Needle core biopsy in the diagnosis of phyllodes neoplasm

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.

Excision of breast fibroepithelial lesions: when is it still necessary?-A 10-year review of a regional centre

PURPOSE

Fibroepithelial lesions (FEL) range from benign fibroadenoma (FA) to malignant phyllodes tumor (PT), but can be difficult to diagnose on core needle biopsy (CNB). This study assesses risk factors for phyllodes tumor (PT) and recurrence and whether a policy to excise FELs over 3 cm in size is justified.

METHODS

Patients having surgery for FELs from 2009 to 2018 were identified. The association of clinical, radiology and pathological features with PT and recurrence were evaluated. Trend analysis was used to assess risk of PT based on imaging size.

RESULTS

Of the 616 patients with FELs, 400 were identified as having FA on CNB and 216 were identified as having FEL with a comment of concern for phyllodes tumor (query PT, QPT). PT was identified in 107 cases; 28 had CNB of FA (7.0%), while 79 had QPT (36.6%). Follow-up was available for 86 with a mean of 56 months; six patients had recurrence of PT, all of whom had QPT on CNB. The finding of PT was associated with CNB of QPT, increasing age and size on multivariate logistic regression. All patients diagnosed with PT following CNB of FA had enlarging lesions with a mean size of 38.3 mm.

CONCLUSIONS

Our data does not support routine excision of FELs based on size alone. All patients with QPT on CNB, regardless of size should consider excision due to high risk of PT and recurrence, and the decision to excise FAs to rule out PT should also consider whether the lesion is enlarging.

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.

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.

Preoperative interventional artery embolization for the treatment of a giant malignant phyllodes tumor: A case report

Phyllodes tumors (PTs) are rare but complex fibroepithelial lesions of the breast. The present report describes an unusual case of a giant malignant PT with a rich blood supply treated with dominant blood supply internal thoracic artery interventional embolization before surgery. A 41-year-old woman without underlying systemic disease presented with a tumor >20 cm in diameter growing rapidly in the left breast. Radiological results indicated a giant circular tumor with a clear boundary occupying the whole breast, possible invasion of the major pectoralis muscle and several enlarged lymph nodes in the left axillary region. Computed tomography angiography showed a large mass with a rich and powerful blood vessel supply and preoperative interventional embolization was performed to block the internal thoracic artery. Three days after artery embolization, mastectomy and grade I axillary lymph node dissection were performed. The giant tumor measured 17x16x11 cm. The surgery successfully treated the pain and tumor necrosis and the patient received chemotherapy and local radiotherapy. No recurrence was found at the 14-month follow-up.

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.

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.

Giant benign phyllodes breast tumour with pulmonary nodule mimicking malignancy: A case report

BACKGROUND

Phyllodes tumours (PTs) are fibroepithelial breast tumours, which can be classified as benign, borderline or malignant, according to their histological characteristics. While various huge borderline or malignant PTs have been previously described, a benign PT with a pulmonary nodule mimicking malignancy has not yet been reported. In order that doctors may have a comprehensive understanding of super-giant benign PTs (≥ 20 cm), we also performed a literature review to summarize the clinical features, differential diagnosis, and treatment of this disease.

CASE SUMMARY

A 42-year-old woman with severe anaemia presented with a rapidly enlarging right breast mass, measuring approximately 30 cm × 25 cm × 20 cm that was first noticed 1 year previously. A region of skin ulceration and necrosis (20 cm × 15 cm) was observed on the lateral side of the mass. Computed tomography (CT) of the chest revealed a pulmonary nodule, which initially suggested a diagnosis of metastasis. CT showed that the boundaries between the pectoralis major and the mass were blurred, which was presumed to be due to tumour invasion. However, two core needle biopsies of the mass showed no evidence of malignancy. Following these results, the tumour was removed by mastectomy of the right breast. Interestingly, postoperative pathology finally proved the diagnosis of a benign PT. After 1 year of follow-up, wedge resection of the small pulmonary nodule was performed, and it was confirmed that the lung nodule was actually adenocarcinoma rather than metastatic breast cancer. The patient recovered very well without any postoperative treatment.

CONCLUSION

This case is unique in that the giant breast mass initially mimicking a malignant clinical presentation was eventually pathologically confirmed to be a benign PT, which misled the diagnosis and complemented the atypical features of benign PTs. The pathological and immunohistochemical results were important in the differential diagnosis. In addition, total mastectomy should be recommended due to difficulty in the precise diagnosis of PTs, especially in large breast masses. In the literature, almost one-half of super-giant benign cases were thought to be malignant tumours before surgery. This finding is a reminder to consider all conditions in order to make an accurate diagnosis and avoid excessive treatment.

Heterogeneous risk profiles among B3 breast lesions of uncertain malignant potential

Background:

Most cases of breast lesions of uncertain malignant potential (B3) undergo surgical intervention. We aimed to analyze the outcome of B3 lesion subtypes in a large series of screen-detected cases.

Methods:

We screened 2,986 core needle biopsies to classify B3 lesions. Positive predictive values (PPVs) for malignancy were calculated for a comprehensive risk characterization according to clinicopathologic and morphologic variables.

Results:

B3 lesions comprised 35% atypical ductal hyperplasia (PPV = 20%), 16.7% flat epithelial atypia (PPV = 12%), 22.7% lobular neoplasia (PPV = 16.2%), 9% papillary lesion (PPV = 18.5%), 8.6% phyllodes tumor (PPV = 3.8%), and 8% radial scars (PPV = 4.1%) based on histopathologic diagnosis. Upgrade rates were 15.9% for calcifications, 13.7% for mass lesions, and 16.7% for architectural deformities, with 8.3% of malignant lesions classified as ductal carcinoma in situ and 6.7% as invasive cancers (PPV = 15%).

Conclusion:

B3 lesions entail a heterogeneous risk of malignancy, and careful radiologic–pathologic correlation is required for optimal treatment.

Transcatheter arterial chemoembolization improves the resectability of malignant breast phyllodes tumor with angiosarcoma component: a case report

Background

A giant phyllodes tumor of the breast is a rare fibroepithelial lesion, and its treatment is controversial. Many case reports have reported performing skin graft reconstruction after tumor excision. Chest wall resection may be required if the tumor has invaded the chest muscle layer. We speculated that transcatheter arterial chemoembolization (TACE) can improve the resectability of malignant phyllodes tumor of the breast without requiring skin grafting. The English literature contains only one case report similar to our experience.

Case presentation

We report a rare case of a 51-year-old woman who had a giant malignant phyllodes tumor with heterologous sarcomatous differentiation in her right breast. The tumor was 19.43 × 12.98 × 21.47 cm. Whole-body computed tomography (CT) and bone scan did not reveal distant metastasis. Chest magnetic resonance imaging showed chest wall tumor invasion. Considering that skin defects after mastectomy can be extensive, we administered four courses of chemoembolization in the 5 weeks before surgery (30 mg of epirubicin and embozene microspheres [400, 500, and 700 μm]/week). Each process was well tolerated, with no serious complications. Only fever and local pain at the tumor site were noted, and these symptoms resolved with time. The follow-up CT scan showed a 45% reduction in tumor volume. Therefore, simple mastectomy was performed without skin grafting reconstruction. Wound healing was satisfactory, and the patient was discharged 1 week after surgery. Pathological and immunohistochemistry (IHC) findings showed a malignant phyllodes tumor with an angiosarcoma component. Because of tumor invasion of the chest wall, we recommended the patient receive radiotherapy, but she refused. Two months after surgery, recurrence of the malignant phyllodes tumor with right axillary lymph node involvement and lung metastasis was confirmed.

Conclusion

Initial surgical resection of giant phyllodes tumors is often challenging. For initial presentation with unresectable giant phyllodes tumor, we recommend to perform TACE prior to surgery. In our patient, preoperative TACE was effective and safe. If the tumor has invaded the chest wall, early radiotherapy after surgery may be recommended for preventing recurrence.

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.

Huge borderline phyllodes breast tumor with repeated recurrences and progression toward more malignant phenotype: a case report and literature review

Background

Phyllodes tumor (PT) is a rare breast fibroepithelial biphasic tumor composed of stromal and epithelial components. The patients suffering from this disease present with a large, round, mobile, fast-growing lump, and the giant PT of more than 10 cm in diameter is so uncommon. Surgery is regarded as the primary treatment, but curative efficiency of adjuvant chemotherapy and radiotherapy is so indefinite.

Case presentation

We reported one case of a middle-aged woman with a huge borderline PT in the right breast, over 20 cm in size. The pathology of needle core biopsy of the lump was suggestive of PT of the borderline subgroup, and then she underwent mastectomy of the right breast. The patient had recovered well without any postoperative treatment until a local recurrence occurred 1 year after operation. The tumor was removed with lumpectomy, which was pathologically diagnosed as malignant PT. We followed up her by telephone and heard about her postoperative adjuvant radiotherapy and chemotherapy, as well as her well recovery.

Conclusion

The pathology of PT with low incidence is mostly benign, but local recurrence is common, and the histopathology progresses toward worsen trend. Besides, due to the difficulty in precise diagnosis of the borderline PTs, it is recommended that this subtype of patients should undergo total mastectomy. Although the curative effect of postoperative treatment has not been recognized internationally, patients, especially those with huge tumors, may benefit from these treatments.

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.

Phyllodes tumor masquerading as a fungating breast mass

Phyllodes tumor of the breast is an uncommonly encountered disease. The tumor presenting as fungating breast mass or ‘ruptured’ breast is an even more rare presentation of an unusual disease. This report documents the case of a 60-year-old female with delayed presentation of a large exophytic mass of the left breast. Biopsy of this lesion was non-diagnostic, so excision via left total mastectomy was performed. The final pathology was consistent with malignant phyllodes tumor. This report highlights the features of a rare breast cancer, the challenges in obtaining a definitive diagnosis, and the treatment of this disease, in an effort to provide clinicians with an example of the management of such a peculiar entity.

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.

Resection and reconstruction following recurrent malignant phyllodes-Case report and review of literature

INTRODUCTION

Phyllodes tumors are uncommon biphasic fibroepithelial neoplasms of the breast of varying malignant potential occurring in middle aged women. They exhibit diverse biological behavior. Margin free excision is the mainstay of treatment.

CASE PRESENTATION

A 27 year-old lady was referred with a painless ulceroproliferative right breast lesion which had rapidly progressed over six months. Three years back, she had been diagnosed with a borderline phyllodes tumor and underwent a wide local excision followed by a right mastectomy for recurrence. The resection margins were positive hence she underwent postoperative radiation. We performed a radical resection of the chest wall and reconstruction using a composite mesh (inner PTFE and outer vypro), pedicled latissimus dorsi flap and a split skin graft for the recurrent malignant tumor. She recovered uneventfully thereafter.

DISCUSSION

Malignant phyllodes tumor is uncommon and treatment principles are from case reports and retrospective studies. Aggressive resection of the lesion and reconstruction of the chest wall with bone cement and two meshes-a composite mesh (inner layer -polytetrafluroethylene and outer layer of polypropylene) and a Vypro mesh is a possibility. This case highlights the challenges encountered in managing these patients and presents a radical solution.

CONCLUSION

Treatment of phyllodes tumor necessitates adequate excision of the tumor and adjacent tissues to ensure tumor free margins. Pathological evolution from intermediate to malignant histology may be exhibited. A full-thickness chest wall resection and reconstruction although radical is a feasible option as these tumors rarely respond to other modalities of cancer management.

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.

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.

Large Malignant Phyllodes Tumor of the Breast with Metastases to the Lungs

Phyllodes tumors of the breast account for less than 0.5% of breast cancers and present most commonly in women 45 to 49 years old. The importance in managing fibroepithelial lesions lies in distinguishing fibroadenomas, which are benign, from phyllodes tumors, which can be malignant and require complete surgical excision. We report the case of a 56-year-old female who presented with a rapidly enlarging mass in her right breast 18 cm in maximum dimension that completely effaced the breast and distorted the nipple. The patient underwent a successful total mastectomy after core biopsy revealed a diagnosis of phyllodes tumor. Surgical resection is the primary treatment modality; neoadjuvant and adjuvant therapies remain controversial. Here, we report the case of a large malignant phyllodes tumor metastatic to the lungs, review the literature, and discuss diagnostic modalities and adjunct nonsurgical therapies.

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.

Phyllodes tumour among participants in screening mammography

BACKGROUND

In screening, the distinction between phyllodes tumour (PT) and fibroadenoma (FA) is imprecise, often needing surgery.

METHODS

In this retrospective cohort study and literature review, we wished to (i) present our experience with PT diagnosed among screening participants; (ii) identify discriminating features between FA and PT; (iii) assess the efficacy of cancer screening in identifying PT; and (iv) for women diagnosed with PT, determine appropriate breast cancer screening schedules.

RESULTS

During a 23.7 years time frame, PT was diagnosed in 30 women, reflecting an incidence of 2.53 per 100 000 women screened. Only 22 (73.3%) PT were found by screening. The remaining eight (26.7%) presented as interval tumours. Thirteen PT were benign, eight borderline and nine malignant. Six of eight (75%) malignant PT were symptomatic. A circumscribed mass, mean diameter 34.7 mm, was the dominant finding. Enlargement (14 imaging, seven clinical) was documented in 21 (70%) cases. Diagnostic open biopsy was required in 67.9%. Follow-up of at least 12 months is available in 20 cases. Only two developed recurrence. One woman died of metastatic PT and one PT recurred locally.

CONCLUSION

The extreme rarity of PT in screening contrasts with the prevalence of FAs. The peak incidence of PT in women is 40-50, whereas screening is targeted at women 50-74. Two yearly screening mammography is not designed to detect PT reliably. In particular, malignant PT grows rapidly and becomes symptomatic. Women with benign PT can continue with screening. Women with borderline and malignant PT should resume screening after 5 years of specialist surveillance.

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.

Breast-conserving surgery is contraindicated for recurrent giant multifocal phyllodes tumours of breast

Background

The controversy between breast conserving surgery and simple mastectomy for phyllodes tumours of the breast remains because of the unpredictable nature of the disease. Although some benign tumours may show an unusually aggressive behaviour, modified radical surgery for phyllodes tumours offers no survival advantage, and recently more conservative surgical approaches have been deployed.

Case presentation

A 30-year-old woman with a giant multifocal tumour of the breast underwent breast-conserving surgery that made use of the well- circumscribed feature of the tumour. The case demonstrates the safety, and cosmetic benefit of the breast-conserving approach for multifocal phyllodes tumours except for the high recurrence rate.

Conclusions

Large size, multifocality, and borderline or malignant histology are contraindications for breast-conserving surgery.

Visualizing typical features of breast fibroadenomas using phase-contrast CT: an ex-vivo study

Background

Fibroadenoma is the most common benign solid breast lesion type and a very common cause for histologic assessment. To justify a conservative therapy, a highly specific discrimination between fibroadenomas and other breast lesions is crucial. Phase-contrast imaging offers improved soft-tissue contrast and differentiability of fine structures combined with the potential of 3-dimensional imaging. In this study we assessed the potential of grating-based phase-contrast CT imaging for visualizing diagnostically relevant features of fibroadenomas.

Materials and Methods

Grating-based phase-contrast CT was performed on six ex-vivo formalin-fixed breast specimens containing a fibroadenoma and three samples containing benign changes that resemble fibroadenomas using Talbot Lau interferometry and a polychromatic X-ray source. Phase-contrast and simultaneously acquired absorption-based 3D-datasets were manually matched with corresponding histological slices. The visibility of diagnostically valuable features was assessed in comparison with histology as the gold-standard.

Results

In all cases, matching of grating-based phase-contrast CT images and histology was successfully completed. Grating-based phase-contrast CT showed greatly improved differentiation of fine structures and provided accurate depiction of strands of fibrous tissue within the fibroadenomas as well as of the diagnostically valuable dilated, branched ductuli of the fibroadenomas. A clear demarcation of tumor boundaries in all cases was provided by phase- but not absorption-contrast CT.

Conclusions

Pending successful translation of the technology to a clinical setting and considerable reduction of the required dose, the data presented here suggest that grating-based phase-contrast CT may be used as a supplementary non-invasive diagnostic tool in breast diagnostics. Phase-contrast CT may thus contribute to the reduction of false positive findings and reduce the recall and core biopsy rate in population-based screening. Phase-contrast CT may further be used to assist during histopathological workup, offering a 3D view of the tumor and helping to identify diagnostically valuable tissue sections within large tumors.

Immediate implant breast reconstruction with acellular dermal matrix for treatment of a large recurrent malignant phyllodes tumor

Phyllodes tumors (PT) are rare fibroepithelial breast tumors representing less than 1 % of all breast malignancies. These tumors are unpredictable and fast growing with a high local recurrence rate, making this disease challenging to treat. Previous literature focused on surgical resection, and breast reconstruction following a mastectomy in patients with PT is rarely addressed. We report a case of a recurrent malignant PT treated with a nipple-sparing mastectomy followed by immediate single-stage silicone implant breast reconstruction. While PT is a rare breast malignancy that presents challenges with both surgical resection and reconstruction, we demonstrate that nipple-sparing mastectomy with immediate implant breast reconstruction with AlloMax is curative and can offer an appealing cosmetic option.

LEVEL OF EVIDENCE V

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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.

Malignant phyllodes tumors of the breast: a study in clinical practice

Malignant phyllodes tumors are an uncommon breast tumor in clinical practice of surgery. The study population consisted of five consecutive patients. Each patient had complete clinical follow-up with annual mammograms and physical examination in a specialized breast clinic. They were surgically treated for with malignant phyllodes tumor of the breast. All patients are alive and well with a complete follow-up. The first 2 patients had a fine needle aspiration cytology and were surgically treated by a simple mastectomy. The remaining 3 patients were preoperatively diagnosed with core needle biopsy. These 3 patients were treated with a wide excision of the phyllodes tumor with at least a 1-cm margin of normal breast tissue. Mammography was 100% accurate in demonstrating a dense breast mass. In each patient ultrasound suggested heterogeneous internal echoes present in each malignant phyllodes tumor. Fine needle aspiration cytology was of no value in the diagnosis of a phyllodes tumor. Core needle biopsy is highly reliable in establishing a preoperative diagnosis. The most helpful clinical observation of a malignant phyllodes tumor was rapid growth and enlargement, which is frequently noted by the patient.

Rapidly progressive multifocal phyllodes tumour of the breast: A case report and review of the literature

INTRODUCTION

Malignant transformation of a phyllodes tumour is a rare form of breast cancer, accounting for just 0.5% of all breast cancer cases.(1) PRESENTATION OF CASE: We report a case of a 49 year old female with rapidly progressive, multifocal disease. She initially presented with two giant fibroadenomas which were excised. She represented eight months post surgery with two new lesions in the same breast, one suspicious, one suggestive of fibroadenoma. Biopsy was borderline. Surgery was therefore scheduled for wide local excision. At localisation two weeks later, at least eight lesions were seen on ultrasound scan. Three were removed as histology was at this point unknown to conserve the breast. Histology revealed intermediate grade DCIS, benign Phyllodes and borderline/malignant phyllodes. She was scheduled for mastectomy and immediate Strattice reconstruction. An MRI was performed pre-operatively to ascertain extent of disease. Two weeks post localisation, 13 lesions were identified. The right breast was entirely unaffected. Surgery interval was three weeks and final histology revealed 18 lesions, ranging from fibroadenoma through to borderline/malignant phyllodes with an incidental papilloma.

DISCUSSION

This is the first report of such rapid progression of disease, with 16 new lesions, of varied histology, developing in just an eight week period.

CONCLUSION

This case highlights the difficulty of forming a clear diagnostic and therapeutic pathway in this highly variable disease. Arguments for over and under treating these patients remain but those with any borderline/malignant potential have to be removed as recurrence is both common and aggressive, with a clear surgical margin the only proven protective factor.

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.

Clinical and radiologic data and core needle biopsy findings should dictate management of cellular fibroepithelial tumors of the breast

Fibroepithelial lesions with cellular stroma identified on core needle biopsy (CNB) may prove to be either fibroadenoma or phyllodes tumor at excision; therefore, management of these rare lesions is highly controversial. We aim to assess the management and the outcome of 101 cellular fibroepithelial lesions diagnosed on CNB over a 6-year period in one institution. Consensus on clinical management in each individual patient was reached during multi-disciplinary conferences, based on careful correlation of clinical data with results of imaging studies and pathology of CNB samples. Radiologic findings (mammogram and sonogram) and multiple histologic parameters on CNB specimen were blindly re-evaluated by one experienced breast radiologist and two breast pathologists, respectively, and results were correlated with final diagnosis at excision. Cellular fibroepithelial lesions with indeterminate or suspect imaging findings, with larger size, and with an equivocal comment such as "cannot rule out phyllodes tumor" in the pathology report were excised more frequently (p = 0.05, p = 0.034, and p = 0.01, respectively). Of 43 excised lesions, 13 were classified as benign phyllodes tumors, 23 as fibroadenoma and seven as benign cellular fibroepithelial lesion. The final diagnosis at excision did not significantly correlate with any clinical data, or with retrospective evaluation of imaging findings or comprehensive evaluation of multiple histologic parameters. In 58 patients who had clinical and radiologic follow-up (mean ± SD: 30 ± 21 months) there was no evidence of disease progression. No clinical and radiologic findings and/or comprehensive evaluation of multiple histologic parameters on CNB specimen are distinctive enough to predict final classification of equivocal cellular fibroepithelial lesions. However, careful clinico-pathologic and radiologic correlation may help to select the most clinically significant lesions for proper immediate surgical management. Follow-up alone may be an appropriate alternative for a subset of patients, given a good clinical, pathologic, and radiologic correlation.

Imaging findings in phyllodes tumors of the breast

PURPOSE

To study the radiological appearance and pathological features of breast phyllodes tumors (PTs), and to enhance the recognition of the tumor.

MATERIALS AND METHODS

Clinical and imaging findings were retrospectively reviewed in 24 women with PTs confirmed by surgical pathology. All of the 24 patients had preoperative MRI and sonography, and 10 had preoperative mammography.

RESULTS

The histologic findings were benign, borderline and malignant PTs in 16.7% (4/24), 45.8% (11/24) and 37.5% (9/24) of cases, respectively. The tumor size (p=0.001), irregular shape on sonographic imaging (p=0.039), internal non-enhanced septations (p=0.009), silt-like changes in enhanced images (p=0.006) and signal changes from T2-weighted to enhanced images on MRI (p=0.001) correlated significantly with the histologic grade; the BI-RADS category of the MRI could reflect the PT's histologic grade with a correlation coefficient of 0.440 (p=0.031). If the category BI-RADS ≥4a was considered to be a suspicious malignant lesion, the diagnostic accuracy of mammography, US and MRI would be 70% (7/10), 62.5% (15/24) and 95.8% (23/24), respectively.

CONCLUSION

The tumor size and several US and MRI findings can be used to help preoperatively determine the histologic grade of breast PTs. When a patient presents with a progressively enlarging, painless breast mass, MRI should be recommended first.

Recurrent challenges in the evaluation of fibroepithelial lesions

CONTEXT

The morphologic spectrum of mammary fibroepithelial lesions ranges from fibroadenoma, a common benign neoplasm, to phyllodes tumor, an uncommon lesion that can sometimes recur and metastasize.

OBJECTIVE

To focus on problems encountered in the diagnostic evaluation of fibroepithelial tumors, highlighting the diagnostically relevant morphologic features and providing an update on the immunohistochemical profile and genetic alterations of these rare neoplasms.

DATA SOURCES

A PubMed search of the English-language literature identified published reports on fibroepithelial lesions, with a special focus on phyllodes tumor. The results and conclusions of these studies form the basis of this review.

CONCLUSIONS

The distinction between fibroadenoma and phyllodes tumor is usually not problematic, especially in excision specimens. In some cases, however, the diagnostic evaluation of fibroepithelial lesions can be challenging, especially if only limited material is available. Morphologic predictors of local recurrence of phyllodes tumor include cellularity and cytologic atypia, mitotic activity, positive margins, infiltrative borders, fibroproliferative satellite nodules, and past history of fibroadenoma. Predictors of distant metastasis include size, tumor necrosis, and stromal overgrowth. None of these parameters, however, constitutes a definite marker of malignancy. Presently, molecular and immunohistochemical techniques play a limited role in the diagnosis of fibroepithelial lesions.

False-negative diagnoses at stereotactic vacuum-assisted needle breast biopsy: long-term follow-up of 1,280 lesions and review of the literature

OBJECTIVE

The purpose of this study was to determine retrospectively the frequency and causes of false-negative diagnoses of lesions evaluated with percutaneous stereotactic biopsy performed with vacuum-assisted probes with the patient prone on a biopsy table.

MATERIALS AND METHODS

The records of 1,152 women (median age, 55 years; range, 31-94 years) with 1,280 lesions consecutively biopsied with 14-gauge (n = 159) or 11-gauge (n = 1,121) vacuum probes were reviewed retrospectively. The histologic diagnoses were malignant (n = 489), high-risk (n = 117), and benign (n = 674) lesions. Benign lesions were evaluated with repeated biopsy (n = 46) or mammographic follow-up for 24 months or longer (n = 506) or less than 24 months (n = 57). In 65 cases (10% of all benign lesions), follow-up was not performed. Fisher's exact tests were used to correlate patient, mammographic, and biopsy variables with false-negative diagnoses.

RESULTS

Of 508 lesions with a final diagnosis of malignancy, the initial needle biopsy diagnosis was malignant (n = 489), high-risk (n = 14), or benign (n = 5) lesion. The five false-negative diagnoses were related to gauge of the biopsy probe and specimen radiographic findings regarding calcifications but were not related to lesion type. False-negative diagnoses were made in 4.4% (three of 68) of cases in which 14-gauge vacuum biopsy was performed and in 0.45% (two of 440) of cases in which 11-gauge vacuum biopsy was performed (p = 0.019). False-negative diagnoses were made in 25% (one of four) of cases in which specimen radiographs showed no calcifications and 0.67% (two of 300) of cases in which they did show calcifications (p = 0.0390). False-negative diagnoses were made in 1.2% (three of 248) of cases of calcification lesions and 0.8% (two of 260) of cases of mass lesions (p = 0.679).

CONCLUSION

False-negative findings at stereotactic biopsy were least common with 11-gauge probes and were similar in frequency for calcifications and masses.

Recent developments in the histological diagnosis of spindle cell carcinoma, fibromatosis and phyllodes tumour of the breast

This article reviews recent advances in the diagnosis of these three unusual tumours of the breast. Spindle cell carcinoma needs to be considered in the differential diagnosis of many mammary spindle cell lesions: it is important to be aware of the wide range of appearances, including the recently described fibromatosis-like variant. Immunohistochemistry using a broad panel of cytokeratin antibodies is needed to exclude spindle cell carcinoma; there is frequent expression of basal cytokeratins and p63. CD34 is often expressed by the stroma of phyllodes tumours, but does not appear to be expressed by spindle cell carcinoma or fibromatosis. Nuclear beta-catenin is found in about 80% of fibromatoses, but can also be seen in spindle cell carcinomas and phyllodes tumours. Two recent studies have described features useful in the distinction of phyllodes tumour and fibroadenoma on core biopsy, including increased cellularity, mitoses and overgrowth of the stroma, adipose tissue in the stroma and fragmentation of the biopsy specimen. Periductal stromal tumour is a recently described biphasic tumour composed of spindle cells around open tubules or ducts (but no leaf-like architecture) with frequent CD34 expression. The overlap of morphology with phyllodes tumour suggests that it may be best regarded as a variant of phyllodes tumour.