Extra-abdominal desmoid tumours: a review of the literature

Large Multicentric Synchronous Extra-Abdominal Fibromatosis of the Leg and Foot: A Case Report

Extra-abdominal fibromatosis is an uncommon, benign locally aggressive fibrous soft-tissue tumor that usually occurs in the shoulders, chest wall, back, thigh, and head and neck affecting the young adult population. It is commonly located in the subcutaneous tissue and may infiltrate the adjacent skeletal muscles. We hereby report a rare case of a large extra-abdominal fibromatosis of the leg and foot in a 38-year-old woman. The patient presented with a large voluminous lesion clinically and on imaging, which was difficult to diagnose. Magnetic resonance imaging (MRI) was very helpful in diagnosing the lesion. It revealed a large relatively well-defined, lobulated hypointense mass in the posterior compartment of the leg with extension into the lower thigh and foot with local infiltration into the gastrocnemius and soleus muscles. An incisional biopsy was performed, and the mass was diagnosed on pathological examination as a spindle-shaped fibroblast proliferation suggesting extra-abdominal fibromatosis.

Extra‑abdominal recurrent aggressive fibromatosis: A case series and a literature review

Aggressive fibromatosis is a rare clonal proliferative tumor arising from mesenchymal cells in the fascia and musculoaponeurotic structures. The aim of the present study was to describe several cases of extra-abdominal recurrent aggressive fibromatosis. The present study was a single-center retrospective case series of patients with recurrent aggressive fibromatosis. The cases were managed at a single private facility. A total of 9 patients with recurrent fibromatosis were included. The mean and median ages of the patients were 29 and 30 years, respectively. In total, two thirds (66.67%) of the cases were female. A negative previous medical history was reported in 7 cases (77.7%), and diabetes and hypertension were reported in 1 case (11.1%). Overall, only 1 case (11.1%) had a family history of breast fibromatosis. The time interval between primary tumor resection and recurrent presentation was 28 months. In 6 cases (66.7%), the tumor was located in the extremities. Pain was the most common presenting symptom in 6 cases (66.7%). All patients had their recurring tumor surgically removed, followed by radiation in 5 cases. The resection margin was positive in 4 cases (44.4%). Each patient was subjected to a careful three-month follow-up for recurrences. On the whole, the present study demonstrates that despite the fact that several therapeutic approaches for extra-abdominal recurrent aggressive fibromatosis have been described in the literature, there is a significant likelihood of recurrence following resection.

Aggressive gluteal fibromatosis: a rare case associated with spontaneous superior gluteal artery pseudoaneurysm

Deep fibromatosis is a locally aggressive neoplasm commonly involving the extremities. Several authors have described imaging features and complications associated with deep fibromatosis. We present the case of a 33-year-old man who presented with a right gluteal fibrous mass identified on magnetic resonance imaging (MRI), which was associated with a pseudoaneurysm originating from the right superior gluteal artery on serial follow-up with MRI and computed tomography. No intervention was done, and after conservative management, spontaneous thrombosis of the pseudoaneurysm was developed. Such imaging finding is the first report of a spontaneous development of pseudoaneurysm caused by deep fibromatosis, which could be a life-threatening condition and should be considered when dealing with deep fibromatosis and deciding on the appropriate treatment.

A Rare Paraspinal Desmoid Tumour following Instrumented Scoliosis Correction in an Adolescent

Desmoid tumours are benign neoplasms of myofibroblasts, often occurring after soft-tissue trauma. Rarely, desmoid tumours can occur following operative intervention, including spine surgery. In this case report, we describe the first reported case of desmoid tumour following scoliosis corrective surgery in an adolescent.

Brachial Plexus Desmoid Tumor: Care for Functional Preservation

Desmoid tumors are a rare, locally invasive, non-metastasizing tumor of mesenchymal origin. Most of such tumors occur sporadically, but some arise as part of germline adenomatous polyposis coli mutations. They tend to aggregate in the abdomen, thorax, extremities, and the head and neck region. They are challenging to treat, with a high rate of recurrence even if achieving negative margins. We present the case of an 18-year-old woman with a desmoid tumor involving her brachial plexus. A non-oncological resection was performed, with a focus on functional preservation. Residual disease is being treated with β-catenin inhibitor and monitored with serial MRI.

The Management of Desmoid Tumors: A Retrospective Study of 30 Cases

Objectives

Desmoid tumor also called aggressive fibromatosis is a rare type of benign tumor. It is a mesenchymal malignancy without metastatic potential. The standard management is resection, but other options including observation may be discussed. Desmoid-type fibromatosis may occur throughout the body, but the abdominal wall is the most common site. The aim of our study was to assess the clinicoepidemiological profile, prognostic factors, and treatment outcome of desmoid tumors.

Methods

A monocentric retrospective study was conducted over a period of 19 years between February 2000 and November 2019 at the oncology department of Salah Azaïz Institute. Our study concerns 30 patients with desmoid tumor. All data regarding patients were obtained from the medical record.

Results

Thirty patients were included. The median age was 35 years with a female predominance (sex ratio = 0.07). A palpable mass was the most common complaint (n = 27). Median tumor size was 5 cm. The principal site of involvement was the abdominal wall (n = 14). Surgery was performed in 27 patients. The histopathology reports listed 14 (52%) cases with negative margins and 13 (48%) cases with positive margins. Radiation therapy was performed in 2 patients. One patient received tamoxifen. Local recurrence occurred in 11 patients. Two patients died of their desmoid tumor. Abdominal wall tumors have less risk of recurrence compared with other sites (p=0.047). Macroscopic margin involvement (R2) was the only prognostic factor influencing disease-free-survival (p=0.034).

Conclusion

Desmoid tumors are aggressive tumors with a tendency for local recurrence. Abdominal wall tumors have less risk of recurrence. Macroscopic margin involvement was the only prognostic factor that affects disease-free-survival.

3D Reconstruction Model of an Extra-Abdominal Desmoid Tumor: A Case Study

In recent years, three-dimensional reconstruction (3DR) models have become a standard tool in several medical fields such as education, surgical training simulation, patient–doctor communication, and surgical planning. Postoncologic reconstructive surgery in thoracic diseases might benefit from 3DR models; however, limited data on this application have been published worldwide. In this paper, the aim was to report our experience with 3DR modeling to determine resection and plan the surgical reconstruction in a patient with a desmoid tumor of the chest wall. For a better understanding of the case study, we describe all the steps from acquiring computed tomography (CT) scans to the final 3D rendering. A 68-year-old, non-smoking man presented at our outpatient department with painless swelling of the right anterobasal chest wall. A thorax–abdomen–brain CT scan revealed homogenous solid tissue with a dense mass measuring 80 mm × 62 mm. The final 3D model was evaluated by the surgical team (three medical doctors), who found the model to be powerful. Based on the results and the accuracy of the model, the multidisciplinary team decided that the tumor was resectable. Consequently, a surgical plan based on the 3D model was developed to perform chest wall reconstruction after radical resection. The patient underwent right anterolateral thoracotomy at the seventh intercostal space, which confirmed the CT scan findings and revealed infiltration of the serratus muscle and medial portion of the diaphragm. A radical tumor en bloc resection with chest wall and diaphragm resection was performed. The full-thickness chest wall and diaphragm defects were reconstructed using two separate biological patches of a porcine dermal collagen implant (Permacol™ Surgical Implant). Postoperative X-ray revealed unremarkable findings; the patient had an uneventful recovery and was discharged 6 days after surgery. This case study illustrates that 3DR models enable a personalized approach to the treatment of desmoid tumors. Therefore, this approach should be developed further and studied systematically.

Desmoid fibromatosis following surgical resection of spinal meningioma

A 42-year-old female patient with a history of cervicothoracic junction meningioma World Health Organization grade I, resected in early 2011, was admitted to the hospital with intractable headache and lower extremity weakness. Magnetic resonance imaging (MRI) showed an epidural mass compressing the spinal cord at the prior surgical site, which was interpreted as recurrent meningioma. Following surgical resection, histopathological analysis revealed desmoid fibromatosis (desmoid tumor). In retrospect, dynamic contrast-enhanced magnetic resonance imaging performed prior to surgery should have allowed for prospective exclusion of meningioma as the recurrent mass and suggested an alternative diagnosis such as post-traumatic desmoid fibromatosis or the need for biopsy to confirm diagnosis.

Percutaneous cryoablation for the treatment of extra-abdominal desmoid tumors

Background

Desmoid tumors are rare locally invasive, benign neoplasms that develop along aponeurotic structures. Current treatment is complicated by associated morbidity and high recurrence rates.

Methods

A retrospective, single‐institution review identified 23 patients (age: 16‐77) with extra‐abdominal desmoid tumors who received CT‐guided percutaneous cryoablation as either a first‐line (61%) or salvage (39%) treatment in 30 sessions between 2014 and 2018. Median maximal lesion diameter was 69 mm (range: 11‐209). Intent was curative in 52% and palliative in 48%. Contrast‐enhanced cross‐sectional imaging was obtained before and after treatment in addition to routine clinical follow‐up.

Results

Technical success was achieved in all patients. The median follow‐up was 15.4 months (3.5‐43.4). Symptomatic improvement was demonstrated in 89% of patients. At 12 months, the average change in viable volume was  −80% (range −100% to  + 10%) and response by modified response evaluation criteria in solid tumors (mRECIST) was CR 36%, PR 36%, and SD 28% No rapid postablation growth or track seeding was observed. Four patients underwent repeat cryoablation for either residual or recurrent disease. Two patients sustained a major procedural complication consisting of significant neuropraxia.

Conclusion

Cryoablation for desmoid tumors demonstrates a high degree of symptom improvement and local tumor control on early follow‐up imaging with relatively low morbidity.

Orbital Desmoid-Type Fibromatosis: A Case Report and Literature Review

Purpose

Desmoid-type fibromatosis is a benign fibrous neoplasia originating from connective tissue, fascial planes, and musculoaponeurotic structures of the muscles. Currently, there is no evidence-based treatment approach available for desmoid fibromatosis. In this article, a case of a patient in the pediatric age affected by desmoid fibromatosis localized in the orbit is presented. The aim of the article is to describe this unusual and rare location for the desmoid fibromatosis and outline the principle phases in the decision-making process and the therapeutic alternatives for a patient affected by desmoid fibromatosis.

Methods

The protocol of this review included study objectives, search strategy, and selection criteria. The primary end point of this study was to analyze the head and neck desmoid fibromatosis. The secondary end point was to identify the available therapies and assess their specific indications.

Results

The mean age of patients was 18.9 years ranging from 0 to 66, and 52% were female. A bimodal age distribution was observed, and two age peaks were identified: 0–14 years (57%) and 28–42 years (18%). The most common involved areas were the mandible (25%) followed by the neck (21%). In 86% of the cases, the treatment was the surgical resection of the disease, and only in 5% of the cases, the surgical resection was followed by adjuvant radiotherapy.

Conclusion

The orbital location is extremely rare, especially in the pediatric population. The management of desmoid fibromatosis is based on the function preservation and the maintenance of a good quality of life, but in case of symptomatic patients or aggressive course of the disease or risk of functional damages, the surgical approach may be considered. Therapeutic alternatives to surgical resection are radiotherapy and systemic therapy.

Desmoplastic fibroma versus soft-tissue desmoid tumour of forearm: a case series of diagnosis, surgical approach, and outcome

We report a case series of aggressive fibromatosis of the forearm and discuss the differentiation criteria of overlapped intra- or extra-osseous origin of aggressive fibromatosis, surgical approach, and outcome. Ten cases of aggressive fibromatosis of the forearm were evaluated. When there was no involvement of vital adjacent structures, such as nerves, vessels, and tendons, en-bloc excision was performed for the removal of the soft-tissue mass. Bone involvement was observed in nine cases. Intercalary allograft was performed whenever one of the forearm bones was involved (six cases), while extensive curettage was used if both forearm bones were affected (three cases). The mean Musculoskeletal Tumor Society Score was 90%, ranging from 80% to 97%. Limited forearm rotation was the most frequent complication. Three local recurrences were observed, none with intercalary allograft reconstruction. We conclude that the extensive curettage of the involved bone results in a higher risk of local recurrence compared with intercalary allograft.

LEVEL OF EVIDENCE

IV.

Gardner Fibroma: Clinical and Histopathologic Implications of Germline APC Mutation Association

The proportion and clinical characteristics of Gardner fibromas (GAFs) that are sporadic versus familial adenomatous polyposis (FAP)-associated have not been clearly established. We report on 7 patients diagnosed with GAF who underwent APC sequencing and duplication/deletion testing. Three (43%) were found to have underlying APC germline perturbations consistent with FAP; these patients had multifocal (1) or large; unresectable (2) GAFs. The 4 patients with negative APC testing each had a single resectable GAF. β-catenin reactivity was noted in all FAP-associated GAFs and in 1/4 APC wild-type cases. FAP-associated GAFs may be less common than sporadic GAFs and can demonstrate clinically distinct features.

Splenic Artery Aneurysm Invaded by Desmoid-Type Fibromatosis

Despite the benign histologic appearance and negligible metastatic potential, desmoid tumors can be locally aggressive, invading into adjacent structures and organs. We report an unusual case of desmoid-type fibromatosis causing the death of an otherwise healthy individual by rupturing the splenic artery.

Treatment of Aggressive Pelvic Fibromatosis With Interferon

BACKGROUND

Fibromatosis is a rare, noninvasive but aggressive tumor. The tumor displaces tissue by "pushing" the normal structures aside. Optimal treatment should be individualized.

CASE

A 35-year-old woman presented with a recurrent fibromatosis, which filled the vagina and extended into the pelvis. The classical surgical removal would have had a high morbidity. Therefore, it was decided, after shared decision-making, to opt for treatment with interferon. The side effects of the therapy were tolerable, and a complete regression of the fibromatosis was achieved. At present, 13 years after the diagnosis and 7 years after discontinuation of the therapy, the patient is well with no signs of disease.

CONCLUSION

Interferon may be considered as primary treatment for extensive pelvic fibromatosis.

Extra-abdominal desmoid fibromatosis: A review of management, current guidance and unanswered questions

Extra abdominal desmoid fibromatosis is a complex condition with many recognised treatments including active observation, hormonal therapy, chemotherapy, radiotherapy and surgical resection. There is large variation in the natural history of individual desmoid tumours, with some cases progressing aggressively and others regressing spontaneously when observed alone. This combined with an absence of accurate clinical predictors of a desmoid tumour's behaviour has led to difficulties in identifying which patients would benefit most from aggressive treatment, and which could be adequately managed with a policy of active observation alone. This review explores the aetiology and common presentation of extra-abdominal desmoid fibromatosis including the condition's histopathological, clinical and radiological characteristics. The current evidence for potential predictors of desmoid tumour behaviour is also reviewed, along with the indications and evidence for the multitude of treatments available. We also summarise the published guidelines that are currently available for oncologists and surgeons managing extra-abdominal desmoid fibromatosis, and highlight some of the unanswered questions that need to be addressed to optimise the management of this condition.

Desmoid tumors complicating Familial Adenomatous Polyposis: a meta-analysis mutation spectrum of affected individuals

Background

Desmoid tumors are a group of benign, invasive, solid tumors that are relatively rare in the general population, but can occur in up to 21 % of patients with Familial Adenomatous Polyposis (FAP). They can be difficult to treat and have high rates of recurrence even after resection. Our goal with this study was to identify the genetic mutations that put certain patients with FAP at high risk for desmoid tumors and could be future targets for research.

Methods

We performed a search in Pubmed, Ovid Medline and Embase to identify subjects with desmoid tumors and FAP. As a reference group for APC mutations in the unselected FAP population, we used the UMD-APC database referenced in the Orphanet portal which includes APC mutation data on 2040 individuals with FAP.

Results

Mutations were able to be broken down into 7 regions based on previously published data. Mutations in the APC gene from codons 1310 to 2011 were the most common region encompassing 48 % of published desmoid cases and 40 % of the reference population. It had a slightly elevated odds ratio of 1.4 that was statistically significant along with codon region 543-713 that had an odds ratio of 2.0. Using a combination of p-value and CI, the remaining 5 regions did not meet statistical significance as either the p >0.05 or the CI included 1.0. The most common point mutation found was codon 1309 (13.1 %), but it was also the most commonly found mutation in our reference population (12.9 %) and had an odds ratio of 1.0.

Conclusions

There is an increased risk for desmoid tumors in individuals with APC mutations between codons 543-713 and 1310-2011 when compared to a reference population. These patients may benefit from further study to develop surveillance protocols that could improve outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0306-2) contains supplementary material, which is available to authorized users.

Five years of local control of subscapularis aggressive fibromatosis managed by surgery and imatinib: a case report

Introduction

Imatinib, a tyrosine kinase inhibitor, is a major therapeutic option for the management of unresectable aggressive fibromatosis. Unfortunately, for most patients of low or very low average income countries, surgery often is the first treatment option. This is related to unavailability of chemotherapy or targeted therapy, and to a lack of financial resources or surgeons’ lack of knowledge of other therapeutic options.

Case presentation

In 2010, a 26-year-old Moroccan man was referred to our oncology and radiotherapy center by his surgeon for the management of a recurrent tumor of his right subscapularis muscle. Before his assessment in our center, two resections were performed by his surgeon after performing an incision biopsy and magnetic resonance imaging. Postoperative magnetic resonance imaging was performed and showed a right axillary nodule size 2.1cm regarding a collection with a residual tumor. We decided to administer imatinib 400mg daily by mouth. Clinical and magnetic resonance imaging evaluation were performed regularly and reported a stable tumor. We reported no adverse side effects to imatinib regarding Common Terminology Criteria for Adverse Events grading.

Conclusions

Recurrences are high during aggressive fibromatosis management. Systemic treatment with imatinib for unresectable or recurrent tumors with positive c-KIT could be the best therapeutic option. In our case report, the patient was stabilized with imatinib for 30 months and he had a very good quality of life.

Recurrent desmoid tumor of the mediastinum: A case report

Desmoid tumors (DTs) are rare, benign soft-tissue tumors that have the potential for local invasion, but not for metastasis. The tumors are commonly characterized by a palpable mass, but present a variable and unpredictable clinical course. The current study presents the case of a giant mediastinal DT exhibiting lung involvement. A 50-year-old female was referred to the West China Hospital (Chengdu, Sichuan, China) due to a recurrent DT that was identified one year following radical surgery. The patient subsequently received radiation therapy. The DT arose from the mediastinum, unlike the usual presentation, and recurrence presented as extensive invasion into the lung tissue, almost being misdiagnosed as lung cancer with brain metastasis. Tumor recurrence was diagnosed through contrast-enhanced computed tomography and histological examination of the tumor. A routine follow-up revealed no further tumor progression at 9 months post-admission. Taking into account the unpredictable treatment complications, recurrent DTs can be managed simply and efficiently. A ‘wait-and-see’ policy could be a viable therapeutic option for this disease.

Bone and soft tissue ablation

Bone and soft tissue tumor ablation has reached widespread acceptance in the locoregional treatment of various benign and malignant musculoskeletal (MSK) lesions. Many principles of ablation learned elsewhere in the body are easily adapted to the MSK system, particularly the various technical aspects of probe/antenna design, tumoricidal effects, selection of image guidance, and methods to reduce complications. Despite the common use of thermal and chemical ablation procedures in bone and soft tissues, there are few large clinical series that show longitudinal benefit and cost-effectiveness compared with conventional methods, namely, surgery, external beam radiation, and chemotherapy. Percutaneous radiofrequency ablation of osteoid osteomas has been evaluated the most and is considered a first-line treatment choice for many lesions. Palliation of painful metastatic bone disease with thermal ablation is considered safe and has been shown to reduce pain and analgesic use while improving quality of life for cancer patients. Procedure-related complications are rare and are typically easily managed. Similar to all interventional procedures, bone and soft tissue lesions require an integrated approach to disease management to determine the optimum type of and timing for ablation techniques within the context of the patient care plan.

Prognostic factors for desmoid tumor: a surgical series of 233 patients at a single institution

Desmoid tumors are rare soft tissue tumors with limited data on their management and prognosis. We sought to determine the rates of recurrence after surgery for desmoid tumors and analyze factors predictive of recurrence-free survival (RFS). From February 1976 to October 2011, 233 consecutive patients with desmoid tumors who underwent macroscopically complete resection were included in this study. Clinicopathologic and treatment characteristics were evaluated to determine predictors of recurrence. Patterns of presentation included primary (n = 156, 67.0 %) and locally recurrent (n = 77, 33.0 %) disease initially treated elsewhere. Most patients had a R0 resection (n = 169, 72.5 %). In addition to surgery, 43 (18.5 %) patients received radiotherapy and 10 (4.3 %) patients received systemic therapy. Median follow-up was 54 months; recurrence disease was observed in 62 (26.6 %) patients. The estimated 5- and 10-year RFS was 74.2 % (95 % confidence interval (CI), 68.3-80.1) and 70.7 % (95 % CI, 64.2-77.2), respectively. Factors associated with worse RFS were tumor size larger than 5 cm (hazard ratio (HR) = 3.757; 95 % CI, 1.945-7.259; p < 0.001), extra-abdominal tumor location (abdominal wall referent; HR = 3.373; 95 % CI, 1.425-7.984; p = 0.006), and R1 resection status (HR = 1.901; 95 % CI, 1.140-3.171; p = 0.014). Patients were grouped according to the number of unfavorable prognostic factors; the 10-year RFS rates of patients with zero, one, two, and three prognostic factors were 100, 86.9, 48.5, and 34.4 %, respectively (p < 0.001). Regardless of primary or recurrent disease, surgical resection remains central to the management of patients with desmoid tumors. However, there are clearly different prognostic subgroups that could benefit from different therapeutic strategies, and a wait-and-see policy is a possible option for a subset of patients.

Desmoid tumor arising from omohyoid muscle: The first report for unusual complication after transaxillary robotic thyroidectomy

BACKGROUND

Transaxillary robotic (TAR) thyroidectomy has been performed for better aesthetic results by many surgeons. In this report, we describe a rare case of a desmoid tumor developed after TAR thyroidectomy, which is speculated to be a late-term complication.

METHODS AND RESULTS

A 61-year-old woman with a history of papillary microcarcinoma had experienced a large left neck mass that had grown over 2 years. The patient underwent TAR thyroidectomy (right lobectomy and isthmectomy) via the right axilla almost 2.5 years previously. Physical examination revealed a 6-cm, firm mass fixed to the left anterior neck. The mass was fixed to the omohyoid muscle. The 5.9- × 4.7- × 4.5-cm tumor with the surrounding muscles was excised in an en bloc fashion. Pathologic examination confirmed the diagnosis of a desmoid tumor.

CONCLUSION

This case suggests that desmoid tumors could develop late after TAR thyroidectomy. Thus, careful observation of the surgical wound may be necessary after TAR thyroidectomy.

Extra-abdominal desmoid fibromatosis--a sarcoma unit review of practice, long term recurrence rates and survival

INTRODUCTION

Desmoid fibromatosis (DF) carries a significant morbidity and a recognised mortality. Despite this there are currently limited diagnostic or treatment algorithms specific to cases of extra-abdominal DF. Historically surgical excision has formed the cornerstone of treatment. Recently however a paradigm shift has meant many practitioners now adopt a more conservative approach, placing emphasis on active surveillance, function preserving resections, and non-surgical oncologic therapies.

METHODS

We performed an 8-year retrospective review of all cases of extra-abdominal DF managed within our region to assess the consistency of diagnostics, management and long-term outcome.

RESULTS

47 eligible cases were identified. Mean age at diagnosis was 41.3 years (1-81 years). Disease location and speciality of diagnosing practitioners were varied. Management was generally inconsistent. Variation was seen in imaging, biopsy techniques, MDT involvement and management. At a median follow up of 4.9 years our local recurrence rate was 19%.

DISCUSSION

The optimal management of DF is unknown. This has led to a lack of formalised guidance for practitioners managing this challenging condition, resulting in inconsistencies and areas for improvement in current management. We propose a diagnostic pathway which may improve consistency of care, reduce potentially unnecessary surgery and the associated morbidity, and significantly increase the rate of complete (R0) surgical resections when surgery is deemed appropriate whilst not significantly worsening oncological outcome. Specifically we propose all cases should be imaged appropriately (usually with MRI), undergo a planned biopsy (by radiologically guided core needle biopsy) and be managed centrally in conjunction with multidisciplinary sarcoma units.

[Intraabdominal desmoid tumors in familial adenomatous polyposis]

Desmoid tumors are currently the main cause of morbidity and mortality in patients with familial adenomatous polyposis. More than 10% of these patients will develop these tumors during their lifetime and more than a third will suffer their consequences. The main risk factors for their development are female sex and abdominal surgery. The most frequent localization is intraabdominal. The therapeutic approach to these tumors has changed, and the surgical treatment of choice is currently the subject of debate. If a watch and wait approach is adopted, more than 50% of tumors will prove to be indolent. Therefore, the therapeutic strategy should be based on clinical presentation and should be decided by a multidisciplinary team working in a center with experience of these tumors. The present article proposes a prognostic classification to guide the therapeutic approach.