Breast desmoid tumor management in France: toward a new strategy

Active surveillance and emerging medical treatment options for desmoid: when and for whom?

PURPOSE OF REVIEW

This article discusses the evolving approaches to desmoid tumors management, shedding light on recent developments.

RECENT FINDINGS

Active surveillance has become the primary approach for managing primary peripheral desmoid tumors. This strategy was initially based on evidence from retrospective studies. Roughly 50% of cases managed with active surveillance show spontaneous stabilization or regression. Recent prospective trials conducted in Italy, The Netherlands, and France (2022-2023) confirm the efficacy of active surveillance, revealing 3-year progression-free survival rates ranging from 53.4 to 58%. For the patients under active surveillance, decisions regarding treatment are based on significant tumor growth or progressive symptoms. Moreover, three contemporary randomized trials investigated medical treatments for progressive or recurrent desmoid tumors. Sorafenib, pazopanib, and nirogacestat demonstrated clinical activity, as evidenced by favorable progression-free survival and objective response rates.

SUMMARY

Active surveillance has solidified its position as the primary management approach for desmoid tumors, validated by three robust prospective studies. Three recent randomized trials explored medical treatment for progressive or recurrent desmoid tumors, revealing promising clinical activities.

Diagnosis and Management of Desmoid Fibromatosis of the Breast

Desmoid fibromatosis of the breast (also known as desmoid tumor of the breast) is a rare entity infrequently encountered by oncologists and surgeons caring for patients with breast disease. The current body of literature is highly reliant on case series and extrapolations from other sites of desmoid tumor-related disease. Much remains unclear regarding the pathological origins, natural history, and response to treatment of this condition. Traditional treatment strategies have centered on surgical resection, which may result in significantly disfiguring cosmetic and functional outcomes, frequent need for re-operation, and associated morbidity. There are limited data to support the superiority of upfront surgical resection when compared to medical therapy or watchful waiting strategies. Current treatment guidelines for desmoid tumors do not focus on the breast as a site of disease and are purposefully ambiguous due to the paucity of evidence available. We aim to review the literature concerning desmoid fibromatosis of the breast and propose an algorithm for current evidence-based management of this rare disease in the context of our experience with this pathology at a high-volume quaternary referral center.

Breast Sarcomas, Phyllodes Tumors, and Desmoid Tumors: Turning the Magnifying Glass on Rare and Aggressive Entities

Breast sarcomas (BSs), phyllodes tumors (PTs), and desmoid tumors (DTs) are rare entities that arise from connective tissue. BSs can be classified as either primary or secondary, whether they develop de novo or after radiation exposure or lymphedema. PIK3CA seems to play an important common role in different BS. Malignant PTs show similar behavior to BSs, while DTs are locally aggressive but rarely metastasize. BSs usually present as unilateral, painless, rapidly growing masses with rare nodal involvement. The diagnosis should be based on magnetic resonance imaging and a core needle biopsy. Staging should comprise a chest computed tomography (CT) scan (except for benign PT and DT), while abdominal and pelvic CT scans and bone scans should be added in certain subtypes. The mainstay of treatment for localized BS is surgery, with margin goals that vary according to subtype. Radiotherapy and chemotherapy can be used as neoadjuvant or adjuvant approaches, but their use in these settings is not standard. Advanced BS should be treated with systemic therapy, consistent with recommendations for advanced soft tissue sarcomas of other topographies. Given the rarity and heterogeneity of these entities, multidisciplinary and multi-institutional collaboration and treatment at reference centers are critical.

Fibromatosis of the breast; another diagnosis of cancer like lesions: About 4 cases reports

INTRODUCTION AND IMPORTANCE

Desmoid fibromatosis is a benign monoclonal fibroblastic tumor that was first reported in 1832 and arises from musculoaponeurotic structures. It is an uncommon tumor that can mimic breast carcinoma in both hits clinical and radiological presentation. This entity mainly affects patients in their fourth and fifth decades of life.

CASE PRESENTATION

Our four patients were of young women in their 2nd and 3rd decade that consulted for masses of the breast. These lesions were suspicious for malignancy in both their clinical and radiological features despite not having any family history of breast carcinoma.

CLINICAL DISCUSSION

Only histology provides the diagnosis, it is locally invasive, non-metastatic but with a high potential of recurrence and the sole treatment is complete and wide local excision with clear margins.

CONCLUSION

Although it is a rare clinical scenario, the presence of an unusual breast or chest wall tumor such as a desmoid tumor should be considered when obvious breast changes and history do not correlate with routine diagnostic measures.

Effect of Tranilast on the Frequency of Invasive Treatment for Extra-Abdominal Desmoid Fibromatosis

BACKGROUND

Active surveillance (AS) has been suggested for managing extra-abdominal desmoid fibromatosis (EADF), but a substantial percentage of such patients transitioned to invasive secondary treatments. The anti-keloid medication tranilast is frequently used in Japan but its effectiveness for EADF is not well understood.

METHODS

We retrospectively analyzed the medical records of EADF patients treated with tranilast between January 2009 and March 2021. EADF has been reported to shrink spontaneously, so the effects of all drugs must be compared with AS. To assess the effect of tranilast, we compared the clinical courses of patients receiving tranilast with those managed by AS (as identified in a systematic review). A systematic review of AS outcomes was conducted on July 22, 2021, in accordance with PRISMA guidelines. The primary endpoint was rate of conversion to secondary treatment. Secondary endpoints were progression-free survival, objective response rate (ORR), disease control rate (DCR), and adverse events. The rates of conversion to secondary treatment, ORRs, and DCRs were compared between the two groups by using the Fisher exact test.

RESULTS

Eighteen patients who received tranilast as initial treatment for EADF were included. Two patients (11.1%) underwent surgical resection for treatment of tumor growth and persistent pain. The rate of conversion to secondary treatment was significantly lower for tranilast than for a pure AS approach (40.1%; p = 0.01). ORR and DCR did not differ between groups.

CONCLUSIONS

Tranilast was better than AS for initial management of EADF.

[B3 lesions of the breast: histological, clinical, and epidemiological aspects : Update]

B3 lesions of the breast are a heterogeneous group of lesions with uncertain malignant potential encompassing a broad spectrum of histologically distinct alterations that often pose challenging decisions if diagnosed on the preoperative core or vacuum biopsies. B3 lesions are mostly detected due to mammographic calcifications or mass lesions and, in most cases, encompass a spectrum of atypical lesions such as atypical ductal hyperplasia, classic lobular neoplasia, flat epithelial atypia, papillomas, fibroepithelial tumors, and rarely other lesions such as mucocele-like lesions, atypical apocrine lesions, and rare stromal proliferations. The use of immunohistochemical stains (estrogen receptors, basal cytokeratin, myoepithelial markers, and stromal marker panel) is useful in the differentiation of these lesions and allowing proper classification. Regarding clinical management of B3 lesions, the radiological-pathological correlation of the given entity plays the most important key element for the proper next diagnostic and therapeutic step.

Pitfalls in breast pathology

Accurate pathological diagnosis is the cornerstone of optimal clinical management for patients with breast disease. As non-operative diagnosis has now become the standard of care, histopathologists encounter the daily challenge of making definitive diagnoses on limited breast core needle biopsy (CNB) material. CNB samples are carefully evaluated using microscopic examination of haematoxylin and eosin (H&E)-stained slides and supportive immunohistochemistry (IHC), providing the necessary information to inform the next steps in the patient care pathway. Some entities may be difficult to distinguish on small tissue samples, and if there is uncertainty a diagnostic excision biopsy should be recommended. This review discusses (1) benign breast lesions that may mimic malignancy, (2) malignant conditions that may be misinterpreted as benign, (3) malignant conditions that may be incorrectly diagnosed as primary breast carcinoma, and (4) some IHC pitfalls. The aim of the review is to raise awareness of potential pitfalls in the interpretation of breast lesions that may lead to underdiagnosis, overdiagnosis, or incorrect classification of malignancy with potential adverse outcomes for individual patients.

Desmoid fibroma simulating malignant breast neoplasm: A case report and literature review

INTRODUCTION

Desmoid fibroma (DF) is a disorder characterized by strong clonal proliferation of myofibroblasts and fibroblasts. We describe a case of DF that mimicked a breast tumor, along with a review of the literature on the clinical manifestation, diagnostic process, and course of therapy for this combative disease.

CASE REPORT

A 34-year-old female patient with breast lump at the junction of the upper quadrants of the left breast. After the diagnosis of DF, it was decided to perform a sectorectomy of the left breast associated with post-quadrant reconstruction, with immunohistochemistry and findings compatible with DF.

DISCUSSION

Clinically manifests as a solid mass that is often painless and occasionally adherent to the chest wall. A treatment strategy should be idealized for each patient. Thus, there is the possibility of performing radical surgery for resection and/or radiotherapy, and surgery may be followed by radiotherapy.

Bilateral breast desmoid-type fibromatosis, case report and literature review

BACKGROUND

Breast desmoid-type fibromatosis (BDF) is a rare mesenchymal tumor accounting for only 0.2% of solid breast tumors. It is classified as an intermediate tumor because it is locally aggressive but has no metastatic potential. Its diagnosis is often difficult because it shares many clinical and radiologic aspects with breast carcinomas and therefore relies on anatomopathological analysis which may be supplemented by genetic analysis. The treatment of BDF has considerably evolved in the past years. While surgery was the cornerstone of the management prior to the 2000s, recent data have shown the value of active surveillance (AS) from the time of diagnosis. Indeed, after 2 years of AS, the progression-free survival (PFS) of the disease is identical or superior to surgery. Moreover, spontaneous regression has been observed in 30% of patients undergoing AS. In case of disease progression, surgery can be considered on a case-by-case basis, as well as systemic treatments.

CASE DESCRIPTION

We present a case of bilateral BDF affecting a 20-year-old woman for whom the first suggested treatment was bilateral mastectomy with reconstruction. After a second opinion, the decision was revised and AS was initiated. Almost 3 years after the onset of AS, tumors have shown a continuous regression.

CONCLUSIONS

This case demonstrates the need for experience in the management of mesenchymal tumors to avoid overtreatment by mutilating surgeries which promote recurrence. Moreover, to our knowledge, very few cases of bilateral BDF have been published to date. It thus seemed relevant for us to report this rare case which supports the interest of AS for DF, as recently advised by the Desmoid Tumor Working Group guidelines.

Low to Intermediate (Borderline) Grade Breast Spindle Cell Lesions on Needle Biopsy: Diagnostic Approach and Clinical Management

Spindle cell proliferations of the breast are a heterogeneous group of lesions ranging from benign or reactive lesions to aggressive malignant neoplasms. Diagnosis on core biopsy can be particularly challenging as lesions displaying different lineages associated with variable outcomes share overlapping morphologies (scar vs. fibromatosis-like metaplastic carcinoma) whereas individual entities can exhibit a large variety of appearances (myofibroblastoma). In this review, lesions are grouped into lineage, when possible, including those showing fibroblastic/myofibroblastic differentiation, ranging from entities that require no additional management, such as scar and nodular fasciitis, to those with unpredictable clinical outcomes such as fibromatosis and solitary fibrous tumor or locally aggressive behavior such as dermatofibrosarcoma protuberans. The review of low-grade vascular lesions includes atypical vascular lesion and low-grade angiosarcoma. Also discussed are various adipocytic lesions ranging from lipoma to liposarcoma, and rare smooth muscle and neural entities more commonly encountered in locations outside the breast, such as leiomyoma, neurofibroma, schwannoma, or granular cell tumor. Optimal histological evaluation of these entities merges clinical and radiologic data with morphology and ancillary testing. We present our approach to immunohistochemical and other ancillary testing and highlight issues in pathology correlation with imaging. Recent updates in the management of breast spindle cell lesions are addressed. In a well-sampled lesion with radiographic concordance, the core biopsy diagnosis reliably guides management and we advocate the inclusion of management recommendations in the pathology report. Precise characterization using up to date guidelines is important to identify a subset of patients who may safely avoid unnecessary surgical procedures. A multidisciplinary approach with close collaboration with our clinical colleagues is emphasized.

Desmoid tumors: who, when and how to treat?

PURPOSE OF REVIEW

The objective of this article is to summarize new treatment strategies of desmoid tumors.

RECENT FINDINGS

Desmoid tumor has an unpredictable evolution that may spontaneously regress or stabilize. A shift toward an initial frontline active surveillance has been acknowledged by experts. Surveillance monitoring should be performed frequently after the diagnosis to avoid missing a significant progression and then spaced in case of stabilization. Treatment is based on significant tumor growth or symptoms. Recent guidelines recommend commencing medical treatment. Kinase inhibitors and cytotoxic agents are the two classes of drugs where studies included progressive desmoid tumors and should be selected to guide medical practice. In a randomized trial, 2 years progression-free survival (PFS) was significantly better in the sorafenib group (81 versus 36% in the placebo group). In another randomized phase 2, 6 months PFS was 83.7% with pazopanib versus 45% with methotrexate and vinblastine. In a retrospective study, including progressive desmoid tumors, methotrexate + vinca alkaloids achieved 75 months median PFS. Cryotherapy is an alternative option in desmoid tumors with compatible locations and tumor sizes. Following medical treatment or cryotherapy failure, superficial sites represent the best indications for surgery in cases of continuous progression. In the event of a contra-indication or failure of medical treatment, in locations where surgery would be mutilating and incomplete, radiotherapy is an effective option.

SUMMARY

Active surveillance with planned imaging has become the first-line management in desmoid tumor.

Desmoid tumors located in the abdomen or associated with adenomatous polyposis: French intergroup clinical practice guidelines for diagnosis, treatment, and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFR)

INTRODUCTION

Desmoid tumor (DT) of the abdomen is a challenging and rare disease. The level of evidence available to document their treatment is relatively low, however, recent publications of prospective studies have allowed to precise their management.

METHODS

This document is a summary of the French intergroup guidelines realized by all French medical and surgical societies involved in the management of DT located in the abdomen or associated with adenomatous polyposis. Recommendations are graded in four categories (A, B, C and D), according to the level of evidence found in the literature until January 2021.

RESULTS

When the diagnosis of DT is suspected a percutaneous biopsy should be performed when possible. A molecular analysis looking for pathogenic mutations of the CTNNB1 and APC genes should be systematically performed. When a somatic pathogenic variant of the APC gene is present, an intestinal polyposis should be searched. Due to a high rate of spontaneous regression, non-complicated DT should first benefit from an active surveillance with MRI within 2 months after diagnosis to assess the dynamic of tumor growth. The treatment decision must be discussed in an expert center, favoring the less toxic treatments which can include broad spectrum tyrosine kinase inhibitor or conventional chemotherapy (methotrexate-vinblastine). Surgery, outside the context of emergency, should only be considered for favorable location in an expert center.

CONCLUSION

French guidelines for DT management were elaborated to help offering the best personalized therapeutic strategy in daily clinical practice as the DT therapeutic landscape is complexifying. Each individual case must be discussed within a multidisciplinary expert team.

Breast Fibromatosis: Radiologic-Pathologic Correlation

Fibromatosis of the breast is a rare, benign locally infiltrative tumor without metastatic potential. Patients typically present with a painless, palpable, firm breast mass, which may be mobile or fixed to the pectoralis muscle. While some cases are related to familial mutations in the adenomatous polyposis coli (APC) gene, the majority are sporadic due to somatic mutations or prior injury to the breast tissue. On mammography, fibromatosis is typically seen as an irregular, dense, spiculated mass. US demonstrates a hypoechoic, irregular mass with indistinct margins. Fibromatosis is indistinguishable from breast cancer on imaging, and core biopsy is required for definitive diagnosis. Wide local excision is the historical standard for treatment; however, recurrence rates are high, and other emerging therapies are being explored. This article reviews the clinical features, imaging and histopathologic findings, along with brief overview of management.

A nonrandom association of breast implants and the formation of desmoid tumors

BACKGROUND

Studies suggest that surgical breast augmentation with implants is a risk factor for breast desmoid tumors. The statistical strength of this correlation is unknown, as evidence is limited to anecdotal reports.

METHODS

Patients with breast desmoid tumors and a history of breast implants seen at a single center between 2000 and 2021 were identified via radiology, breast, and sarcoma databases. The standardized incidence ratio (SIR) was calculated to assess the correlation between breast desmoid tumors and breast implants. The cases were pooled with published cases for analyses. Progression-free survival curves and hazard ratios were estimated using the Kaplan-Meier method and Cox proportional-hazards modeling.

RESULTS

Fourteen patients from one institution and 66 cases in the literature were identified. All patients were female, and the mean age was 38 years old (range 20-66). 63 patients (82%) underwent resection, 9 (12%) received chemotherapy, 3 (4%) received sorafenib, 11 (14%) received hormonal therapy, and 3 (4%) underwent active surveillance. After resection, the 2-year recurrence-free survival rate was 77% (95% CI 65%-89%). The recurrence risk was lower for resection with no residual tumor (R0) compared to microscopic (R1) or macroscopic (R2) residual tumor (HR: 0.15; 95% CI 0.02-0.8; p < 0.05). The SIR was 482 (95% CI 259-775) to 823 (95% CI 442-1322), suggesting a 482-823 times higher risk of developing a breast desmoid tumor after breast augmentation than the general population.

CONCLUSION

We present a nonrandom association between breast implants and desmoid tumors. Whether the tumors arise from the surgical trauma or the implant's biomaterial is unknown. When surgery is indicated, negative margins reduce the risk of recurrence.

Spindle cell lesions of the breast: a diagnostic approach

Spindle cell lesions of the breast comprise a heterogeneous group of lesions, ranging from reactive and benign processes to aggressive malignant tumours. Despite their rarity, they attract the attention of breast pathologists due to their overlapping morphological features and diagnostic challenges, particularly on core needle biopsy (CNB) specimens. Pathologists should recognise the wide range of differential diagnoses and be familiar with the diverse morphological appearances of these lesions to make an accurate diagnosis and to suggest proper management of the patients. Clinical history, immunohistochemistry, and molecular assays are helpful in making a correct diagnosis in morphologically challenging cases. In this review, we present our approach for the diagnosis of breast spindle cell lesions, highlighting the main features of each entity and the potential pitfalls, particularly on CNB. Breast spindle cell lesions are generally classified into two main categories: bland-appearing and malignant-appearing lesions. Each category includes a distinct list of differential diagnoses and a panel of immunohistochemical markers. In bland-appearing lesions, it is important to distinguish fibromatosis-like spindle cell metaplastic breast carcinoma from other benign entities and to distinguish fibromatosis from scar tissue. The malignant-appearing category includes spindle cell metaplastic carcinoma, stroma rich malignant phyllodes tumour, other primary and metastatic malignant spindle cell tumours of the breast, including angiosarcoma and melanoma, and benign mimics such as florid granulation tissue and nodular fasciitis.

Mimickers of breast malignancy: imaging findings, pathologic concordance and clinical management

Many benign breast entities have a clinical and imaging presentation that can mimic breast cancer. The purpose of this review is to illustrate the wide spectrum of imaging features that can be associated with benign breast diseases with an emphasis on the suspicious imaging findings associated with these benign conditions that can mimic cancer. As radiologic-pathologic correlation can be particularly challenging in these cases, the radiologist’s familiarity with these benign entities and their imaging features is essential to ensure that a benign pathology result is accepted as concordant when appropriate and that a suitable management plan is formulated.

Ultrasound-Guided Vacuum-assisted Biopsy Versus Surgical Resection in Patients With Breast Desmoid Tumor

BACKGROUND

Recent studies suggest that desmoid tumors can be managed more conservatively rather than undergoing wide surgical resection (SR). Ultrasound-guided vacuum-assisted biopsy (UGVAB) is a minimally invasive technique. This retrospective study aimed to compare the outcome in patients with breast desmoid tumor (BDT) who received UGVAB alone versus SR.

MATERIALS AND METHODS

The pathology database was searched for patients diagnosed with BDT ≤ 3 cm from 2007 to 2019. All patients underwent breast ultrasound examination and were then performed UGVAB alone or local SR. The Kaplan-Meier method with a log-rank test was used as a univariate analysis to compare the relapse-free survival (RFS) rates between UGVAB and SR groups. Cox regression analysis was used for multivariate analysis.

RESULTS

A total of 39 patients were included. The median follow-up was 41 mo (range, 5-110 mo). The incidence of tumor recurrence was 23.1% (9/39). The 3-y cumulative RFS was 83.1% and 95.8% in the UGVAB and SR group, respectively, which was not significantly different between the two groups (P = 0.131, log-rank test). Multivariate analysis also revealed that treatment strategy (UGVAB versus SR) was not associated with an increased risk of relapse events (P = 0.274).

CONCLUSIONS

Small desmoid tumors (≤3 cm) after UGVAB alone did not have a significantly compromised RFS compared with those who underwent SR. UGVAB may be an alternative and relatively conservative method for the diagnosis and local control of BDT with a smaller size. A prospective, randomized study with large sample size is needed to confirm this observation.

Lower Rate of CTNNB1 Mutations and Higher Rate of APC Mutations in Desmoid Fibromatosis of the Breast: A Series of 134 Tumors

Desmoid fibromatosis (DF) is a rare, locally aggressive, nonmetastasizing fibroblastic/myofibroblastic tumor with a tendency to recur and an unpredictable clinical course. A "wait-and-see" policy is the new standard of care. DF are characterized by activating alterations of the wnt/β-catenin pathway: CTNNB1 or adenomatous polyposis coli gene (APC) mutations (these mutations being mutually exclusive). Desmoid-type fibromatosis of the breast (DFB) is rare with an incidence of 0.2% of breast tumors. The diagnosis of DFB is difficult, as it must be distinguished from metaplastic carcinoma and other spindle cell lesions. Sequencing of 128 DFB identified a lower rate of CTNNB1 mutations using Sanger (65.6%) or Sanger+next-generation sequencing (77.7%) and a higher rate of APC mutations (11.8%) than in all-site DF. By excluding patients with familial adenomatous polyposis (n=2), the rate of APC mutations in DFB was high (10.7%). The distribution of CTNNB1 mutations in DFB was different from all-site DF, with a higher rate of T41A (68.9%), a lower rate of S45F (5.7%), and a similar rate of S45T (12.6%). By combining the 2 molecular techniques in a 2-step manner (Sanger, then next-generation sequencing), we increased the detection rate of CTNNB1 mutations and lowered the rate of wild-type tumors from 34.4% to 9.8%, therefore improving the diagnosis of DFB. The identification of the exon 3 CTNNB1 mutation in breast spindle cell lesions is a highly specific tool for the diagnosis of DFB, in addition to extensive immunohistochemical analysis. Our study also underlines the importance of APC in DFB tumorigenesis. These findings have significant implications for patient care and management.

Desmoid-type fibromatosis of the lower extremity: A unique case of complete lesion resolution following core needle biopsy

Desmoid-type fibromatosis (DF) is a rare neoplasm characterized by fibroblastic and myofibroblastic proliferation. While characterized as a benign lesion that does not metastasize, desmoid-type fibromatosis exhibits a wide range of behavior from aggressive local tissue invasion and post-surgical recurrence to spontaneous regression. Tumor regression can occur following systemic medical therapy or rarely may occur in the absence of therapy. We present a case of a 50-year-old female with a left thigh vastus medialis intramuscular mass which underwent imaging work-up and subsequent core needle ultrasound-guided biopsy showing results of desmoid-type fibromatosis. Following biopsy, the tumor showed prompt, complete regression with complete MRI resolution 2 months following biopsy. The patient showed no evidence of disease recurrence out to one year on MRI surveillance. This case report will discuss desmoid-type fibromatosis imaging features, treatment strategies, spectrum of disease behavior, and atypical behavior such as the spontaneous tumor regression as seen in this case report. To our knowledge there have been no reported cases of DF spontaneous regression 2 months following a core needle biopsy. Understanding the variable behavior of desmoid-type fibromatosis can assist the radiologist in guiding management of these lesions with the goal of optimizing clinical outcomes and preventing unnecessary aggressive treatments for stable or regressing disease.

Fibromatosis of the breast: a 10-year multi-institutional experience and review of the literature

BACKGROUND

Breast fibromatosis is a rare clinical entity, but poses significant diagnostic and therapeutic challenges. In light of recent changes in management practices, the aim was to review our institutional experience of breast fibromatosis and provide a review of current available literature on such management.

METHODS

A search of pathological databases within two tertiary institutions for all patients diagnosed with fibromatosis of the breast over a 10-year period (2007-2016) was performed. Clinicopathological characteristics and modes of treatment were recorded for each patient. Concurrently a comprehensive literature search was performed and studies relating to breast fibromatosis and its management were identified and reviewed.

RESULTS

Sixteen patients were identified. Median age at diagnosis was 42 (range 21-70) and all patients were diagnosed with core biopsy. The most useful imaging modality in diagnosis was ultrasonography and magnetic resonance imaging. 13/16 were treated surgically whilst 3/16 were treated using a watch-and-wait approach. 6/13 (46%) required re-excision of margins and 2/13 (15%) had recurrence after surgery. On review of the literature, there is no dedicated guideline in place for the management of breast fibromatosis. Currently a 'watch and wait' approach is favoured over surgical intervention due to high levels of recurrence and associated surgical morbidity. All cases should be discussed at a sarcoma multidisciplinary team meeting and tyrosine kinase inhibitors should be considered in advanced cases.

CONCLUSIONS

Breast fibromatosis is rare but affects young patients. Active surveillance is now favoured over surgical resection due to high recurrence rates and extensive morbidity. Dedicated guidelines are required to ensure best outcomes.

Desmoid Type Fibromatosis of the Breast: Ten-Year Institutional Results of Imaging, Histopathology, and Surgery

Background

Desmoid type fibromatoses has proven to be a diagnostic and therapeutic challenge, as they often appear primarily as a carcinoma of the breast with a high recurrence risk.

Patients

A digital archive search was performed for the period from 2009 to the end of 2018. Inclusion criteria consisted of histological examination of at least the surgical specimen in the reference pathology department and at least a second opinion diagnosis in the reference radiology department.

Results

A total of 14 women and 1 man underwent surgery on desmoid type fibromatosis of the breast. The average patient age was 49 years (range: 22-72 years). The mean tumor size was 2.2 cm (range: 0.8-4.2 cm). The tumor was detectable in mammography in 12 out of 13 patients and in all 15 patients in sonography. MRI was performed preoperatively in 6 patients; in all of the patients, the tumor was visualized with inhomogeneous contrast enhancement. In the imaging procedures, all desmoid type fibromatoses were classified as suspicious. Performing the core biopsy, preoperative histology confirmed desmoid fibromatosis in 12 out of 15 patients. Nuclear stain for ß-catenin was positive in 7 out of 10 patients. Negative staining was found for AE1/A3 in 10 out of 10 and CD34 in 12 out of 12 patients. In all of the patients, a single-stage operation without the detection of border-forming tumor margins was performed. The follow-up interval ranged from 16 to 96 months (mean: 44.86 months, median: 43 months). In this follow-up period, no patient was diagnosed with desmoid tumor recurrence.

Conclusion

In imaging, desmoid type fibromatosis of the breast has typical malignancy-related criteria. Extensive preoperative diagnostics enable the planning of complete primary excision of the lesion and reduce the recurrence risk.

Desmoid tumours in the surveillance era: What are the remaining indications for surgery?

The treatment of desmoid tumours (DTs) has greatly evolved in recent years, and surgery is no longer considered a first-line treatment. Percutaneous biopsy with molecular analysis for beta-catenin or APC gene mutation provides a certain diagnosis. After imaging, a specialized multidisciplinary tumour board (MDT) addresses the following therapeutic strategy. As more than half of patients stabilize or regress, despite initial progression, active surveillance is offered to most patients as the first option. Surgery is proposed for complications such as perforation and occlusion, which sometimes are the first manifestations of the disease. In these cases, limiting surgery to the treatment of complications and leaving the tumour in place is possible if significant bowel sacrifice is needed, especially in patients with previous colectomy for polyposis. Medical therapy is discussed by the MDT in cases of functional or life-threatening masses and is preferred to local treatments that could be mutilating and often incomplete. First-line surgery is now contraindicated in cases of incomplete unplanned surgery, recurrence, pregnancy or DTs occurring in familial adenomatous polyposis (FAP). The best indications of second-line surgery are significantly progressing disease when morbidity is acceptable, such as parietal locations. Medical and other locoregional treatments (radiotherapy, isolated limb perfusion and cryotherapy) should be considered by the MTB when surgery might cause sequelae.

[Desmoid tumors: Are there still any surgical indications?]

After an adapted imaging, the diagnosis of a desmoid tumor (DT) is provided by a percutaneous microbiopsy, with a molecular analysis for beta-catenin or APC gene mutation. The therapeutic strategy must be decided in a specialized multidisciplinary tumor board (MTB). Surgery is no longer the first-line treatment for a DT. Except within a surgical complication, active surveillance is offered to the majority of patients, since more than half stabilize or regress after an initial progression, whether the location is peripheral or intra-abdominal. If the localization and/or volume are likely to be functional or life-threatening, medical induction therapy is discussed in MTB, before a local treatment whose potential sequelae would be definitive. Incomplete unplanned resection, recurrence, pregnancy or desmoids occurring in a polyposis context are no longer routine surgical indications. In an emergency setting (occlusion, peritonitis), it is discussed to treat only the mechanical complication and leave the DT in place, if its resection would lead to too much digestive resection, especially in patients who have already undergone colectomy for polyposis. The best indications for surgery are patients who have parietal locations with significant and documented progression, because surgery can be easily completed at the cost of an acceptable morbidity. In localizations where surgery would cause sequelae, medical treatment or other regional loco treatments are discussed in MTB.