Desmoid Fibromatosis Research Articles

S4810 Obstructive Conundrum: Desmoid Fibromatosis as a Rare Cause of Small Bowel Obstruction

S2504 Infiltrative Desmoid Fibromatosis of the Pancreatic Tail Diagnosed by Endoscopic Ultrasound-Guided Fine-Needle Aspiration

The casuistry of benign triton tumor/neuromuscular choristoma (NMC) in the world medical literature has no more than 40–50 observations. There are no descriptions of a such disease in Russian sources. Here is our own case. A 6-year-old boy was diagnosed with a benign tumor of the right sciatic nerve. Sciatic neurolysis and removal of the neoplasm with a size of 8 × 3 × 3 cm were performed. Histological and immunohistochemical investigation revealed a tumor built of bundles of striated muscles and nerve fibers intertwined in the collagen matrix. Conclusion: benign triton tumor (NMC).NMC is an extremely rare neoplasm associated with large nerves and occurs more often in childhood. Pain syndrome/neuropathy is usually clinically registered. Although a mature triton tumor is considered benign, it often has recurrences and desmoid fibromatosis (mainly postoperative): it is assumed that trauma stimulates fibroblasts/myofibroblasts with a mutation of the CTNNB1 gene. For this reason, noncontact diagnosis is recommended for patients with classic clinical and radiological signs of NMC. To develop an optimal approach to the treatment of this tumor and to assess the long-term prognosis of the disease, it is necessary to accumulate a sufficient number of observations.

Presented are three casuistics of seemingly identical breast lesions which even by adopting advanced laboratory techniques may represent diagnostic challenge. Microscopic features of some bland spindle cell lesions of different histogenesis (epithelial or mesenchymal) are misleading and a potential source of unaware errors, which might affect optimal therapeutic strategy. In the setting of three diverse entities (low-grade spindle cell metaplastic carcinoma, desmoid fibromatosis and phyllodes tumor) is documented both demanding diagnostic algorithm and revealing molecular landscape on one side as well as evolving predictive/prognostic parameters on the other one. Close interdisciplinary cooperation is inevitable for accurate interpretation/understanding of revealed diagnostic facts which is required for adjustment of competent rational and individualized therapy.

Desmoid fibromatosis (DF) is a rare locally aggressive soft tissue tumour that is characterized as benign as it cannot metastasize. It was managed until recently like sarcomas, that is, with radical surgical resection combined or not with radiotherapy. However, this approach was associated with a high rate of recurrence and significant morbidity. The management of this disease has progressively changed to a more conservative approach given the fact that DF may spontaneously stop to grow or even shrink in more than half of the cases. Should treatment be required, recent guidelines recommend choosing between systemic therapies, which include principally chemotherapy and tyrosine kinase inhibitors, and local treatments. And this is where the interventional radiologist may have an important role in treating the disease. Various ablation modalities have been reported in the literature to treat DF, notably high-intensity focused ultrasound and cryoablation. Results are promising and cryoablation is now mentioned in recent guidelines. The interventional radiologist should nevertheless apprehend the disease in its globality to understand the place of percutaneous treatments among the other therapeutic options. The goal of this review is therefore to present and discuss the role of interventional radiology in the management of DF.

Objective: To investigate the clinicopathological and genetic characteristics of neuromuscular choristoma-associated desmoid type fibromatosis (NMC-DF). Methods: The clinical morphological and immunohistochemical features of 7 NMC-DF cases diagnosed from January 2013 to January 2023 in Beijing Jishuitan Hospital were retrospectively analyzed. A series of neuromuscular choristoma and neuromuscular choristoma-associated desmoid type fibromatosis were evaluated for CTNNB1 mutations, and hotspot mutations for CTNNB1 were tested in 4 NMC-DF cases using Sanger sequencing. Results: The tumors were collected from 3 females and 4 males, aged 1 to 22 years (mean 7.1 years), involving the sciatic nerve (n=4), brachial plexus (n=2) or multiple nerves (n=1). The course of the disease spanned from 3 months to 10 years. Two cases were recurrent tumors. All the 7 NMC cases showed endoneurial intercalation of mature skeletal muscle fibers among the peripheral nerve fascicles, and the histologic features of the NMC-DF were strikingly similar to the conventional desmoid-type fibromatosis. By immunohistochemistry, all NMC and NMC-DF cases showed aberrant nuclear staining of β-catenin (7/7), the muscle cells in NMC were intensely immunoreactive for desmin, and the admixed nerve fibers were highlighted by NF and S-100 (7/7). Four NMC and NMC-DF had CTNNB1 mutations, 3 c.121A>G (p.T41A) and 1 c.134C>T (p.S45F). Follow-up of the 7 cases, ranging from 22 to 78 months, showed tumor recurrence in 2 patients at 3 and 8 months respectively after the first surgical resection, of which 1 patient underwent above-knee amputation. No recurrence occurred in other cases with tumor excision and neurological reconstruction surgery. There was no metastasis occurred in the 7 cases. Conclusions: NMC is a rare congenital lesion with differentiated mature skeletal muscle tissue found in peripheral nerve fascicles, and approximately 80% of patients with NMC develop a soft tissue fibromatosis. CTNNB1 mutation in the Wnt signaling pathway may be involved in the pathogenesis of NMC and NMC-DF, and S45F mutations seems to have a higher risk of disease progression.

Background. The main method of treatment of desmoid fibromatosis is surgical, especially in patients with symptomatic disease or in cases of progression during the Look and Stay period. Due to the rarity of the disease, different localization, unpredictability of the clinical course, the lack of generally accepted clear criteria for choosing a treatment method and/or a sequence of treatment methods, the determination of prognostic criteria for the course of the disease is of great scientific and practical interest. Aim. To study the immediate and long-term outcomes of surgical treatment in patients with retroperitoneal and abdominal desmoid fibromatosis. Materials and methods. The study analyzed the data of 121 patients with histologically verified retroperitoneal and abdominal desmoid fibromatosis who underwent surgical treatment at the Blokhin National Medical Research Center of Oncology from 1999 to 2022. Results. In 89% of cases, desmoid tumors are resectable; however, resections of adjacent organs are often required to remove the tumor mass completely. The frequency of combined interventions in the abdominal and retroperitoneal groups was 7.0 and 60.4%, respectively. Tumor cells along the edge of the incision are identified in 15.8% of patients, including 10% of patients with macroscopically detectable residual tumors. Surgical treatment of patients with desmoid tumors is associated with an acceptable complication rate and provides high rates of overall and relapse-free survival. Risk factors for disease-free survival of operated patients are retroperitoneal localization, multicentric tumor growth, and R2 category. Conclusion. The treatment of patients with retroperitoneal and abdominal desmoid tumors should be carried out in specialized clinics with sufficient experience in performing surgical interventions, including combined ones. The treatment approach in patients with desmoid tumors should be selected by a multidisciplinary team based on personalized oncological and functional prognoses in accordance with the prognostic risk groups.

Abstract BACKGROUND Familial adenomatous polyposis (FAP) is an autosomal-dominant dominant Familial Cancer Syndrome FCs Caused by Germline inactivation of adenomatous polyposis coli (APC) tumor suppressor gene, results in up-regulation of the WNT signaling pathway which increases the risk of colorectal cancer CRC, colon polyposis and extracolonic tumors like gastric and duodenal carcinomas WNT-activated Medulloblastoma MBL and Desmoid fibromatosis (DF) DF are locally aggressive soft tissue tumors with high local recurrence rates after Surgical excision role of adjuvant chemotherapy or Radiotherapy is still unclear. METHODS A 6-year-old boy product of non-consanguineous marriage with positive family HX brain tumor Diagnosed with Non-Metastatic Average Risk MBL WHO grade IV classic histology, he had craniotomy and Gross tumor resection followed by craniospinal irradiation at 23.4 Gy, plus a boost to posterior fossa/tumor bed up to 54 Gy, followed by 8 maintenance chemotherapy cycles as HIT-MED protocol Cisplatin/VCR/CCNU total. 3 years post end of therapy the pateint was in complete remission from MBL when routing MRI surveillance showed a new left paravertebral muscle lesion within the irradiation field from T1 to T4 levels which progressed gradually over a short follow-up time he had surgical resection of the tumor with Pathological diagnosis of Desmoid fibromatosis. after six months he had a second recurrence of the spinal tumor that needed a second surgical resection. Result: positive Genetic testing for Germline pathogenic mutation of APC gene exons 7 to 16 confirmed the diagnosis of autosomal familial adenomatous polyposis type 1(FAP1). Up to date, he is stable on endoscopic and MRI surveillance with radiological evidence of slow progression of the paraspinal tumor CONCLUSION Medulloblastomas associated with APC germline mutation have favorable outcomes that may need de-escalating therapeutic protocol with reduced intensity craniospinal irradiation aiming to reduce the incidence of secondary tumors after adjuvant treatment for MBL

e23516 Background: Intra-abdominal desmoid tumor (IADT) can mimic the recurrence/metastases of gastrointestinal stromal tumors (GISTs). However, it is difficult to radiologically differentiate IADT and recurrence/metastases of GISTs. This study aims to investigate the value of 18F fibroblast activation protein inhibitor ( [18F]FAPI-42) PET/CT in identifying intra-abdominal desmoid type fibromatosis mimicking recurrence/metastases of GISTs by comparing it to [18F]FDG PET/CT. Methods: This study retrospectively included a total of 24 patients (12 patients with IADT and 12 patients with recurrent/metastatic GISTs). The differences in [18F]FAPI-42 PET/CT parameters (SUVmax-FAPI and SUVTLR-FAPI ), [18F]FDG PET/CT parameters (SUVmax-FDG and SUVTLR-FDG), SUVfapi/SUVfdg ratio of IADT and GISTs were compared. The difference in PET/CT parameters (SUVmax, SUVTLR) of IADT between FDG PET/CT and FAPI PET/CT were compared. Immunohistochemical verification was performed on IADT lesions of all 12 patients and expression profiles of GEO datasets were analyzed to validate the FAP expression of IADT. Results: Both [18F]FAPI-42 PET/CT parameters, SUVmax-FAPI [8.8 (2.0, 16.0) vs 1.9 (1.0, 6.0), P< 0.001]and SUVTLR-FAPI [7.3 (2.0, 15.8) vs 1.7 (0.5, 6.9), P< 0.001], of IADT was significantly higher than that of GISTs, while there was no statistically significant difference in [18F]FDG PET/CT parameters, SUVmax-FDG and SUVTLR-FDG, between this two group. The ratio (SUVfapi/SUVfdg) of IADT was significantly higher than that of GISTs [3.3 (1.5, 8.0) vs 0.5 (0.1, 3.9), P= 0.001]. The SUVmax and SUVTLR of FAPI PET/CT of IADT were significantly higher than that of FDG PET/CT [8.8 (2.0, 16.0) vs 2.5 (1.1, 6.2), P< 0.001; 7.3 (2.0, 15.8) vs 0.9 (0.4, 2.7), P< 0.001; respectively]. FAP expression was found to be expressed in all the examined tissues and highly expressed in most of them. GEO database analysis shows that the FAP gene expression in DT is significantly higher than that in GISTs. Conclusions: FAPI PET/CT is a promising method in differentiating IADT from recurrence/metastases of GISTs compared with FDG PET/CT since FAP expression in DT is significantly higher than that in GISTs.

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

Liposarcoma is a malignant soft tissue tumor with several subtypes, the most common of which is well-differentiated liposarcoma (WDL) or atypical lipomatous tumor (ALT). WDL/ALTs are further divided into three histological subtypes, including lipoma-like, sclerosing, andinflammatory. While the majority of these tumors are predominantly fatty, the sclerosing variant demonstrates diverse histologic and radiographic characteristics, including variable amounts of fibrosis and fat. Because of this histological variability and relative rarity, the sclerosing WDL/ALT can present diagnostic dilemmas. We present two cases of sclerosing WDL/ALT, both of which demonstrated high degrees of fibrosis and a paucity of fat, mimicking desmoid fibromatosis and other fibrotic soft tissue tumors. Thus, it is important for radiologists to be aware of the subtypes of liposarcoma and their unique characteristics, and to consider sclerosing WDL/ALT in cases of fibrotic soft tissue tumors.

Desmoid fibromatosis is an aggressive fibroblastic neoplasm with a high propensity for local recurrence. Targeted therapy for Desmoid fibromatosis represents a novel avenue in systemic treatment. Anlotinib, a novel multitargeted angiogenesis inhibitor, represents a novel approach for targeted therapy. Therefore, this study aims to assess the efficacy and safety of anlotinib in patients with Desmoid fibromatosis. We retrospectively gathered the clinical medical records of Desmoid fibromatosis patients who underwent anlotinib treatment between June 2019 and November 2023 at our center. Anlotinib was initiated at a daily dose of 12 mg and adjusted based on drug-related toxicity. Tumor response was evaluated using the Response Evaluation Criteria in Solid Tumors 1.1 criteria. Progression-free survival served as the primary endpoint and was analyzed utilizing the Kaplan-Meier method. In total, sixty-six consecutive patients were enrolled. No patients achieved a complete response; however, fourteen patients (21.21%) exhibited a partial response, while forty-six patients (70%) experienced disease stability. Progressive disease was observed in 6 patients (9.10%), and the progression-free survival rates at 12 and 36months were 89.71% and 82.81%, respectively. The disease control rate was 90.91%, while the objective response rate was 21.21%. Anlotinib proves effective in managing recurrent and symptomatic patients with Desmoid fibromatosis. However, the toxicity profile of anlotinib presents a higher risk of Hand-Foot Skin Reaction and hypertension. Therefore, given that 41.67% of patients were subjected to dose adjustments associated with the initial dose of 12 mg, implementing dosage reductions may help balance efficacy with side effects.

Abstract Introduction: Disparities in cancer care in patients from different races and ethnicities unfortunately do exist and are well described in literature. Hormonal-driven cancers, such as some soft-tissue tumors and DCIS, have been demonstrated to impact African-American women (AAW) disproportionately. These patients are at increased risk for not only development of these cancers, but also experience disparities in survival, treatment outcomes, and modalities of treatment. Clinical Case: A 47-year-old premenopausal AAW with past medical history of recurrent desmoid sarcoma of the abdomen and ductal carcinoma in-situ (DCIS) of the left breast presented to oncology clinic with recurrent abdominal mass. The patient was originally diagnosed with DCIS in the left breast in 2018 and subsequently underwent left breast mastectomy with TRAM reconstruction and fat graft later that year. In 2020, the patient noticed a left lower abdominal growth that quickly enlarged and became painful. She underwent imaging without biopsy and was taken to surgery in April 2021 with tumor removal and mesh placement. Pathology showed desmoid fibromatosis infiltrating skeletal muscle and involving the inked resection margin of the specimen. Conservative re-excision and additional therapy was recommended but not done at the time. In 2022, the patient had resection of the area again with pathology of the incisional scar showing skin and deep soft tissue foci suspicious for recurrent desmoid fibromatosis extending to the inked deep margin. No mesh was placed, and the wound closed almost completely. The patient was not aware of positive margins at the time. In January 2023, patient again notice a new bump that was bothersome. Initial CT and MRI without finding of defined mass, but with right rectus thickening and enlarged right external iliac lymph node. Core biopsy in June 2023 confirmed recurrent desmoid fibromatosis. In April 2023, annual screening with mammogram was performed with a finding of 2.9 cm cluster of heterogenous calcification in the right breast. Diagnostic mammogram and ultrasound performed. Core needle biopsy was subsequently performed in May with pathology consistent with high grade DCIS with low ER and PR positivity. Lymph node biopsy was negative, but clinically positive. She is currently undergoing further genetic testing with surgical workup for mastectomy. Discussion and Conclusion: AAW diagnosed with DCIS have higher all-cause and disease specific mortality in comparison to white women (WW) diagnosed with DCIS. AAW are also at increased risk of aggressive secondary breast cancers in both the ipsilateral and contralateral breast in comparison to other races. In regards to tumor biology, WW have been shown to have higher ER and PR positivity in both primary and primary breast cancers than AAW. In many of these large-scale studies higher mortality, recurrence, and metastasis in AAW have been identified regardless of treatment modality. Research into differences in treatment between AAW and WW has shown that AAW, in contrast to our patient case, are more likely to undergo endocrine and radiation therapy rather than mastectomy. Although there does not seem to be an increased risk of desmoid fibromatosis in AAW when compared to WW, other soft-tissue tumors and malignancies do show a predilection for AAW. Incidence of sarcoma in black patients is higher than white patients, and black patients also have poorer survival outcomes. This case provides an example of the intersectionality of two cancer subtypes that impact black patients disproportionately. More evidence is required to unearth the reasons why these two cancer subtypes which are driven by similar processes impact AAW to a greater degree. Citation Format: Vinita Akula, Jessica Jones. Recurrent Desmoid Tumor and Ductal Carcinoma In Situ in an African-American Woman: A Case Report and Discussion on Disparities for These Two Cancer Subtypes [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-21-01.

Desmoid fibromatosis (DF) is a locally aggressive tumor with low mortality but significant morbidity. There is a lack of standard of care, and existing therapies are associated with significant barriers including access, cost, and toxicities. This study aimed to explore the efficacy and safety of the metronomic therapy (MT) in DF in a large, homogenous cohort from India. This study involved histologically confirmed DF cases treated with MT comprising vinblastine (6 mg) and methotrexate (15 mg) both once a week, and tamoxifen (40 mg/m2) in two divided doses once daily between 2002 and 2018. There were 315 patients with a median age of 27 years; the commonest site was extremity (142 of 315; 45.0%). There were 159 (50.1%) male patients. Of the 123 (39.0%) prior treated patients, 119 had surgery. Of 315 patients, 263 (83.5%) received treatment at our institute (MT-151, 77-local treatment, 9-tyrosine kinase inhibitor, and 26 were observed). Among the MT cohort (n = 163, 61.2%), at a median follow-up of 36 (0.5-186) months, the 3-year progression-free and overall survival were 81.1% (95% CI, 74.3 to 88.4) and 99.2% (95% CI, 97.6 to 100), respectively. There were 35% partial responses. Ninety-two patients (56.4%) completed 1-year therapy, which was an independent prognosticator (P < .0001; hazard ratio, 0.177 [95% CI, 0.083 to 0.377]). MT was well tolerated. Predominant grade ≥3 toxicities were febrile neutropenia, 12 (7.4%) without any chemotoxicity-related death. The annual cost of MT was $130 US dollars. The novel, low-cost MT qualifies as one of the effective, less toxic, sustainable, standard-of-care options for the treatment of DF with global reach and merits wide recognition.

To provide an update on the current state of percutaneous thermal ablation in the treatment of sarcoma. Data continue to accrue in support of ablation for local control and palliation of specific sarcoma subtypes such as extra-abdominal desmoid fibromatosis and for broader indications such as the treatment of oligometastatic disease. The synergistic possibilities of various combination therapies such as cryoablation and immunotherapy represent intriguing areas of active investigation. Histotripsy is an emerging non-invasive, non-thermal ablative modality that may further expand the therapeutic arsenal for sarcoma treatment. Percutaneous thermal ablation is a valuable tool in the multidisciplinary management of sarcoma, offering a minimally invasive adjunct to surgery and radiation therapy. Although there remains a paucity of high-level evidence specific to sarcomas, ablation techniques are demonstrably safe and effective for achieving local tumor control and providing pain relief in select patients and are of particular benefit in those with metastatic disease or requiring palliative care.

Susceptibility-weighted imaging (SWI) is based on a 3D high-spatial-resolution, velocity-corrected gradient-echo MRI sequence that uses magnitude and filtered-phase information to create images. It SWI uses tissue magnetic susceptibility differences to generate signal contrast that may arise from paramagnetic (hemosiderin), diamagnetic (minerals and calcifications) and ferromagnetic (metal) molecules. Distinguishing between calcification and blood products is possible through the filtered phase images, helping to visualize osteoblastic and osteolytic bone metastases or demonstrating calcifications and osteoid production in liposarcoma and osteosarcoma. When acquired in combination with the injection of an exogenous contrast agent, contrast-enhanced SWI (CE-SWI) can simultaneously detect the T2* susceptibility effect, T2 signal difference, contrast-induced T1 shortening, and out-of-phase fat and water chemical shift effect. Bone and soft tissue lesion SWI features have been described, including giant cell tumors in bone and synovial sarcomas in soft tissues. We expand on the appearance of benign soft-tissue lesions such as hemangioma, neurofibroma, pigmented villonodular synovitis, abscess, and hematoma. Most myxoid sarcomas demonstrate absent or just low-grade intra-tumoral hemorrhage at the baseline. CE-SWI shows superior differentiation between mature fibrotic T2* dark components and active enhancing T1 shortening components in desmoid fibromatosis. SWI has gained popularity in oncologic MSK imaging because of its sensitivity for displaying hemorrhage in soft tissue lesions, thereby helping to differentiate benign versus malignant soft tissue tumors. The ability to show the viable, enhancing portions of a soft tissue sarcoma separately from hemorrhagic/necrotic components also suggests its utility as a biomarker of tumor treatment response. It is essential to understand and appreciate the differences between spontaneous hemorrhage patterns in high-grade sarcomas and those occurring in the therapy-induced necrosis process in responding tumors. Ring-like hemosiderin SWI pattern is observed in successfully treated sarcomas. CE-SWI also demonstrates early promising results in separating the T2* blooming of healthy iron-loaded bone marrow from the T1-shortened enhancement in bone marrow that is displaced by the tumor. SWI and CE-SWI in MSK oncology learning objectives: SWI and CE-SWI can be used to identify calcifications on MRI. Certain SWI and CE-SWI patterns can correlate with tumor histologic type. CE-SWI can discriminate mature from immature components of desmoid tumors. CE-SWI patterns can help to assess treatment response in soft tissue sarcomas. Understanding CE-SWI patterns in post-surgical changes can also be useful in discriminating between residual and recurrent tumors with overlapping imaging features.

Desmoid fibromatosis (DF) is a rare, locally aggressive connective tissue malignancy primarily affecting musculoaponeurotic tissues, representing less than 3% of all neoplasms. This case report presents a 30-year-old male with cutaneous desmoid fibromatosis, a rare variant characterized by a painless, firm mass in the left shoulder region. Histopathological, immunohistochemical, and molecular analyses confirmed the diagnosis of desmoid cutaneous fibromatosis, with positive findings for nuclear beta-catenin. Management involved a multidisciplinary approach, with a conservative strategy due to the tumors size and location, emphasizing regular monitoring for recurrence. Differential diagnosis considerations included dermatomyofibroma and scar tissue. Treatment options for DF vary, with a shift towards observation as the primary strategy, particularly in cases where surgery may result in significant functional impairment. Medical treatment or surgery may be considered in symptomatic or progressive cases. Close surveillance and follow-up imaging are crucial for early detection of disease progression. cutaneous desmoid fibromatosis presents diagnostic challenges, highlighting the importance of early identification and biopsy to prevent misdiagnosis.

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.

Background: Desmoid fibromatosis (DF) is a pathological intermediate fibroblastoma that is difficult to control locally due to its invasive nature, especially in the extremities. Although anlotinib demonstrated efficacy in treating DF with tolerable safety, the impact of surgical intervention in conjunction with anlotinib administration on local control in patients with extremity DF remains undetermined. Methods: We conducted a retrospective examination of the clinical medical documentation belonging to patients with resectable DF of the extremities who were treated with surgery between January 2010 and June 2022. The patients were divided into two cohorts: surgery alone cohort and surgery combined with anlotinib group (surgery plus anlotinib cohort), crossover to surgery plus anlotinib cohort was admissible for patients in the surgery alone cohort who experienced disease recurrence postoperatively. Clinical data such as basic information, tumor location, anlotinib toxicity, time to recurrence, surgical complications, follow-up time, visual analogue scale (VAS) score and Musculoskeletal Tumor Society (MSTS) score at the last follow-up were collected. Results: In total, 48 consecutive patients (19 males and 29 females) with resectable DF of the extremities, including 25 patients in the surgery alone cohort, 23 patients in the surgery plus anlotinib cohort, and 10 patients who were transferred from the surgery alone cohort to the surgery plus anlotinib cohort. The VAS score at the last follow-up was 5 (IQR, 3-6) in the surgery alone cohort and 2 (IQR, 1-3) in the surgery plus anlotinib cohort, respectively; the MSTS score at the last follow-up was 19 (IQR, 16.5-24) in the surgery alone cohort and 27 (IQR, 25-28) in the surgery plus anlotinib cohort, respectively; these characteristics were statistically different between the two cohorts. The 3-year recurrence-free survival (RFS) of the surgery alone cohort and the surgery plus anlotinib cohort were 37.7% and 72.6%, respectively, and the difference was statistically significant (p = 0.022). Conclusion: Surgery combined with anlotinib appears to be effective in controlling local recurrence in patients with resectable DF of the extremities, and the side effects were acceptable.

A desmoid tumour, also known as aggressive fibrous tumour or desmoid fibromatosis, is a rare, benign tumour originating from connective tissue cells. Desmoid tumours account for approximately 0.03+% of all neoplasms and less than 3+% of all soft tissue tumours. The estimated incidence in the general population is 2 to 4 cases per million people per year [1]. Desmoid tumours are characterised by aggressive growth but typically do not metastasize. They often occur in young adults and preferably affect specific body regions such as the abdomen, shoulder, chest, or extremities. The exact cause of the condition is not fully understood, but genetic changes and hormonal factors may play a role. Symptoms of a desmoid tumour depend on its location and size, with pain, swelling, or restricted movement commonly occurring. A diagnosis is typically made through a tissue sample (biopsy) and imaging techniques such as MRI or CT [2]. To our knowledge, this is the first documented case of recurrence of a desmoid tumour in the scar at the donor site of a latissimus dorsi flap previously used for the reconstruction of desmoid resection in the lower leg.