Retroperitoneal low-grade fibromyxoid sarcoma.

Introduction: Low-grade fibromyxoid sarcoma is an uncommon deep-seated soft-tissue sarcoma that occurs rarely in young adults and children. Although surgical resection provides a long-term prognosis, late local recurrence and metastasis may occur. Case presentation: A 44-year-old woman with no prior medical history presented with breathing and abdominal discomfort. Contrast-enhanced computed tomography scan revealed a retroperitoneal tumor protruding into the thoracic cavity and pleural effusion on the left side. Tumor biopsy revealed sarcoma. We performed complete resection of the tumor along with part of the diaphragm and replaced the diaphragm with a prosthetic patch. Histopathologic findings indicated low-grade fibromyxoid sarcoma. The patient experienced no postoperative complications and received no adjuvant therapy. Furthermore, she survived 4 years after surgery without recurrence. Conclusion: Complete surgical resection is effective for low-grade fibromyxoid sarcoma; therefore, it is important to plan appropriately for complete resection when biopsy reveals malignant findings.

Supraclavicular Artery Island Flap for Treatment of Cervical Wound Defects and Persistent Cerebrospinal Fluid Leaks: A Technical Note and Systematic Review of the Literature.

BACKGROUND: Soft tissue defects and persistent cerebrospinal fluid (CSF) leaks can create complications after cervical spinal surgery. The supraclavicular artery island (SAI) flap is useful in closing tissue defects, particularly in these complex surgeries and multiple reinterventions. However, technical reports in this context are scarce. We describe application of the SAI flap technique to control persistent CSF leak in the first documented instance (to our knowledge) of a low-grade fibromyxoid sarcoma (LGFMS) in the cervical epidural space. Additionally, we conducted a comprehensive review of PubMed, Embase, and Google Scholar from their earliest records through December 17, 2023 using combined terms, "supraclavicular artery island flap AND spine" and "supraclavicular AND flap AND spine". TECHNICAL NOTE: A 56-year-old woman with arm pain and weakness presented with a cervical epidural mass extending from C4-C6 and associated spinal cord compression. She underwent a 3-level corpectomy and tumor resection. Primary dural closure was impossible due to the dural invasion, and reintervention with an SAI flap and definitive lumboperitoneal shunting were required to control and seal the CSF leak. SYSTEMATIC LITERATURE REVIEW: Seven case reports describing SAI flap for spinal surgery complications were identified. The indications in those cases were correcting esophageal and hypopharyngeal perforations after cervical fusion and discectomy and persistent soft tissue coverage after cervical instrumentation. CONCLUSIONS: The SAI flap technique provided wound defect coverage in this case and is suitable for addressing issues such as persistent CSF leaks or soft tissue coverage after cervical spine surgery.

Primary lung low-grade fibromyxoid sarcoma: A rare case with A diagnostic dilemma.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare, low-grade malignant soft tissue tumor that is often mistaken for benign or more rarely malignant tumor types. Commonly, this tumor affects young adults and typically arises in the deep proximal extremities or trunk with frequent recurrences and can metastasize to the lungs many years late. Visceral LGFMS is extremely rare. Only a few cases of primary LGFMS of the lung have been reported. Here, we present the clinical, gross, microscopic, and immunohistochemical characteristics of Evans tumor occurring in the lung with a review of the literature and discuss the differential diagnosis in this exceptional localization.

Novel KMT2B gene mutation in MUC4 positive low-grade fibromyxoid sarcoma.

BACKGROUND: Low-grade Fibromyxoid Sarcoma(LGFM)is a rare fibrosarcoma, which mainly occurs in young people and is mostly seen in the trunk and limbs. The tumor is usually FUS-CREB3L2 fusion caused by t(7;16)(q32-34;p11)chromosome translocation, and rarely FUS-CREB3L1 and EWSR1-CREB3L1 fusion. MUC4 diffuse strong positive can be used as a specific index of LGFM. LGFM is similar to Sclerosing Epithelioid Fibrosarcoma(SEF) and may have the same origin. CASE PRESENTATION: We report a case of LGFM in the chest wall. A female who is 59 years old. In 2016, CT showed dense nodule shadow and focal thickening of the left pleura, the patient underwent surgery, Pathological report that low to moderate malignant fibrosarcoma(fibromyxoid type). The CT re-examination in 2021 showed that the tumors on the left chest wall were significantly larger than before. Pathological examination showed the disease is composed of alternating collagen like and mucinous areas. Under high-power microscope, the tumor cells are consistent in shape, spindle or short spindle, and the tumor cells are arranged in bundles. In local areas, the density of tumor cells is significantly increased, mixed with collagen fibers, and small focal SEF appear. The result of immunohistochemistry showed that SMA, Desmin, CD34, STAT6, S100, SOX10, HMB45 and Melan A were negative, EMA was weakly positive, MUC4 was diffuse and strongly positive, and Ki67 index was low (3%). CONCLUSION: Sequencing results showed that MET, EGFR, KMT2B and RET gene were mutated in LGFM, and KMT2B gene had cancer promoting effect, but there was no literature report in LGFM, which may be of certain significance for the diagnosis and treatment of LGFM.

An elderly low-grade fibromyxoid sarcoma patient with early postoperative recurrences and metastases: a case report and literature review.

Background: Low-grade fibromyxoid sarcoma (LGFMS) is a rare type of soft tissue sarcoma that often involves the deep soft tissue of the extremities and trunk in young and middle-aged adults. It is uncommon in the elderly. Here we discuss a case of LGFMS in an elderly patient who had recurrence and metastasis within 2 years of resection of the primary tumor. Case report: A 71-year-old LGFMS patient was presented with a mass in the left forearm accompanied by pain and numbness from the left upper arm to fingers. The patient subsequently underwent 3 surgical resections, although she had 3 recurrences within 6 months after the initial diagnosis. Considering the malignant biological behavior of the tumor, an amputation at 5 cm above the elbow was eventually performed. However, recurrence in the extremity of the stump and chest wall metastasis were observed 2 years after amputation. Then resection of the metastases, radiotherapy and particle implantation therapy were performed. The patient is currently undergoing follow-up and has no evidence of recurrence. Conclusion: In our case, multiple early postoperative recurrences may be associated with a positive margin at initial operation. The patient underwent a total of 5 operations including local resection of the primary tumor, twice wide resections, amputation and metastatic surgery with 4 early postoperative recurrences and metastases within 4 years, suggesting that LGFMS may have highly invasive biological behavior. Our case demonstrated that early aggressive surgical treatment is recommended for LGFMS patients with a positive margin at initial operation and patients who had recurrence even after wide resection rather than local resection. Further research is needed to develop more effective treatment options for rapidly progress and highly aggressive LGFMS.

Thoracoscopic Wedge Resection for Low-Grade Fibromyxoid Sarcoma (Evans Tumor) with Massive Calcification and Originating from the Lung: A Rare Case in an Unexpected Location.

We encountered a rare case of low-grade fibromyxoid sarcoma, which is generally known as Evans tumor, with massive calcification originating from the lung. The patient was a 22-year-old man with Duchenne muscular dystrophy who was referred for a detailed investigation of an intrathoracic tumor with massive calcification. Although our preoperative diagnosis was a solitary fibrous tumor originating from the mediastinum or diaphragm, intraoperative thoracoscopy revealed the tumor arising from the left lower lobe without adhesion to the other organs. Considering his medical history, we aimed to preserve lung function and chose wedge resection, which completely removed the tumor. Based on the pathological findings, the tumor was diagnosed as low-grade fibromyxoid sarcoma with massive calcification originating from the lung. Although extremely rare, this tumor should be considered as a differential diagnosis for a solitary lung mass with massive calcification in young adults.

Familial multiple endocrine neoplasia type 1 with intrathoracic low-grade fibromyxoid sarcoma.

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN1) is a hereditary tumor syndrome characterized by endocrine tumors with mainly a parathyroid, pancreatic, or anterior pituitary origin. Low-grade fibromyxoid sarcoma (LGFMS) is a rare low-grade soft tissue tumor. There is one known report of a patient with MEN1 complicated by LGFMS, which is very rare. Our report represents the second documented case, providing valuable insights. CASE PRESENTATION: A 31-year-old man with the chief complaint of a cough underwent chest contrast-enhanced computed tomography, which revealed a giant hypoabsorptive tumor with a maximum diameter of 23 cm in the left thoracic cavity. The patient was diagnosed with MEN1, as he also possessed a pancreatic neuroendocrine tumor and parathyroid tumor, and because his father had been found to have MEN1. To control hypercalcemia, surgery for the parathyroid tumor was initially performed, followed by surgical resection of the giant thoracic tumor for diagnosis and treatment. Histopathological examination findings of the tumor resulted in a diagnosis of LGFMS. CONCLUSION: We experienced a very rare MEN1 with LGFMS. Although endocrine tumors generally occur more frequently in MEN1, non-endocrine tumors such as the present case should also be noted, reinforcing the importance of systemic imaging scrutiny in addition to early diagnosis and long-term follow-up of MEN1 patients.

Sclerosing Epithelioid Fibrosarcoma.

Sclerosing epithelioid fibrosarcoma (SEF) is a distinctive sarcoma that may arise in nearly any soft tissue site or bone. While there has been past controversy as to whether it is related to low-grade fibromyxoid sarcoma (LGFMS), it has been shown to behave far more aggressively than LGFMS. SEF has a propensity to metastasize to the lungs and bone and arise within the abdominal cavity. Histologically, it is characterized by uniform nuclei embedded in a densely collagenous stroma simulating osteoid. By immunohistochemistry, it is often strongly positive for MUC4. The majority (75%) have EWSR1 gene rearrangement, most commonly with CREB3L1 as a fusion partner, although a variety of FUS/EWSR1 and CREB3L1/CREB3L2/CREB3L3 fusions have been described in addition to others. SEF is currently recalcitrant to nearly all chemotherapy and radiation therapy.

Sclerosing epithelioid fibrosarcoma of bone with hybrid features: clinicopathologic, radiologic, and molecular analysis of three cases.

Sclerosing epithelioid fibrosarcoma (SEF) occurring as a primary bone tumor is exceptionally uncommon. Even more rare are cases of SEF that show morphologic overlap with low-grade fibromyxoid sarcoma (LGFMS). Such hybrid lesions arising within the bone have only rarely been reported in the literature. Due to their variegated histomorphology and non-specific radiologic features, these tumors may pose diagnostic difficulties. Herein we describe three molecularly confirmed primary bone cases of sclerosing epithelioid fibrosarcoma that demonstrated prominent areas showing the features of LGFMS and with areas resembling so-called hyalinizing spindle cell tumor with giant rosettes (HSCTGR). Two patients were female and one was male aged 26, 47, and 16, respectively. The tumors occurred in the femoral head, clavicle, and temporal bone. Imaging studies demonstrated relatively well-circumscribed radiolucent bone lesions with enhancement on MRI. Cortical breakthrough and soft tissue extension were present in one case. Histologically the tumors all demonstrated hyalinized areas with SEF-like morphology as well as spindled and myxoid areas with LGFMS-like morphology. Two cases demonstrated focal areas with rosette-like architecture as seen in HSCTGR. The tumors were all positive for MUC4 by immunohistochemistry and cytogenetics, fluorescence in-situ hybridization, and next-generation sequencing studies identified EWSR1 gene rearrangements confirming the diagnosis in all three cases.Hybrid SEF is exceedingly rare as a primary bone tumor and can be difficult to distinguish from other low-grade spindled and epithelioid lesions of bone. MUC4 positivity and identification of underlying EWSR1 gene rearrangements help support this diagnosis and exclude other tumor types.

Sclerosing Epithelioid Fibrosarcoma (SEF) versus Low Grade Fibromyxoid Sarcoma (LGFMS): Presentation and outcome in the nationwide NETSARC+ series of 330 patients over 13 years.

Sclerosing Epithelioid Fibrosarcoma (SEF) and Low Grade Fibromyxoid Sarcoma (LGFMS) are ultrarare sarcomas sharing common translocations whose natural history are not well known. We report on the nationwide exhaustive series of 330 patients with SEF or LGFMS in NETSARC+ since 2010. PATIENTS AND METHODS: NETSARC (netsarc.org) is a network of 26 reference sarcoma centers with specialized multidisciplinary tumor boards (MDTB). Since 2010, (i) pathological review has been mandatory for sarcoma,and (ii) tumour/patients' characteristics have been collected in the NETSARC+ nationwide database. The characteristics of patients with SEF and LGFMS and their outcome are compared. RESULTS: 35/73 (48%) and 125/257(49%) of patients with SEF and LGFMS were female. More visceral, bone and trunk primary sites were observed in SEF (p < 0.001). 30% of SEF vs 4% of LGFMS patients had metastasis at diagnosis (p < 0.0001). Median size of the primary tumor was 51 mm (range 10-90) for LGFMS vs 80 (20-320) for SEF (p < 0.001). Median age for LGFMS patients was 12 years younger than that of SEF patients (43 [range 4-98] vs 55 [range 10-91], p < 0.001). Neoadjuvant treatment was more often given to SEF (16% vs 9%, p = 0.05). More patients with LGFMS were operated first in reference centers (51% vs 26%, p < 0.001). The R0 rate on the operative specimen was 41% in LGFMS vs 16% in SEF (p < 0.001). Median event-free survival (EFS) of patients with SEF and LGFMS were 32 vs 136 months (p < 0.0001). The median overall survival (OS) was not reached. Fifty-months OS was 93% vs 81% for LGFMS vs SEF (p = 0.05). Median OS was 77 months after first relapse, similar for SEF and LGFMS. In multivariate analysis, age, tumor size, metastasis at diagnosis were independent prognostic factors for OS in LGFMS. CONCLUSIONS: Although sharing close molecular alterations, SEF and LGFMS have a different natural history, clinical presentation and outcome, with a higher risk of metastatic relapse in SEF. Survival after relapse is longer than with other sarcomas, and similar for SEF and LGFMS.

The Expression of Mucin-4 (MUC4) in Sarcomas Apart From Sclerosing Epithelioid Fibrosarcoma and Low-Grade Fibromyxoid Sarcoma.

Background Low-grade fibromyxoid sarcoma (LGFMS) and sclerosing epithelioid fibrosarcoma (SEF) are two rare but aggressive soft tissue sarcomas that can be difficult to distinguish due to histopathological similarities. The present study examines the diagnostic capacities of mucin-4 (MUC4), a transmembrane mucin, in identifying different types of sarcomas and broadens its evaluation to include a wide range of sarcomas. Methods Immunohistochemical (IHC) examination of tissue samples from various sarcomas was performed using a mouse anti-MUC4 monoclonal antibody. IHC was conducted on 4-mm thick formalin-fixed paraffin-embedded tissue sections after pressure cooker antigen retrieval with a mouse anti-MUC4 monoclonal antibody. Results MUC4 was shown to be highly expressed in SEF (n=13) and LGFMS (n=10), while focal positivity in synovial sarcoma (n=1). Other sarcomas, such as malignant peripheral nerve sheath tumors, fibrosarcoma, leiomyosarcoma, liposarcoma, and myxofibrosarcoma, exhibited no expression (n=0). These findings are consistent with previous research and support MUC4 specificity as a SEF and LGFMS marker. This study provides information on the diagnostic efficacy of MUC4, particularly in the context of certain subtypes. It not only helps our understanding of these unique instances, but it also provides context for histopathological and IHC findings in soft tissue sarcoma. Furthermore, this study investigates the influence of age and gender on MUC4 expression in a range of sarcomas, which was typically understudied in the literature and found no relation with expression of MUC4. Conclusion In conclusion, this study adds to our understanding of soft tissue sarcomas by emphasizing the crucial role of MUC4 in certain sarcoma subtypes while acknowledging the complex variety of the sarcoma landscape. Further research is needed to understand the molecular mechanism that governs marker expression patterns, as well as the therapeutic implications.

Low-grade Fibromyxoid Sarcoma With Massive Degeneration: A Case of Unusual Gross and Histological Features.

BACKGROUND: Low-grade fibromyxoid sarcoma (LGFMS) is a rare type of sarcoma which is observed in the soft tissue of proximal extremities, typically in young and middle-aged adults. It consists of a solid proliferation of bland spindle cells within collagenous and myxoid stroma. CASE REPORT: Herein, we report a case of LGFMS with massive degeneration and hyalinization. A 30-year-old man presented with a well-circumscribed mass measuring 15 cm in diameter in his left biceps femoris muscle. Marginal tumor resection was performed under the clinical diagnosis of an ancient schwannoma or chronic expanding hematoma (CEH). The resected tissue revealed a well-demarcated tumor mass with massive degeneration and hyalinization with focal calcification. Proliferation of spindle tumor cells with abundant collagenous stroma, which resembled the fibrous capsule of CEH, was observed exclusively in a small area of the periphery of the tumor. No nuclear palisading, myxoid stroma, or collagen rosettes were identified. Immunohistochemical analysis demonstrated that the spindle tumor cells expressed mucin 4 and epithelial membrane antigen. Reverse transcriptase-polymerase chain reaction analysis detected mRNA expression of fused in sarcoma::CAMP-responsive element binding protein 3-like protein 2 (FUS::CREB3L2) fusion gene. Thus, a final diagnosis of LGFMS with massive degeneration and FUS::CREB3L2 fusion was made. CONCLUSION: The recognition of massive degeneration and hyalinization as unusual features of LGFMS might be helpful to differentiate it from CEH and other benign spindle-cell tumors.

Fibrosarcoma with deceptive benign presentations: a report of two cases.

Low-grade fibromyxoid sarcoma and myxofibrosarcoma are malignant soft tissue tumors, fibrosarcomas, of shared clinical and imaging appearances. We report sarcomatous lesions in soft tissue with deceptively benign clinical and imaging appearances, and correlate findings with those of histologic analysis. Two patients presented with a long history of painless swelling at the dorsum and upper extremity and denied any constitutional symptoms. Sonography and magnetic resonance imaging suggested the presence of benign soft tissue lesions of a predominant fluid-like consistency. Despite indolent clinical and imaging characteristics, in both cases, histopathology disclosed a diagnosis of spindle cell-type soft tissue sarcoma, designating an aggressive tumor. Knowledge of the seemingly benign clinical and imaging features of fibrosarcomas is required to raise the possibility of malignancy in soft tissue that may be underdiagnosed or misdiagnosed. The importance of a correct diagnosis and the implications of surgical resection, irradiation, and systemic oncological therapy are quite obvious.

A rare case report of pancreatic low-grade fibromyxoid sarcoma (LGFMS).

BACKGROUND: Low-grade fibromyxoid sarcoma (LGFMS) is an uncommon neoplasm generally affecting muscle tissue. It presents rarely in abdominal viscera and even more rarely occurs in the pancreas. All types of pancreatic sarcomas are uncommon, and LGFMS is a rarer still. We present the case of an LGFMS in the pancreas. Because of its rarity, there are no guidelines for appropriate treatment or summations of the natural course of this illness. CASE PRESENTATION: We present the case of a 49-year-old female who presented with epigastric pain. She had a prior history of three episodes of acute pancreatitis many years earlier. A CT revealed a pancreatic body mass, which was biopsied. Pathology returned LGFMS. The patient underwent a distal pancreatectomy and splenectomy. She did well after the case and did not require further intervention. CONCLUSION: Though it is exceedingly rare, cases of pancreatic LGFMS should be reported in order to guide clinical decisions. LGFMS has been shown to have high malignant potential in other tissues, and there is no reason to think pancreatic masses will be different. By building a body of evidence about these rare tumors, patient care will benefit.

Low-grade fibromyxoid sarcoma of the breast: genetic characterization and immunohistochemical comparison to morphologic mimics.

Spindle cell lesions of the breast elicit a specific, relatively limited differential diagnosis, and accurate classification often requires careful morphologic evaluation and immunohistochemical workup. Low-grade fibromyxoid sarcoma (LGFMS) is a rare malignant fibroblastic tumor with deceptively bland spindle cell morphology. Involvement of the breast is exceedingly rare. We examined the clinicopathologic and molecular characteristics of three cases of breast/axillary LGFMS. In addition, we interrogated the immunohistochemical expression of MUC4, a commonly used marker of LGFMS, in other breast spindle cell lesions. LGFMS presented in women at 23, 33, and 59 years of age. Tumor size ranged from 0.9 to 4.7 cm. Microscopically, they were circumscribed nodular masses composed of bland spindle cells with fibromyxoid stroma. Immunohistochemically, tumors were diffusely positive for MUC4 and negative for keratin, CD34, S100 protein, and nuclear beta-catenin. Fluorescence in-situ hybridization demonstrated FUS (n = 2) or EWSR1 (n = 1) rearrangements. Next-generation sequencing identified FUS::CREB3L2 and EWSR1::CREB3L1 fusions. MUC4 immunohistochemistry performed on 162 additional breast lesions demonstrated only weak and limited expression in a subset of cases of fibromatosis (10/20, ≤30% staining), scar (5/9, ≤10%), metaplastic carcinoma (4/23, ≤5%), and phyllodes tumor (3/74, ≤10%). MUC4 was entirely negative in cases of pseudoangiomatous stromal hyperplasia (n = 9), myofibroblastoma (n = 6), periductal stromal tumor (n = 3), and cellular/juvenile fibroadenoma (n = 21). LGFMS can rarely occur in the breast and should be considered in the differential diagnosis of breast spindle cell lesions. Strong and diffuse MUC4 expression is highly specific in this histologic context. Detection of an FUS or EWSR1 rearrangement can confirm the diagnosis.

Penoscrotal Low-grade fibromyxoid sarcoma, A case report.

Low-grade fibromyxoid sarcoma (LGFMS) is a subtype of sarcoma that commonly arises from the deep soft tissue. We present a case of LGFMS originated from the penoscrotal junction area, which highlights the unusual site of LGFMS presentation.The patient presented with a mass in the left base of the penis, which was resected and the pathology report was compatible with LGFMS. However, local recurrence near the primary tumor site was detected 3 months postoperatively, and re-excision confirmed the same diagnosis. This is the first report of LGFMS in the penoscrotal junction area as an uncommon site of this tumor.

Low-Grade Fibromyxoid Sarcoma of the Abdominal Wall: A Clinical Case Report.

Low-grade fibromyxoid sarcoma (LGFMS) is a soft tissue neoplasm that occurs preferentially in young, male adults as a slowly growing, asymptomatic mass. According to current literature, the most common anatomical sites where it occurs are the trunk and lower extremities, especially the thigh, perineum, and groin. The risk factors are still unknown. Surgical intervention (simple resection and wide excision) is nowadays considered the best treatment option; however, patients require a long follow-up due to the high recurrence and metastasis rates. We present a low-grade fibromyxoid sarcoma case located in the abdominal wall of a female Hispanic patient.

Sclerosing Epithelioid Fibrosarcoma of the Liver in a Pediatric Patient.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare but aggressive sarcoma. We report the first case of hepatic SEF in pediatric patient, which is also the second case in literature. A 17-year-old previously healthy female presented with a liver mass measuring 13.7 cm in greatest dimension and mild elevation of liver enzymes and cancer antigen 19-9. Needle biopsy revealed multiple cores of liver parenchyma mostly replaced by densely hyalinized fibrotic tissue and areas of small-to-medium sized epithelioid cells with eosinophilic and clear cytoplasm. Immunohistochemistry (IHC) demonstrated diffuse strong cytoplasmic staining of MUC4, suggesting a working diagnosis of sclerosing epithelioid fibrosarcoma (SEF)/low-grade fibromyxoid sarcoma (LGFMS). Liver explant demonstrated a well-circumscribed, nodular mass with firm, gray-white cut surface, and similar histopathology as seen in needle biopsy with no convincing evidence suggesting LGFMS. Sequencing panel revealed EWSR1::CREB3L1 gene fusion and confirmed the diagnosis of SEF. Post-operative cancer antigen 19-9 normalized 3 months after transplant; follow-up 3 and 6 months post-transplant imaging at that time showed no concern for disease recurrence.

Low-Grade Fibromyxoid Sarcoma of the Distal Upper Extremity: A Systematic Review.

BACKGROUND: Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft-tissue tumor that usually occurs in the proximal extremities and trunk. The purpose of this systematic review was to assess patient demographics, treatment approach, and outcomes for patients with LGFMS of the distal upper extremity. METHODS: We performed a literature review of case reports and patient reports of LGFMS using Medical Literature Analysis and Retrieval System Online (MEDLINE) and PubMed. Inclusion criteria included case reports and case series of patients with LGFMS of the distal upper extremity. Animal studies, comments, and non-English publications were excluded. Data on available patient demographics, treatment regimen, recurrence, and metastasis were collected. RESULTS: A total of 365 publications were reviewed. After applying the inclusion and exclusion criteria, 19 articles were included. There were 24 unique patients with LGFMS of the distal upper extremity. The median age was 32 years, and most patients were treated with a surgical excision. Of the 15 reported outcomes, 4 patients had local recurrences, and no patient had metastases or died due to the tumor. CONCLUSIONS: Although LGFMS of the distal upper extremity is less common, it is critical for surgeons to consider it as a differential. The current approach is a wide excision with negative margins, and chemotherapy or radiotherapy may not be necessary. We found decreased proportions of local recurrence and metastases in the distal upper extremity compared with other anatomical regions. We recommend that surgeons follow up with their patients indefinitely given the slow mitotic rate of LGFMS.

Reconstrucción de aparato extensor en sarcoma fibromixoide de bajo grado en rodilla: reporte de caso

Introducción: El sarcoma fibromixoide de bajo grado es una tumoración maligna con alto riesgo de desarrollar recurrencia y metástasis, siendo la resección quirúrgica con márgenes amplios el tratamiento principal, la preservación de la extremidad y su reconstrucción es de alta demanda para los cirujanos. Reporte de caso: Presentamos el caso de una mujer de 67 años con recurrencia de tumoración en rodilla desde hace 12 meses, operado dos años antes. Se realizo resección oncológica de tumoración con reconstrucción de articulación de rodilla con prótesis Endo Model y reconstrucción de aparato extensor con injerto sintético de malla de polipropileno más autoinjerto de semitendinoso y gracilis. La patela se reconstruyó con autoinjerto de cóndilo femoral posterior. A los 16 meses de seguimiento la paciente se encuentra libre de enfermedad, con puntaje de 27 en la escala para miembro inferior de la MSTS (Musculoskeletal Tumour Society). Conclusión: La combinación de injerto sintético con autoinjerto de isquiotibiales puede disminuir la tasa de falla de la reconstrucción del aparato extensor por resecciones oncológicas.

Introduction: Low-grade fibromyxoid sarcoma is a malignant tumor with a high risk of developing recurrence and metastasis, surgical resection with wide margins is the main treatment, limb preservation and reconstruction is in high demand for surgeons. Case of report: We present the case of a 67-year-old woman with a recurrence of a knee tumor that had been operated on two year earlier. Oncological resection of the tumor was performed with reconstruction of the knee joint with an Endo Model prosthesis and extensor mechanism reconstruction with a synthetic polypropylene mesh graft plus a semitendinosus and gracilis autograft. The patella was reconstructed with posterior femoral condyle autograft. At 16 months of patient follow-up, she is free of disease, with a score of 27 on the lower limb scale of the MSTS (Musculoskeletal Tumor Society). Conclusion: The combination of synthetic graft with hamstring autograft can reduce the failure rate of extensor mechanism reconstruction due to oncological resections.