodes tumors from fibroadenomas among cases in which a fibroepithelial breast lesion was diagnosed from core needle biopsy (CNB) under imaging guidance.

MATERIALS AND METHODS

A retrospective review was performed on 213 lesions in 200 patients who had undergone both CNB and excisional biopsy during a four-year period between 2008 and 2011. The final pathology revealed 173 fibroadenomas and 40 phyllodes tumors. The data, including patient characteristics, clinical presentation, and mammography, ultrasonography (US), and pathology findings were analyzed.

RESULTS

Upon univariable analysis, the factors that significantly helped to identify phyllodes tumors consisted of the presenting symptoms (palpable mass or breast pain), increased size on clinical examination, hyperdense mass on mammogram, and the following three US features: heterogeneous echo, presence of round cysts within the mass, and presence of clefts within the mass. The pathologist's suggestion of a phyllodes tumor was also helpful. The factors that remained statistically significant upon multivariable analysis consisted of symptoms of breast pain, the presence of clefts on US, the presence of round cysts on US and the pathologist's favoring of phyllodes tumors from a CNB specimen.

CONCLUSION

A multidisciplinary approach was needed to distinguish phyllodes tumors from fibroadenomas in patients who had undergone CNB. US findings (clefts and round cysts), suggestive pathological diagnoses, and clinical symptoms were all useful for the decision to surgically remove the fibroepithelial lesions diagnosed from CNB.

Significant histologic features differentiating cellular fibroadenoma from phyllodes tumor on core needle biopsy specimens

OBJECTIVES

Cellular fibroepithelial lesions (CFELs) are a heterogeneous group of tumors encompassing cellular fibroadenoma (CFA) and phyllodes tumor (PT). Distinction between the two is challenging on core needle biopsy (CNB) specimens. The objective of this study was to evaluate histologic features that can help distinguish PT from CFA on CNB specimens.

METHODS

Records of all patients diagnosed with CFELs on CNB specimens with follow-up excision between January 2002 and December 2012 were retrieved. Histopathologic stromal features were evaluated on CNB specimens, including mitoses per 10 high-power fields (hpf), overgrowth, increased cellularity, fragmentation, adipose tissue infiltration, heterogeneity, subepithelial condensation, and nuclear pleomorphism.

RESULTS

Twenty-seven (42.2%) of 64 were diagnosed as PT (24 benign PTs and three borderline PTs) and 37 (57.8%) as CFA on excision. All features except for increased stromal cellularity were statistically significant. The average number of histologic features seen in PT and CFA was 3.9 and 1.4, respectively (odds ratio [OR], 7.27; 95% confidence interval [CI], 2.44-21.69; P = .0004). The average number of mitoses per 10 hpf was 3.0 for PT compared with 0.8 for CFA (OR, 2.14; 95% CI, 1.18-3.86; P = .01).

CONCLUSIONS

The presence of mitoses (three or more) and/or total histologic features of three or more on CNB specimens were the most helpful features in predicting PT on excision.

Ultrasonic elastography features of phyllodes tumors of the breast: a clinical research

The purpose of this study was to analyze the ultrasonic elastography features of phyllodes tumors of the breast comparing with fibroadenomas. A retrospective database was queried for the patients diagnosed as phyllodes tumors and fibroadenomas at Sun Yat-sen Memorial Hospital from January 2008 to August 2012. Three hundred and fifty lesions from 323 consecutive patients were included in the study. All the cases were examined by conventional ultrasonography and ultrasound elastography. Ultrasound elastography was used to calculate strain ratio of the lesions with bilateral breast tissue at the same depth as reference. There were 36 phyllodes tumors (27 benign, 8 borderline, 1 malignant) and 314 fibroadenomas (158 the pericanalicular type, 103 the intracanalicular type, 53 other special types). The strain ratio for phyllodes tumors (3.19±2.33) was significantly higher than for fibroadenomas (1.69±0.88) (p<0.05). The Spearman^.s correlation coefficient between strain ratio of ultrasound elastography and pathological groups was significant, with a value of 0.17 (p<0.05). Ultrasound elastography could provide additional information to differentiate phyllodes tumors from fibroadenoma in breast.

Phyllodes tumor of breast: a review article

Introduction. Phyllodes tumours are rare fibroepithelial lesions. Accurate preoperative pathological diagnosis allows correct surgical planning and avoidance of reoperation. Treatment can be either wide local excision or mastectomy to achieve histologically clear margins. Discussion. The exact aetiology of phyllodes tumour and its relationship with fibroadenoma are unclear. Women aged between 35 and 55 years are commonly involved. The median tumour size is 4 cm but can grow even larger having dilated veins and a blue discoloration over skin. Palpable axillary lymphadenopathy can be identified in up to 10-15% of patients but <1% had pathological positive nodes. Mammography and ultrasonography are main imaging modalities. Cytologically the presence of both epithelial and stromal elements supports the diagnosis. The value of FNAC in diagnosis of phyllodes tumour remains controversial, but core needle biopsy has high sensitivity and negative predictive value. Surgical management is the mainstay and local recurrence in phyllodes tumours has been associated with inadequate local excision. The role of adjuvant radiotherapy and chemotherapy remains uncertain and use of hormonal therapy has not been fully investigated. Conclusion. The preoperative diagnosis and proper management are crucial in phyllodes tumours because of their tendency to recur and malignant potential in some of these tumours.