Desmoid tumors, also referred to as aggressive fibromatosis, represent an uncommon form of fibroblastic proliferation. These neoplasms may arise within any musculoaponeurotic structure throughout the body. They are classified as benign due to several distinctive features: histologically, they exhibit regular mitotic activity and are devoid of metastatic potential. Computed tomography (CT) remains the definitive modality for precise diagnosis, and surgical excision is strongly advised. This account details the manifestation of a desmoid tumor located in the anterior abdominal wall of a 31-year-old female patient who notably lacks any prior surgical interventions. The surgical intervention entailed the excision of the neoplasm and subsequent reconstruction of the abdominal wall utilizing a polypropylene mesh. Postoperatively, the patient was released from the medical facility after a period of three days, having experienced no post-surgical complications. This was followed by a six-month interval free of any adverse events.

BACKGROUND: We have recently described circumferential nerve involvement of neuromuscular choristoma associated with desmoid-type fibromatosis (NMC-DTF) in cases involving the sciatic nerve, supporting a nerve-derived mechanism for the DTF. We wondered whether a similar growth pattern occurs in cases involving the brachial plexus (BP).
METHODS: We reviewed all available magnetic resonance (MR) imaging in patients diagnosed at our institution with NMC or NMC-DTF of the BP. We also performed a literature search of patients with NMC or NMC-DTF of the BP.
RESULTS: In our clinical records, four patients with NMC of the BP were identified, and three developed NMC-DTF. All three patients had MR imaging evidence of circumferential encasement of the BP. In the literature, we identified 15 cases of NMC of the BP, of which 12 had identified NMC-DTF. Four published cases included MR images, and only two were of sufficient quality for review. The single provided image in both cases demonstrated a similar pattern of circumferential encasement of the BP by the NMC-DTF. One additional case report was published without MR images but described circumferential involvement in the surgical findings. One unpublished case of NMC-DTF of the BP from an international radiology meeting also had this circumferential pattern pattern on MRI.
CONCLUSIONS: The MRI findings of circumferential nerve involvement in patients with NMC-DTF of the BP are similar to our previously reported data in patients with NMC-DTF of the sciatic nerve, providing further imaging-based support of a nerve-driven mechanism. Clinical implications are presented based on the proposed pathogenetic mechanism.

Diagnosis of desmoid-type fibromatosis (DF) may be challenging on biopsy due to morphologic overlap with reactive fibrosis (scar) and other uniform spindle cell neoplasms. Evaluation of nuclear β-catenin, a surrogate of Wnt pathway activation, is often difficult in DF due to weak nuclear expression and high background membranous/cytoplasmic staining. Lymphoid enhancer-factor 1 (LEF1) is a recently characterized effector partner of β-catenin which activates the transcription of target genes. We investigated the performance of LEF1 and β-catenin immunohistochemistry in a retrospective series of 156 soft tissue tumors, including 35 DF, 3 superficial fibromatosis, and 121 histologic mimics (19 soft tissue perineurioma, 8 colorectal perineurioma, 4 intraneural perineurioma, 26 scars, 23 nodular fasciitis, 6 low-grade fibromyxoid sarcomas, 6 angioleiomyomas, 5 neurofibromas, 5 dermatofibrosarcoma protuberans, 3 low-grade myofibroblastic sarcomas, 3 synovial sarcomas, 3 inflammatory myofibroblastic tumors, 2 schwannomas, and 1 each of Gardner-associated fibroma, radiation-associated spindle cell sarcoma, sclerotic fibroma, dermatofibroma, and glomus tumor). LEF1 expression was not only seen in 33/35 (94%) of DF but also observed in 19/23 (82%) nodular fasciitis, 7/19 (37%) soft tissue perineurioma, 2/3 (66%) synovial sarcoma, and 6/26 (23%) scar, as well as in 1 radiation-associated spindle cell sarcoma. The sensitivity and specificity of LEF1 IHC for diagnosis of DF were 94% and 70%, respectively. By comparison, β-catenin offered similar sensitivity, 94%, but 88% specificity. Positivity for LEF1 and β-catenin in combination showed sensitivity of 89%, lower than the sensitivity of β-catenin alone (94%); however, the combination of both LEF1 and β-catenin improved specificity (96%) compared to the specificity of β-catenin alone (88%). Although LEF1 has imperfect specificity in isolation, this stain has diagnostic utility when used in combination with β-catenin.

UNASSIGNED: Because size-based imaging criteria poorly capture biologic response in desmoid-type fibromatosis (DF), changes in MRI T2 signal intensity are frequently used as a response surrogate, but remain qualitative. We hypothesized that absolute quantification of DF T2 relaxation time derived from parametric T2 maps would be a feasible and effective imaging biomarker of disease activity.
UNASSIGNED: This IRB-approved retrospective study included 11 patients with DF, managed by observation or systemic therapy, assessed by 3T MRI. Tumor maximum diameter, volume, and T2-weighted signal intensity were derived from manual tumor segmentations. Tumor:muscle T2 signal ratios were recorded. Two readers measured tumor T2 relaxation times using a commercial T2 scanning sequence, manual ROI delineation and commercial calculation software enabling estimation of reader reliability. Objective response rates based on RECIST1.1 and best responses were compared between size-based and signal-based parameters.
UNASSIGNED: Median patient age was 52.6 years; 8 subjects were female (73%). Nine patients with longitudinal assessments were followed for an average of 314 days. Median baseline tumor diameter was 7.2 cm (range 4.4 - 18.2 cm). Median baseline T2 was 65.1 ms (range 40.4 - 94.8 ms, n=11); median at last follow-up was 44.3 ms (-32% from baseline; range 29.3 - 94.7 ms, n=9). T2 relaxation times correlated with tumor:muscle T2 signal ratios, Spearman p=0.78 (p<0.001). T2 mapping showed high inter-reader reliability, ICC=0.84. The best response as a percentage change in T2 values was statistically significant (mean -17.9%, p=0.05, paired t-test) while change in diameter was not (mean -8.9%, p=0.12).
UNASSIGNED: Analysis of T2 relaxation time maps of DF may offer a feasible quantitative biomarker for assessing the extent of response to treatment. This approach may have high inter-reader reliability.

BACKGROUND: Desmoid tumours (DTs) or deep fibromatosis are benign soft-tissue tumours, sometimes locally aggressive, requiring intervention on some cases. Surgery has been the gold standard, but new less invasive techniques such as percutaneous cryoablation have proved their effectiveness, reducing health resources and complications. The study aimed to compare the total cost of percutaneous cryoablation and conventional surgery for patients with extra-abdominal and/or abdominal wall DTs, candidates for local ablative treatment in Spain.
METHODS: A cost-analysis model was developed. An expert panel provided data about resource consumption for the percutaneous cryoablation technique and validated the epidemiology used for target population estimation. Unitary resources cost (€ 2022) derived from local cost databases. A retrospective analysis of 54 surgical cases in 3 Spanish hospitals was performed to estimate the cost of conventional surgery based on the cost of the Diagnosis-Related group (DRG) codes identified on this patient sample, weighted by each DRG proportion. The total cost for each alternative included intervention cost and complications cost, considering debridement required in 4.5% of cases with percutaneous cryoablation and minor surgery for surgical site infection in 18.0% for conventional surgery.
RESULTS: The total cost for percutaneous cryoablation (€ 5774.78/patient-year) was lower than the total cost for conventional surgery (€ 6780.98/patient-year), yielding cost savings up to € 80,002 in 1 year for the entire cohort of 80 patients with DTs eligible for intervention estimated in Spain. One-way sensitivity analyses confirmed the results\' robustness.
CONCLUSIONS: Percutaneous cryoablation versus conventional surgery would yield cost savings for the management of DT patients in Spain.
UNASSIGNED: This manuscript provides insight into the economic impact derived from the savings related to the use of percutaneous cryoablation for desmoid-type tumours from the perspective of the Spanish National Healthcare System, providing useful information for the health decision-making process.
CONCLUSIONS: • Desmoid tumours are locally aggressive and may require local therapy. • Percutaneous cryoablation procedure is less invasive than the conventional surgery. • Cost comparison shows savings associated to percutaneous cryoablation use.

UNASSIGNED: Desmoid-type fibromatosis (DF) is characterized by a rare monoclonal fibroblast proliferation that exhibits variable and unpredictable clinical presentation. DF can be classified into sporadic and hereditary types. Despite extensive research efforts, the exact etiology of DF remains elusive.
UNASSIGNED: A 31-year-old male patient presented to the hospital with a progressively growing mass in the right lower abdomen, accompanied by abdominal discomfort. Symptoms are discovered 1 week before admission. Enteroscopy revealed no evidence of colonic abnormalities, and blood tests did not indicate any abnormalities. Due to the indeterminate nature of the mass during surgery, a partial resection of the ileum and cecum was performed, followed by ileocolonic end-to-end anastomosis, with no postoperative complications. The final pathological diagnosis confirmed primary desmoid-type fibromatosis of the distal ileum (invasive fibromatosis). To effectively manage DF, we recommend a follow-up schedule for patients. This includes appointments every 3 months in the first year following surgery, followed by appointments every 6 months up to the fifth year, and then once a year thereafter. The follow-up examinations should include collection of the patient\'s medical history, physical examination, blood tests, ultrasounds, CT scans, and other relevant assessments. During the first year of the follow-up period, no further treatment was administered, and the patient remained disease-free.
UNASSIGNED: Desmoid-type fibromatosis (DF) originating from the small intestine is an extremely rare condition that exhibits local invasiveness and can be life-threatening. Despite its benign histology, DF has a high local recurrence rate and lacks metastatic potential. Diagnosis of DF remains challenging, especially in cases where surgical intervention is not feasible due to asymptomatic patients or partial organ impairment. In such cases, a \"watchful waiting\" approach is recommended as the initial treatment strategy. However, when preoperative diagnosis is difficult, surgery is typically considered the best option. Given the potential for local recurrence and the uncertain long-term prognosis, regular follow-up is necessary.

OBJECTIVE: Although the treatment of abdominal wall desmoid-type fibromatosis (DF) has evolved over the past decades, surgical treatment remains an important approach. Previously, surgeries for abdominal DF were mostly performed by laparotomy, which involves massive dissection and significant trauma. Here, we report our single-center experience of the laparoscopic management of abdominal wall DF in young female patients.
METHODS: The clinical data of nine patients diagnosed with abdominal wall DF during January 2020-April 2022 at the Qilu Hospital of Shandong University were retrospectively analyzed. All patients underwent laparoscopic resection of abdominal wall DF and immediate abdominal wall reconstruction (AWR) with mesh augmentation via the intraperitoneal onlay mesh (IPOM) technique.
RESULTS: Laparoscopic DF resection and AWR were successfully performed in all patients. The mean operation time was 175.56 ± 46.20 min. The width of abdominal wall defect was 8.61 ± 3.30 cm. Full- and partial-thickness myofascial closure and reapproximation were performed in five, two, and two patients, respectively. The average mesh size was 253.33 ± 71.01 cm2. The total and postoperative lengths of hospital stay were 11.00 ± 3.46 and 4.89 ± 2.03 days, respectively. Tumor recurred in one patient after 20 months of the resection. Nonetheless, death, herniation, or bulging were not observed in any patient during a mean follow-up of 16.11 ± 8.43 months.
CONCLUSIONS: Laparoscopic resection of abdominal wall DF and immediate AWR with IPOM mesh reinforcement is safe and reliable for young female patients. Management of such patients should be decided according to the biological behavior, size, and location of tumors.

OBJECTIVE: Neuromuscular choristoma (NMC) is a rare developmental malformation of peripheral nerve that is frequently associated with the development of a desmoid-type fibromatosis (DTF). Both NMC and NMC-DTF typically contain pathogenic CTNNB1 mutations and NMC-DTF develop only within the NMC-affected nerve territory. The authors aimed to determine if there is a nerve-driven mechanism involved in the formation of NMC-DTF from the underlying NMC-affected nerve.
METHODS: Retrospective review was performed for patients evaluated in the authors\' institution with a diagnosis of NMC-DTF in the sciatic nerve (or lumbosacral plexus). MRI and FDG PET/CT studies were reviewed to determine the specific relationship and configuration of NMC and DTF lesions along the sciatic nerve.
RESULTS: Ten patients were identified with sciatic nerve NMC and NMC-DTF involving the lumbosacral plexus, sciatic nerve, or sciatic nerve branches. All primary NMC-DTF lesions were located in the sciatic nerve territory. Eight cases of NMC-DTF demonstrated circumferential encasement of the sciatic nerve, and one abutted the sciatic nerve. One patient had a primary DTF remote from the sciatic nerve, but subsequently developed multifocal DTF within the NMC nerve territory, including 2 satellite DTFs that circumferentially encased the parent nerve. Five patients had a total of 8 satellite DTFs, 4 of which abutted the parent nerve and 3 that circumferentially involved the parent nerve.
CONCLUSIONS: Based on clinical and radiological data, a novel mechanism of NMC-DTF development from soft tissues innervated by NMC-affected nerve segments is proposed, reflecting their shared molecular genetic alteration. The authors believe the DTF develops outward from the NMC in a radial fashion or it arises in the NMC and wraps around it as it grows. In either scenario, NMC-DTF develops directly from the nerve, likely arising from (myo)fibroblasts within the stromal microenvironment of the NMC and grows outward into the surrounding soft tissues. Clinical implications for patient diagnosis and treatment are presented based on the proposed pathogenetic mechanism.

Desmoid-type fibromatosis (DF) is a rare subtype of soft tissue sarcomas that most commonly occurs in the anterior abdominal wall. When occurring in the retroperitoneum, DF is usually part of familial syndromes while only rarely sporadic. This makes it imperative to report any instance of experience with DF and the oncological outcomes of the different approaches to management. We report two cases of sporadic and severe DF occurring in the retroperitoneum at our institution.
UNASSIGNED: The first case is a male that presented with urinary obstruction symptoms and underwent surgical resection of the tumor that extended into the left kidney. The second case is a female with a history of recurrent desmoid tumors of the thigh and was incidentally diagnosed with retroperitoneal DF on imaging. She underwent tumor resection and radiotherapy; however, the tumor recurred with urinary obstruction symptoms that required another surgical resection. Histopathological characteristics and radiological imaging of both cases are described below.
UNASSIGNED: Desmoid tumors often recur, thus significantly influencing the quality of life which is reflected in one of our cases. Surgery remains a mainstay treatment, and both cases presented in this report required surgical resection of the tumors as symptomatic and curative measures.
UNASSIGNED: Retroperitoneal DF is a rare entity, and our cases add to the scarce literature available on the topic, which may well contribute to the formulation of practice-changing recommendations and guidelines focused on this rare variant of DF.

Sorafenib is currently one of the recommended treatments for symptomatic patients with desmoid-type fibromatosis (DTF). In this study, we aim to assess the clinical efficacy and tolerability of sorafenib in DTF patients.
Patients aged>18 years with a histological diagnosis of DTF and who have received sorafenib were enroled in this prospective observational study. Demographic data, clinical profile, the initial dose of sorafenib, treatment-related toxicities, dose modifications, and responses were recorded. The primary objective was to assess the objective response rate (ORR). The secondary objectives were to evaluate progression-free survival (PFS), tolerability, and adverse effects of sorafenib. Response assessment was based on response evaluation criteria in solid tumours 1.1 criteria. Adverse effects were graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0 criteria. Time to event was calculated by Kaplan-Meier analysis, and survival was compared by log-rank test. Univariate and multivariable cox regression analysis were used to find independent predictors of relapse.
A total of 104 patients were enroled in the study. The median age of the study population was 32 (range, 18-81) years, and 66.35% of patients were females. On response assessment, ORR was 46.1% and stable disease was observed in 31.7% patients. ORR was higher in the appendicular site (51.7%) compared to the abdominal site (27.2%). PFS at 1 and 2 years was 86.6% (79.6-92.7%) and 73.7% (62.4-82.8%), respectively. Two-thirds (66.6%) of patients had already received some form of treatment. At the time of analysis, 70 (67.3%) patients were continuing sorafenib. Only 4.8% stopped sorafenib due to progression, 10.5% due to intolerable adverse effects, and 17.3% due to other reasons. The common treatment-related toxicities were hand-foot skin reaction (HFSR) (89.4%), fatigue (79.8%), alopecia (70.1%), and diarrhoea (48.0%). In the patients with a starting dose of ≥400 mg (48.0% of patients), discontinuation was necessitated in 12% of patients, and further dose reduction was required in 58%, while only about 13% required dose reduction or discontinuation at a starting dose of 200 mg (51.9% of patients). Responses were not compromised due to lower starting doses.
Sorafenib has good activity in DTF, but it is associated with significant toxicity. The adverse effect profile is distinct in Indian patients with higher HFSR and alopecia. Due to the high rate of dose reduction/discontinuation with a starting dose of 400 mg, a starting dose of 200 mg may be recommended in Indian patients.