To assess the efficacy and safety of ultrasound (US)-guided high-intensity focused ultrasound (HIFU) ablation for treatment of unresectable and recurrent intra-abdominal desmoid tumors. From June 2014 to March 2020, 15 patients with consecutive unresectable and recurrent diseases that pathologically proven to be intra-abdominal desmoid tumors had undergone the treatment of US-guided HIFU ablation. All patients underwent contrast-enhanced magnetic resonance imaging before and after HIFU treatment. Nonperfused volume ratio was used to evaluate the effect of HIFU therapy. Intraprocedural and postprocedural adverse effects and complications are recorded to assess the safety of the therapy. Outcome of HIFU ablation has been investigated through serial contrast-enhanced imaging examinations during follow up. Out of 15 patients 14 of them have successfully completed the whole therapy, 1 patient is ineffective and gives up further treatment. The mean nonperfused volume ratio is 71.1% (95% confidence interval, 3% to 88.2%). During a mean follow up of 29 months (range from 8 to 61 months), the mean tumor volume was reduced by 59% (95% confidence interval, +49% to -100%). No tumor spreads along the treated area in all patients except one. Complications have occurred in 5 patients (33.3%), including bowel rupture (1 case), intra-abdominal abscess (1 case), slight injury to the femoral nerve (1 case), and bone injury (2 cases), the bowel rupture patient underwent surgery; the others have been cured during the follow up. US-guided HIFU ablation is an effective treatment modality for patients suffered from unresectable and recurrent intra-abdominal desmoid tumors.

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.
OBJECTIVE: 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.
CONCLUSIONS: 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.

Desmoid tumors can be safely managed with watchful waiting, including either observation alone or tamoxifen/NSAIDs. Surgery at first presentation can be associated with significant treatment burden.
Immediate surgery was historically recommended for desmoid tumors. Recently, watchful waiting, (tamoxifen/NSAIDs or observation alone), has been advocated.
All diagnoses of desmoid tumor within the Alberta Cancer Registry from August 2004 to September 2015 were identified. Patients with FAP were excluded. Demographics, tumor characteristics and treatment and outcome data were collected. Outcomes were compared between immediate surgery and watchful waiting. The effect of abdominal wall site on progression and recurrence and the effect of microscopic margin on recurrence were assessed with Fisher\'s exact test.
We identified 111 non-FAP patients. Median follow-up was 35 months from diagnosis. 74% were female. Mean age was 42. Fifty (45%) underwent watchful waiting, of whom 21(42%) progressed, with median PFS of 10 months. Fifty-three (48%) underwent resection at presentation, of whom 8 (15%) recurred, with median disease-free survival of 22 months. Abdominal wall lesions were equally represented in both groups, and equally likely to progress on watchful waiting (50% vs 39%, p = 0.53), but there was a trend toward decreased recurrence after surgery. (5% vs 23%, p = 0.08). Microscopic margin had no effect on recurrence (14% of margin negative vs 20% of margin positive, p = 1.0).
Watchful waiting was successful in 58% of patients, and a further 28% only required one aggressive treatment thereafter, for a total of 86%. Surgery had a favorable recurrence rate (15%), but some recurrences were associated with significant treatment burden. Treatment should be tailored to individual patients in a multidisciplinary setting. A trial of observation appears warranted in most patients. Recurrence rate was not affected by positive margins.

BACKGROUND: Aggressive fibromatosis (AF) is a locally infiltrating soft-tissue tumor. In a population-based study in the Netherlands, we evaluated time trends for the incidence and treatment of AF.
METHODS: In PALGA: Dutch Pathology Registry, all patients diagnosed between 1993 and 2013 as having extra-abdominal or abdominal wall aggressive fibromatosis were identified and available pathology data of the patients were evaluated. Epidemiological and treatment-related factors were analyzed with χ (2)and regression analysis.
RESULTS: During the study period, 1134 patients were identified. The incidence increased from 2.10 to 5.36 per million people per year. Median age at the time of diagnosis increased annually by B 0.285 (P = 0.001). Female gender prevailed and increased over time [annual odds ratio (OR) 1.022; P = 0.058]. All anatomic localizations, but in particular truncal tumors, became more frequent. During the study period diagnostic histological biopsies were performed more often (annual OR 1.096; P < 0.001). The proportion of patients who underwent surgical treatment decreased (annual OR 0.928; P < 0.001). When resection was preceded by biopsy, 49.8 % of the patients had R0-resection versus 30.7 % in patients without biopsy (P < 0.001).
CONCLUSIONS: In this population-based study, an increasing incidence of extra-abdominal and abdominal-wall aggressive fibromatosis was observed. The workup of patients improved and a trend towards a nonsurgical treatment policy was observed.

We hypothesized that patterns of CTNNB1 (β-catenin) mutations would affect the outcome of conservative therapy in patients with desmoid tumors. This study aimed to determine the significance of CTNNB1 (β-catenin) mutations in predicting the treatment outcome in patients with desmoid tumors treated with meloxicam, a cyclooxygenase-2 (COX-2) selective inhibitor. Between 2003 and 2012, consecutive thirty-three patients with extra-peritoneal sporadic desmoid tumors were prospectively treated with meloxicam as the initial systemic medical therapy. The efficacy of meloxicam was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST). DNA was isolated from frozen tissue or formalin-fixed materials. CTNNB1 mutation analysis was performed by direct sequencing. Positivity of nuclear β-catenin staining by immunohistochemistry was compared with the status of CTNNB1 mutations. The correlation between the efficacy of meloxicam treatment and status of CTNNB1 mutations was analyzed. Of the 33 patients with meloxicam treatment, one showed complete remission (CR), 7 partial remission (PR), 12 stable disease (SD), and 13 progressive disease (PD). The following 3 point mutations were identified in 21 of the 33 cases (64%): T41A (16 cases), S45F (4 cases) and S45P (one case). The nuclear expression of β-catenin correlated significantly with CTNNB1 mutation status (p = 0.035); all four cases with S45F mutation exhibited strong nuclear expression of β-catenin. S45F mutation was significantly associated with a poor response (all cases; PD) (p = 0.017), whereas the other mutations had no impact on efficacy. The CTNNB1 mutation status was of significant prognostic value for meloxicam treatment in patients with sporadic desmoid tumors.

OBJECTIVE: To determine the tolerability, effectiveness and outcomes of percutaneous image-guided cryoablation on inoperable extra-abdominal desmoid tumors.
METHODS: Between 2011 and 2012, 13 patients (mean age 39.3 years, range 15-74) with inoperable extra-abdominal desmoid tumors were consecutively treated with cryoablation (17 tumors treated in 17 procedures), including two patients with Gardner syndrome and nine recurrences after surgery. Disease-free survival (DFS) and local control based on RECIST criteria were calculated on prospective clinical and imaging follow-up until 2013.
RESULTS: Cryoablation was performed under ultrasound (n = 8), computed tomography (n = 1), or combined (n = 8) guidance, and under general (n = 15) or local (n = 2) anesthesia. A major complication was observed in one session (5.8%). Mean follow-up was 11.3 months (6-27 months). Among all the patients treated, eight patients (47%) presented residual tumors on the first magnetic resonance follow-up, which were asymptomatic. The DFS rate was stable at 82.3% (95% confidence interval 0.55-0.94) at 6, 12, and 24 months. The local tumor progression rate was 0% at 6, 12, and 24 months. Two patients (12%) presented an in situ recurrence.
CONCLUSIONS: Despite high rates of partial ablation, percutaneous image-guided cryoablation appears to be safe and effective for local control for patients with inoperable extra-abdominal desmoid tumors.

Desmoid tumors are benign monoclonal fibroblastic or myofibroblastic neoplasms, characterized by local invasiveness and high rates of recurrence. Desmoid tumors must be distinguished from benign fibroblastic and myofibroblastic lesions, as well as from low-grade sarcoma, which can appear histologically similar to desmoid tumors. This differential diagnosis can be very difficult, especially when diagnosis is based on a core needle biopsy. On the molecular level, most sporadic desmoid tumors are associated with mutations of the β-catenin gene (CTNNB1). A minority of desmoid tumors are associated with Gardner syndrome and mutations of the familial adenomatous polyposis gene. We identified the common CTNNB1 mutations associated with sporadic desmoid tumors by direct sequencing: in (i) 260 cases of typical desmoid tumors; and (ii) in 191 cases of spindle cell lesions, which can morphologically \'mimic\' desmoid tumors. Formalin-fixed paraffin-embedded tissues were obtained via core needle biopsy (n=150) or open biopsy/surgical excision (n=301). Only 16 cases (4%) were not analyzable (Bouin\'s fixed tissue). CTNNB1 mutations were observed in 223 of 254 (88%) of sporadic desmoid tumors. No CTNNB1 mutations were detected in all other lesions (n=175) studied. CTNNB1 sequencing can be easily and reliably done using tissues obtained via core needle biopsy. Detection of CTNNB1 mutations in formalin-fixed paraffin-embedded tissues among spindle cell lesions is proposed as a specific diagnostic tool for the diagnosis of desmoid tumors. This result has significant implications for patient care and management.

BACKGROUND: Ability to identify patients with familial adenomatous polyposis who have a high risk of developing desmoid tumors may affect decisions in clinical practice.
OBJECTIVE: Our aim was to assess several risk factors for desmoid tumor development in an international cohort of patients with familial adenomatous polyposis and to evaluate the clinical relevance of risk factors.
METHODS: This was a retrospective cohort study.
METHODS: Polyposis registries in The Netherlands, France, Denmark, Finland, and Italy provided information on familial adenomatous polyposis patients with desmoid tumors.
METHODS: We used univariate and multivariable analyses of data from registries in The Netherlands, France, Denmark, and Finland to test whether gender, APC mutation site, previous colorectal surgery, colorectal cancer, and family history for desmoid tumors contribute to risk of developing desmoid tumors at any location, or specifically at an intra-abdominal location. The effect of family history was tested with a generalized linear mixed model.
RESULTS: : Of 2260 patients with familial adenomatous polyposis from 912 families in The Netherlands, France, Denmark, and Finland, 220 patients (10%) had desmoid tumors (101 men). In 387 patients with desmoid tumors (including 167 patients from the Italian registry), the median age at diagnosis of the first desmoid tumor was 31 years (range, 4 months-74 years). Desmoid locations were intra-abdominal (53%), abdominal wall (24%), extremities (9%), and unknown sites or combinations of sites (14%). Multivariable analysis of risk factors for desmoids at any location showed surgery (OR, 2.58; P = .0004), an APC mutation 3\' of codon 1444 (OR, 3.0; P < .0001), and a positive family history (P < .0001) to be independently associated with desmoid development. When only intra-abdominal location was analyzed, APC mutation site was not associated with desmoid development.
CONCLUSIONS: Selection bias may have occurred.
CONCLUSIONS: A positive family history for desmoid tumors, abdominal surgery, and APC mutation site are significant risk factors for development of desmoid tumors. The results may have implications for determining the optimal management of FAP patients and guide future studies.

Mesenteric fibromatosis (MF) and gastrointestinal stromal tumors (GISTs) are distinct lesions, but they often are confused with each other. Correct identification is essential because of their vastly different therapeutic and prognostic connotations. We reviewed 25 cases of MF with involvement of the wall of the gastrointestinal tract and found that GIST was the most common misdiagnosis (13 [52%]). MF was characterized by a spatially homogeneous proliferation of wavy spindle cells without atypia, associated with collagen deposition (often of the keloidal type), and an infiltrative border. Most cases displayed prominent muscular arteries and dilated, thin-walled veins. The mitotic count was relatively low, and no atypical mitotic figures were identified. These features are sufficiently characteristic of MF to permit distinction from GIST on the basis of routinely stained sections in the large majority of the cases, but immunohistochemical analysis provides a supporting role in the few equivocal cases.

Small bowel transplantation is coming of age. Although still considered an experimental procedure, much has been accomplished to bring this surgery closer to routine. This article describes the current status of small bowel transplantation and discusses the first successful small bowel transplantation between identical twins. The issues of workup, surgery, postoperative follow-up, common complications, and the history and future of small bowel transplantation are addressed.