Aggressive fibromatosis. Pathology. 2014;46:135-140. [PMID: 24378386 DOI: 10.1097/pat.0000000000000045]

Desmoid fibromatosis-a diagnostic dilemma

PURPOSE

Desmoid fibromatosis in head and neck is infrequent and poses a significant challenge to the clinicians due to its non-specific characteristics.

METHODS

This case report focuses on a 69-year-old male who presented to a tertiary healthcare center in Karnataka, India with a swelling in the oral cavity.

RESULTS

Despite initial suspicions of malignancy based on clinical examination and findings on computed tomography imaging, subsequent histopathology and immunohistochemistry revealed an unexpected finding.

CONCLUSION

The case highlights the importance of clinical suspicion and histopathological evaluation as well as the need for greater awareness to facilitate early diagnosis and appropriate management of desmoid fibromatosis. We also present a literature review of varied presentations of desmoid tumors afflicting various subsites of the head and neck.

Case report: Rapidly progressive desmoid tumor after surgery for esophagogastric junction cancer and slowly progressive primary desmoid tumor: a report of two cases and literature review

Background

Desmoid tumor (DT) is a rare locally aggressive but non-metastatic mesenchymal soft tissue neoplasm that predominantly occurs in the abdominal wall, abdominal cavity, and extremities. Its occurrence in the mesentery is relatively uncommon.

Case reports

This article reports two cases of desmoid tumor treated at the Department of Gastrointestinal Surgery, Weifang People's Hospital. The first case was a 59-year-old male patient who had previously undergone surgery for esophagogastric junction cancer. Postoperatively, he developed an intra-abdominal mass that rapidly increased in size within three months. The second case was a 60-year-old male patient who incidentally discovered a mass in the left lower abdomen. Both patients underwent surgical treatment, and the postoperative pathological diagnosis was mesenteric desmoid tumor.

Conclusion

The treatment of desmoid tumor remains challenging. Simple surgical resection often yields unsatisfactory outcomes, and the efficacy of adjuvant radiotherapy and chemotherapy is also limited. Further research and clinical practice are necessary to improve diagnostic and therapeutic strategies, aiming to enhance patient survival and quality of life.

[Aggressive Fibromatosis: Retrospective Analysis of 110 Patients]

Aggressive fibromatosis, histologically classified as benign due to the absence of metastasis, is characterised by locally invasive and destructive growth with high recurrence rates after resection. For this reason, prognostic recurrence factors, in particular the extent of resection, are much debated, and treatment decisions seem challenging for interdisciplinary tumour conferences. Between the years 2000 and 2020, 110 patients with aggressive fibromatosis of the extremities or trunk received surgical treatment at BG University Hospital Bergmannsheil (Bochum, Germany). Univariate analyses were performed to detect any potential prognosis factors. The median follow-up time was 5.9 years. A total of 57 (51.8%) of these patients developed recurrence during this period. The 5-year recurrence-free survival was 52.9% (95% CI: 42.4-62.3) in the entire cohort. In R0-resected patients, the 5-year recurrence-free survival (RFS) was significantly better (p<0.001) at 69.2% compared with patients with R1 or R2-resected tumours (32.6%). Beyond that, no other significant influencing factors were identified. The results of this study indicate that R0 resection or R0 resectability were associated with a significantly better local control. The therapeutic recommendation for resection should be made individually by an interdisciplinary tumour board in due consideration of tumour progression, possible therapeutic alternatives, and foreseeable functional impairment.

Desmoid type fibromatosis of the distal pancreas: A case report

A 23-year-old Korean female presented epigastric pain of two-months’ duration. She had a laparoscopic ovarian cyst excision 8 months previously. Clinical examination was normal. An abdominal computed tomogram (CT) demonstrated a 10-cm solid mass in the distal pancreas, with signs of splenic artery and vein occlusion, gastric and transverse colon invasion. Operative findings showed a mass involving distal pancreas, invasive to the posterior wall of the antrum of the stomach and transverse colon and 4th portion of the duodenum without lymph node involvement. The surgery consisted of a distal pancreatectomy, splenectomy and combined partial resection of the stomach, transverse colon and 4th portion of the duodenum. The immunohistochemistry and histopathological features were consistent with a confirmed diagnosis of intra-abdominal desmoid type fibromatosis (DTF). The prognosis of pancreatic DTF is not known and she showed no recurrence or distant metastasis during a 3 year follow-up. Herein we report a rare case with an isolated, sporadic, and non-trauma-related DTF, located at the pancreatic body and tail.

Extra-abdominal desmoid tumor fibromatosis: a multicenter EMSOS study

Background

Extra-abdominal desmoid tumor fibromatosis (DTF) is a rare, locally aggressive soft tissue tumour. The best treatment modality for this patient cohort is still object of debate.

Questions/purpose

This paper aimed to (1) to compare the outcomes of DTF after different treatment modalities, (2) to assess prognostic factors for recurrence following surgical excision, and (3) to assess prognostic factors for progression during observation.

Methods

This was a retrospective multicenter study under the patronage of the European Musculoskeletal Oncology Society (EMSOS). All seven centres involved were tertiary referral centres for soft tissue tumours. Baseline demographic data was collected for all patients as well as data on the diagnosis, tumour characteristics, clinical features, treatment modalities and whether they had any predisposing factors for DTF.

Results

Three hundred eighty-eight patients (240 female, 140 male) with a mean age of 37.6 (±18.8 SD, range: 3–85) were included in the study. Two hundred fifty-seven patients (66%) underwent surgical excision of ADF, 70 patients (18%) were observed without therapy, the residual patients had different conservative treatments. There were no significant differences in terms of tumour recurrence or progression between the different treatment groups. After surgical excision, younger age, recurrent disease and larger tumour size were risk factors for recurrence, while tumours around the shoulder girdle and painful lesions were at risk of progression in the observational group.

Conclusion

Local recurrence rate after surgery was similar to progression rates under observation. Hence, observation in DTF seems to be justified, considering surgery in case of dimensional progression in 2 consecutive controls (3 and 6 months) and in painful lesions, with particular attention to lesions around the shoulder girdle.

Development, Validation, and Visualization of A Web-Based Nomogram for Predicting the Recurrence-Free Survival Rate of Patients With Desmoid Tumors

Background

Surgery is an important treatment option for desmoid tumor (DT) patients, but how to decrease and predict the high recurrence rate remains a major challenge.

Methods

Desmoid tumor patients diagnosed and treated at Tianjin Cancer Institute & Hospital were included, and a web-based nomogram was constructed by screening the recurrence-related risk factors using Cox regression analysis. External validation was conducted with data from the Fudan University Shanghai Cancer Center.

Results

A total of 385 patients were identified. Finally, after excluding patients without surgery, patients who were lost to follow-up, and patients without complete resection, a total of 267 patients were included in the nomogram construction. Among these patients, 53 experienced recurrence, with a recurrence rate of 19.85%. The 3-year and 5-year recurrence-free survival (RFS) rates were 82.5% and 78%, respectively. Age, tumor diameter, admission status, location, and tumor number were correlated with recurrence in univariate Cox analysis. In multivariate Cox analysis, only age, tumor diameter and tumor number were independent risk factors for recurrence and were then used to construct a web-based nomogram to predict recurrence. The concordance index (C-index) of the nomogram was 0.718, and the areas under the curves (AUCs) of the 3-year and 5-year receiver operating characteristic (ROC) curves were 0.751 and 0.761, respectively. In the external validation set, the C-index was 0.706, and the AUCs of the 3-year and 5-year ROC curves are 0.788 and 0.794, respectively.

Conclusions

Age, tumor diameter, and tumor number were independent predictors of recurrence for DTs, and a web-based nomogram containing these three predictors could accurately predict RFS (https://stepforward.shinyapps.io/Desmoidtumor/).

Misdiagnosis of ligamentoid fibromatosis of the small mesenteric: A case report

BACKGROUND

Ligamentoid fibromatosis is a rare borderline tumor that occurs in the muscles, fascia, and aponeurosis. It is a kind of soft tissue tumor of fibrous origin, also known as invasive fibromatosis, desmoid fibroma, neurofibromatosis, etc. The tumor is between benign and malignant tumors and rarely has distant metastasis. Its characteristics are mainly local invasion, destruction and growth and easy recurrence. The World Health Organization defines it as a fibroblast cloning value-added lesion originating from deep soft tissue, which causes local invasion and growth leading to tissue reconstruction, extrusion and destruction of important structures and organs. The incidence rate accounts for 0.03% of all tumors and less than 3% of all soft tissue tumors. Definite diagnosis mainly depends on postoperative pathology. Surgical resection is still the main way to treat the disease, and a variety of nonsurgical treatment methods are auxiliary. Combined treatment can effectively reduce the risk of postoperative recurrence.

CASE SUMMARY

The patient is a 57-year-old female. One week ago, she accidentally found a mass in the left upper abdomen while lying flat. There was no abdominal pain and abdominal distention, no fever, no black stool and blood in the stool and no nausea and vomiting. She had a 10-year history of glaucoma on the left side, underwent hysterectomy for uterine fibroids 5 years ago, had no hypertension, heart disease, diabetes, hepatitis or tuberculosis, had no history of smoking and had been drinking for 20 years.

CONCLUSION

Accurate preoperative diagnosis is difficult, surgical resection is the main treatment, and a variety of nonsurgical treatment methods are auxiliary. Combined treatment can effectively reduce the risk of postoperative recurrence. The prognosis is still good, and the risk of recurrence of secondary surgery is greatly increased.

A Timely Oral Option: Single-Agent Vinorelbine in Desmoid Tumors

INTRODUCTION

Desmoid tumors (DT) are rare collagen-forming tumors that can exhibit locally aggressive patterns of behavior. The aim of this study was to evaluate the efficacy and safety of treatment of DT with single-agent oral vinorelbine.

MATERIALS AND METHODS

A retrospective review of patients treated with vinorelbine 90 mg orally on days 1, 8, and 15 of a 28-day cycle from January 2004 to July 2019 was performed. Response was assessed using RECIST version 1.1. Descriptive statistics were employed.

RESULTS

A total of 29 patients were included. Response rate was 20.7% (6/29), and clinical benefit rate (response by RECIST 1.1 and/or clinical symptom improvement) was 65.5% (19/29). No patient experienced grade 3 or above toxicity. Common toxicities were grade 1-2 nausea (14/26, 48.3%), fatigue (9/26, 31.0%), and diarrhea (4/26, 13.8%).

CONCLUSION

Single-agent oral vinorelbine is an effective, safe, and well-tolerated treatment for DT. It represents a new oral alternative for management of DT.

Multimodality imaging features of desmoid tumors: a head-to-toe spectrum

Desmoid tumors (DTs) are a rare and biologically heterogeneous group of locally aggressive fibroblastic neoplasm: their biological behavior spectrum ranges from indolent to aggressive tumors. DTs are classified as intra-abdominal, extra-abdominal, and within the abdominal wall lesions.It is well known that abdominal and extra-abdominal DTs are associated with familial adenomatous polyposis (FAP) and Gardner syndrome. Possible risk factors are prior trauma/surgery, pregnancy, and oral contraceptives.There was a real revolution in the management of DT: from aggressive first-line approach (surgery and radiation therapy) to a more conservative one (systemic treatment and "wait-and-see policy").In these clinical settings, radiologists play an important role for assessing lesion resectability, evaluating recurrence, monitoring the biological behavior if an expectant management is chosen, and assessing response to systemic treatment as well as to radiation therapy.Awareness of common locations, risk factors, and imaging features is fundamental for a correct diagnosis and an adequate patient management.

Soft Tissue Special Issue: Fibroblastic and Myofibroblastic Neoplasms of the Head and Neck

Fibroblastic and myofibroblastic neoplasms of the head and neck encompass a group of rare tumor types with often overlapping clinicopathologic features that range in biologic potential from benign to overtly malignant. Even neoplasms with no metastatic potential may provide significant therapeutic challenges in this region due to the unique anatomy of the head and neck. This review will cover the following entities, highlighting important clinical aspects of each neoplasm and then focusing on their characteristic histomorphology, immunophenotype, and molecular alterations: nodular and cranial fasciitis, fibrous hamartoma of infancy, nasopharyngeal angiofibroma, nuchal-type and Gardner fibromas, desmoid fibromatosis, dermatofibrosarcoma protuberans and giant cell fibroblastoma, solitary fibrous tumor, inflammatory myofibroblastic tumor, low-grade myofibroblastic sarcoma, infantile fibrosarcoma, low-grade fibromyxoid sarcoma, and sclerosing epithelioid fibrosarcoma. While some of these neoplasms characteristically arise in the head and neck, others are rarely described in this anatomic region and may therefore be particularly difficult to recognize. Distinction between these entities, however, is crucial, particularly as the molecular pathogenetic basis for these neoplasms are being rapidly elucidated, in some instances allowing for targeted therapeutic approaches.

Large desmoid tumors in familial adenomatous polyposis: a successful outcome

Desmoid tumors develop from connective tissue, fasciae, and aponeuroses, and may occur in the context of familial adenomatous polyposis or may arise sporadically; also, they may be extra-abdominal, intra-abdominal, or located in the abdominal wall. These benign tumors have a great aggressiveness with a high rate of local recurrence. Familial adenomatous polyposis is an inherited condition with autosomal dominant transmission, and is characterized by the development of multiple colonic and rectal adenomatous polyps, as well as desmoid tumors. We present the case of a 54-year-old woman with germline APC gene mutation, who underwent a total colectomy, subsequently developing two large infiltrative solid intra-abdominal lesions consistent with desmoid tumors. Medical treatment with Cox-2 inhibitors was initiated without result. She was submitted to resection for intestinal obstruction, but developed local recurrence. The lesions were also unresponsive to tamoxifen, and chemotherapy was initiated with dacarbazine plus doxorubicin, switching to vinorelbine plus methotrexate, achieving a good response in all lesions after 12 months. The approach to these intra-abdominal lesions should be progressive, beginning with observation, then a medical approach with non-steroidal anti-inflammatory drugs or with an anti-hormonal agent. Afterwards, if progression is still evident, chemotherapy should be started. Surgery should be reserved for resistance to medical treatment, in palliative situations, or for extra-abdominal or abdominal wall desmoids tumors.

MRI findings of low-grade fibromyxoid sarcoma: a case report and literature review

Background

Low-grade fibromyxoid sarcoma (LGFMS) is a distinctive slow growing soft tissue neoplasm, mostly affecting young individuals with no gender difference. It usually arises in deep soft tissue of the lower limbs and trunk, but few cases of LGFMS located in pelvis have been reported.

Case presentation

We describe the magnetic resonance imaging(MRI) features of LGFMS located in the anterior pelvic wall of a 21-year-old female and correlate them with clinicopathological features. The tumor was completely resected and there is no recidivism during the follow-up one year.

Conclusions

We report on the radiological findings of LGFMS with histological correlation. Awareness of the imaging features may be useful for the diagnosis of LGFMS and helpful to distinguish among mimics.

Desmoid type fibromatosis: A case report with an unusual etiology

Desmoid type fibromatosis (DTF) is a rare, locally invasive, non-metastasizing soft tissue tumor. We report an interesting case of DTF involving the pancreatic head of a 54-year-old woman. She presented with intermittent dysphagia and significant weight loss within a 3-mo period. Laboratory findings showed mild elevation of transaminases, significant elevation of alkaline phosphatase and direct hyperbilirubinemia, indicating obstructive jaundice. Computerized tomography of the abdomen revealed a mass in the head of the pancreas, dilated common bile duct, and dilated pancreatic duct. Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound showed a large hypoechoic mass in the head of the pancreas causing extrahepatic biliary obstruction and pancreatic ductal dilation. The patient underwent a successful partial pancreatico-duodenectomy and cholecystectomy. She received no additional therapy after surgery, and liver function tests were normalized within nine days after surgery. Currently, surgical resection is the recommended first line treatment. The patient will be followed for any recurrence.

[Soft tissue tumors in hereditary tumor syndromes]

Benign and malignant soft tissue tumors usually develop de novo without identifiable risk factors or predisposing conditions. However, in recent decades, soft tissue tumors have been increasingly recognized to be associated with diverse hereditary tumor syndromes as a consequence of germline mutations involving mainly tumor suppressor genes, but rarely also affecting proto-oncogenes. This is mainly the consequence of increasing application of modern genetic analysis tools, such as next-generation sequencing (NGS) and whole genome analyses. Syndrome-associated soft tissue tumors frequently show distinctive clinicopathological features and peculiarities that facilitate and potentially enhance their recognition and identification during routine surgical pathology practice. As it is not uncommon that pathologists are the first medical specialists to recognize a potential hereditary etiology of neoplastic diseases on the basis of specific pathological features, it is mandatory that pathologists be familiar with the main features that characterize those soft tissue tumors with inherited etiology, at least the most common and important of them. This review summarizes the main syndromes and their associated soft tissue tumors and discusses their characteristic pathological features that help in the recognition of hereditary syndromes.

Desmoid Fibromatosis Presenting as Deep Venous Thrombosis: A Case Report and Discussion

Patient: Male, 40

Final Diagnosis: Desmoid fibromatosis

Symptoms: Discomfort

Medication: —

Clinical Procedure: Surgery and radiotherapy

Specialty: Surgery

Iodine-125 Interstitial Brachytherapy for Pediatric Desmoid-Type Fibromatosis of the Head and Neck: A Case Report

Desmoid-type fibromatosis (DF) is a locally aggressive benign soft tissue tumor. It is rarely observed in the head and neck region and is particularly uncommon in the parotid gland. This report describes the case of a 32-month-old girl with DF of the head and neck. The tumor was resected with gross residual tumors. Recurrence occurred 3 months later and then the patient was treated with iodine-125 interstitial brachytherapy. The tumor was completely absent 6 months after brachytherapy. No recurrence was found 60 months after brachytherapy during follow-up. No severe toxicities or growth abnormalities were observed. Very-low-dose rate brachytherapy as the sole modality could be a reasonable alternative for the treatment of inoperable DF of the head and neck, which avoids the risk of cosmetic deformity caused by surgery, especially in pediatric patients. In addition, long-term follow-up is recommended.

Low-grade Nonrhabdomyosarcoma Soft Tissue Sarcoma: What is Peculiar for Childhood

BACKGROUND

Nearly half of soft tissue sarcomas are nonrhabdomyosarcomas (NRSTSs). The low-grade (LG) form comprises a heterogenous group of diseases that rarely metastasize but are known for local recurrence.

AIM OF THE STUDY

The aim of the study was to retrospectively evaluate pediatric LG-NRSTS with regard to demography, survival, and factors affecting outcome in Egyptian patients.

PATIENTS AND METHODS

The study reviewed 66 NRSTS patients who presented to the Pediatric Oncology Department, National Cancer Institute, Cairo University, between January 2008 and December 2013.

RESULTS

Out of the reviewed cases 32 patients had LG tumors and were eligible for analysis. The male to female ratio was 1:1 and the median age was 7.5 years (range, 1 mo to 18 y). Desmoid fibromatosis (N=18) showed frequent local recurrence and nearly half of this group was alive without disease. No recurrence of the disease occurred in the nonfibromatosis group (n=14) and all patients were alive and free of disease. The 5-year overall survival was 88% for the entire group of study patients versus 45% for event-free survival. Tumors >5 cm in diameter and fibromatosis histology subtype were associated with lower EFS.

CONCLUSIONS

LG-NRSTS generally has good prognosis, with overall survival reaching 90%. However, aggressive fibromatosis usually runs a poorer course in the form of high incidence of local recurrence and lower survival rates. This needs to be further assessed in larger prospective studies including novel therapies in addition to the current conventional modalities.

Proximal Interphalangeal Joint Fibromatosis After Pyrocarbon Implant Insertion: A Case Report

Background: Pyrocarbon implants represent an increasingly popular method to treat proximal interphalangeal joint dysfunction. To this point, no association has been shown between pyrocarbon biomaterials and fibromatosis. We present a potentially serious and destructive complication associated with pyrocarbon arthroplasty. Methods: We demonstrate a clinical case involving pyrocarbon arthroplasty and subsequent fibromatosis development in an otherwise healthy 23-year-old female. To present this association, we illustrate the diagnostic workup involved in a rapidly expanding soft tissue mass of the hand and explain the appropriate treatment. Results: Pyrocarbon arthroplasty was associated with development of locally destructive fibromatosis confirmed by histopathological examination. Treatment involved wide resection with preservation of local structures. Conclusion: We describe the first association between fibromatosis and pyrocarbon biomaterial. Due to fibromatosis destructive effects, clinicians should be aware of potential complications associated with these materials and know how to accurately diagnose and treat these lesions.

Early experience: high-intensity focused ultrasound treatment for intra-abdominal aggressive fibromatosis of failure in surgery

OBJECTIVE

The study was conducted to describe ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation in the treatment of intra-abdominal aggressive fibromatosis in seven patients who had failed surgery.

METHODS

We retrospectively investigated seven patients with pathologically proven intra-abdominal aggressive fibromatosis and surgical failure, who were treated with USgHIFU between June 2013 and February 2015. The main causes for surgical failure were a large tumour size or adjacent tissue invasion by the tumour. All of the patients were treated with palliative intent, to reduce symptoms of the diseases. The medical records were reviewed during the follow-up period, and the patients were asked to compare the symptoms of their disease as improved, unchanged or worsened, based on their levels before treatment. In addition, contrast-enhanced MRI was conducted to follow the size of the tumours before and after therapy.

RESULTS

The procedure was successfully accomplished in all of the patients without severe side effects. The median diameter of the tumours was 10.3 cm (range, 7.6-13.6 cm) and the mean ablation rate (the percentage rate of the non-perfused volume compared with the tumour volume on enhanced MRI after treatment) was 92.5 ± 3.7% (range, 86.5-96.8%). One patient underwent two treatments for a large tumour size, and other patients received single-visit therapy. All of the patient clinical symptoms remitted significantly after 6 months. The regression rates of the tumours were 34.8 ± 8.2% (range, 22.4-46.1%) and 58.2 ± 12.7% (range, 43.8-70.3%), respectively, at 6 and 12 months after treatment.

CONCLUSION

USgHIFU ablation could be an effective alternative minimally invasive therapy for the achievement of local control of intra-abdominal aggressive fibromatosis.

ADVANCES IN KNOWLEDGE

The conclusions indicate that USgHIFU ablation could be a promising alternative treatment for the achievement of local control of intra-abdominal aggressive fibromatosis.

The medico-legal observation of an aggressive urogenital fibromatosis with isolated development not related to any traumatic event

Desmoid tumor is a fibroproliferative neoplasm with an intermediate malignancy and it can be localized in every bodily district: some locations are considered exceptional, like the urogenital localization. The Author point out a rare case of giant idiopathic scrotal fibromatosis that was found during an autopsy. A widower, that lived alone in poor hygienic conditions, was found dead in his house. The Judicial Authority ordered the autopsy, that was performed two days later at the Medico-Legal Section of Milan University. External examinations revealed only the considerable dimension of the scrotum (cm 24 × 41). The cause of death was fixed in a cardiac tamponade due to a natural heart laceration localized in correspondence of a transmural infarction. The toxicological exam resulted negative, while the histopathological and immunohistochemical analysis qualify the scrotal mass as a desmoids tumor. Due to the absence of predisposing conditions and of fibroproliferative infiltration in bladder and retroperitoneal space, the neoplasm was configured as an idiopathic desmoid tumor. The presented case gives the reason for the discussion concerning medico-legal aspects that are typical of rare neoplasms.

Fibromatosis of the Sigmoid Colon With CTNNB1 (β-Catenin) Gene Mutation, Arising at the Site of Ileocolic Anastomosis for Resection of Gastrointestinal Stromal Tumor

We describe a case of intra-abdominal fibromatosis, which occurred in a 44-year-old woman who had a previous history of gastrointestinal stromal tumor (GIST) of the sigmoid mesocolon, which was treated with imatinib and resection. A mass was detected at the site of ileocolic anastomosis of the previous small bowel resection and sigmoid colectomy, nearly 3 years later. Clinically, this was suspected to represent recurrent GIST and was excised, but histology and mutational analysis showed desmoid-type fibromatosis with a mutation in codon 41 of exon 3 of the CTNNB1 (β-catenin) gene. The occurrence of fibromatosis at the site of excision of GIST is very rare, but its recognition is important as the treatment of the two neoplasms differs significantly. As imaging cannot reliably distinguish between these 2 entities, histological diagnosis is crucial for correct clinical management.

CTNNB1 (β-Catenin)-altered Neoplasia: A Review Focusing on Soft Tissue Neoplasms and Parenchymal Lesions of Uncertain Histogenesis

β-catenin (CTNNB1) is a key regulatory molecule of the Wnt signaling pathway, which is important for tissue homeostasis and regulation of cell proliferation, differentiation, and function. Abnormal stabilization and nuclear accumulation of β-catenin as a consequence of missense mutations or alternative molecular mechanisms occurs at a high frequency in a variety of epithelial cancers. In mesenchymal neoplasia, the role of β-catenin has been traditionally considered limited to desmoid-type fibromatosis. However, the spectrum of β-catenin-driven (β-catenin-altered) neoplasia of mesenchymal origin has been steadily widening to include, in addition to desmoid tumors, a variety of benign and intermediate-biology neoplasms of soft tissue (intranodal palisaded myofibroblastoma), head and neck (juvenile nasopharyngeal angiofibroma and sinonasal hemangiopericytoma/glomangiopericytoma), and ovarian (microcystic stromal tumor) origin. In addition, several old and newly reported distinctive site-specific β-catenin-driven parenchymal neoplasms of uncertain histogenesis have been well characterized in recent studies, including solid-pseudopapillary neoplasm of the pancreas and its recently described ovarian counterpart, sclerosing hemangioma of lung and calcifying nested stromal-epithelial tumor of the liver. This review addresses the most relevant pathobiological and differential diagnostic aspects of β-catenin-altered neoplasms with emphasis on site-specific histologic and biological variations. In addition, the morphologic overlap and analogy as well as distinctness between these uncommon tumors will be presented and discussed. Furthermore, a note is made on association of some of these lesions with hereditary tumor syndromes, in particular with the familial adenomatous polyposis coli.

High-grade soft tissue sarcoma arising in a desmoid tumor: case report and review of the literature

Desmoid tumors are rare benign monoclonal fibroblastic tumors. Their aggressiveness is local with no potential for metastasis or dedifferentiation. Here we report on a 61-year-old patient who presented a locally advanced breast desmoid tumor diagnosed 20 years after post-operative radiotherapy for breast carcinoma. After 2 years of medical treatment, a high-grade undifferentiated pleomorphic soft tissue sarcoma arose within the desmoid tumor. Despite extensive surgery removing both tumors, the patient showed locoregional relapse by the sarcoma, followed by multimetastatic progression, then death 25 months after the surgery. The arising of a soft tissue sarcoma in a desmoid tumor is an exceptional event since our case is the fourth one reported so far in literature. It reinforces the need for timely and accurate diagnosis when a new mass develops in the region of a preexisting desmoid tumor, and more generally when a desmoid tumor modifies its clinical or radiological aspect.

Desmoid-type fibromatosis

Desmoid-type fibromatosis is a rare, locally infiltrative, mesenchymal neoplasm that is associated with high rates of local recurrence but lacks the potential to metastasise. The disease affects younger individuals, with a peak age of 30 years, and is the most common cause of an anterior abdominal wall mass in young women of childbearing age. It may, however, involve nearly every body part, including the extremities, head and neck, trunk, and abdominal cavity; as such, desmoid-type fibromatosis may present to a range of general and subspecialty radiologists. These rare tumours have a widely variable clinical presentation and unpredictable natural history, hence input from a soft-tissue tumour centre is recommended, although much of the imaging may be performed at the patient's local hospital. The consensus for treatment has changed over the past decade, with most centres moving away from primary radical surgery towards a front-line 'watch-and-wait' policy. Therefore, imaging has an increasingly important role to play in both the diagnosis and follow-up of these patients. This review will discuss the typical imaging characteristics of these lesions and suggest diagnostic and follow-up magnetic resonance imaging protocols, with details of suitable sequences and scanning intervals.

[Intra-abdominal soft tissue tumors. What needs to be known to reach the diagnosis with the help of immunohistochemistry, FISH and molecular biology]

Connective tissue tumors located inside the abdomen are a rare heterogeneous group of tumors, except for gastro-intestinal stromal tumors. They may be benign, malignant, or intermediate in terms of biologic potential. Pathologists have to remember the list of all the lesions possibly involved, with their immunohistochemical characteristics, and to know which molecular analyses are needed, with which expected results, and by which team they can be performed. The main tumor types are discussed with diagnostic tools and treatment consequences.