Low-grade Myofibroblastic Sarcoma Research Articles

Low-Grade Myofibroblastic Sarcoma of Hard Palate-A Diagnostic Challenge with Review of Literature.

Low-grade myofibroblastic sarcoma (LGMS) is categorized as an extremely rare malignant neoplasia of myofibroblasts. To date, only 38 cases describing patients diagnosed with LGMS in the oro-maxillofacial region have been reported in the scientific literature. Here, we introduce a rare case report and, for the first time, also provide a recent update of the literature and a clear review regarding the immunohistochemical panel to diagnose this entity.

Surgical Management of a Rare Case of Low-Grade Myofibroblastic Sarcoma of the Larynx.

Low-grade myofibroblastic sarcoma (LGMS) of the larynx is an extremely rare entity. We report a case of LGMS in a 59-year-old man presenting with progressive hoarseness and a right laryngeal mass and there was no recurrence during the 6-month follow-up after the total laryngectomy.

Myofibroma with Atypical Features can Mimic Low-Grade Myofibroblastic Sarcoma: Two Paediatric Cases.

Myofibroma is a rare benign mesenchymal tumor that frequently affects the pediatric population with a predilection for the head and neck region. About 10% of myofibroma cases, presenting atypical features, can be misinterpreted as low-grade myofibroblastic sarcoma (LGMS), with therapeutic and prognostic impact. Here, we report two pediatric cases of benign myofibroblastic tumors, one of them showing typical characteristics of myofibroma, the other was an atypical myofibroma, which initially mimicked low-grade myofibroblastic sarcoma. Atypical myofibromas, despite its distinctive characteristics, follow a benign course, similar with typical myofibroma. It is necessary to distinguish atypical myofibroma from low-grade myofibroblastic sarcoma and avoid unnecessary invasive therapy.

Multiple Bone Involvement in Low-grade Myofibroblastic Sarcoma Demonstrated on 18F-FDG PET/CT.

A 68-year-old woman with low back pain for 2 months was admitted. T2-weighted fat-saturated imaging revealed hyperintense lesions in multiple lumbar regions, suggesting the possibility of bone metastases. Multiple osteolytic and mixed osteolytic-osteoblastic lesions with significant 18F-fluorodeoxyglucose (18F-FDG) uptake, as well as multiple osteoblastic lesions with mild 18F-FDG uptake, were observed on subsequent 18F-FDG positron emission tomography/computed tomography without an identifiable primary lesion. This patient was pathologically diagnosed with low-grade myofibroblastic sarcoma (LGMS) after biopsy and surgery. Although multiple bone involvement in LGMS is extremely rare, this case suggests that it should be considered in the differential diagnosis of multiple bone metastases.

Myofibroblastic sarcoma: A study of demographic and socioeconomic factors.

e23545 Background: Myofibroblastic sarcoma is a type of non-rhabdomyosarcoma soft tissue sarcoma originating from spindle cells of mesenchymal origin with myofibroblastic differentiation. First described in 1998, there is little known about the prognostic factors of this rare and relatively new cancer. This typically non-metastasizing tumor is primarily found in the head, neck, or extremities. Treatment focuses on tumor excision, and the 5-year overall survival of low-grade myofibroblastic sarcoma cancer is 72%. This study analyzed data from the National Cancer Database (NCDB) to understand how demographic factors contribute to the treatment and prognosis of myofibroblastic sarcoma. Methods: A retrospective cohort analysis was conducted on demographic factors of patients with confirmed myofibroblastic sarcoma (ICD-8825-3) using the NCDB from 2004-2020. Regression analysis was used to study trends of patient age, sex, race, education, insurance status, distance from facility, and Charles/Deyo score within this population. Results: A total of 111 patients (N = 111) were identified in the database with a confirmed diagnosis of myofibroblastic sarcoma from 2004 to 2020 with an increasing frequency of diagnoses per year (R^2 = 0.6283). The average age of diagnosis was 47.3 (SD = 24.17, range = 0 - 90 years). Although Myofibroblastic sarcoma appeared throughout the body, the most prominent sites were the long bones of the lower limb and associative joints (6%) followed by the uterus (5%). The majority of patients were white (83%), non-Hispanic (86%), and female (63%). A higher percentage of patients lived in metropolitan areas with a population greater than 1 million (58%) compared to smaller metropolitan, urban, or rural counties (42%). Most of the patients were treated at an academic/research program (30%) followed by a comprehensive community cancer program (21%). More facility locations were based in the Pacific (15%) and the Middle Atlantic (11%) regions. The primary payer at diagnosis was private insurance/managed care (44%) followed by Medicare (32%) and Medicaid (19%). Few patients (5%) received palliative care. Conclusions: To the best of our knowledge, this is the first NCDB analysis on Myofibroblastic sarcoma. Based on our dataset, Myofibroblastic sarcoma tends to occur in the long bones of the lower limb and associative joints which differed slightly from what we found in previous reports, which described the head and neck as the two areas of highest prevalence. This is the first time the socioeconomic factors have been described in the literature: these patients are more likely to be non-Hispanic, female individuals, living in smaller towns. This study offers insight on how much further investigation is required to better understand the impact of demographic and socioeconomic factors on early diagnosis and treatments.

Recurrent USP6 rearrangement in a subset of atypical myofibroblastic tumours of the soft tissues: low-grade myofibroblastic sarcoma or atypical/malignant nodular fasciitis?

Low-grade myofibroblastic sarcoma (LGMS) is a rarely metastasizing myofibroblastic tumour mostly affecting extremities and the head and neck of adults. Histologically, it shows long infiltrative fascicles of spindle cells with moderate nuclear atypia. By immunohistochemistry, it stains positive for smooth muscle actin (SMA) and sometimes for desmin. To date, no recurrent genetic abnormalities have been described. Ubiquitin-specific peptidase 6 (USP6) gene rearrangement is typically found in some benign bone and soft-tissue tumours including nodular fasciitis (NF), among others. Nevertheless, rare cases of USP6-rearranged tumours resembling NF with atypical features have been reported. One index case of LGMS of the deltoid in a 56-year-old man presented the THBS2::USP6 translocation by RNA sequencing (Archer FusionPlex Sarcoma v2 panel). Further screening of 11 cases of LGMS using fluorescent in situ hybridization (FISH) analysis with a USP6 break-apart probe identified two additional cases. These cases were investigated with RNA-sequencing, and a RRBP1::USP6 translocation was detected in one. The other case was not assessable because of low-quality RNA. Noteworthy, rearranged LGMSs presented distinctive features including variable multinodular/plexiform architecture, prominent vasculature with occasional wall thickening, scattered osteoclast-like multinucleated giant cells, and peripheral lymphoid aggregates. Our findings support the notion that among soft-tissue neoplasms with fibroblastic/myofibroblastic phenotype, USP6 rearrangement is not limited to benign tumours, and warrants further investigation of genetic changes in myofibroblastic sarcomas.

Detection of MDM2 gene amplification by fluorescence in situ hybridization and its diagnostic value in low-grade osteosarcoma

Objective: To investigate the diagnostic value of detecting MDM2 gene amplification by fluorescence in situ hybridization (FISH) in low-grade osteosarcoma (LGOS). Methods: Thirty cases of parosteal osteosarcoma (POS) and 14 cases of low-grade central osteosarcoma (LGCOS) from April 2009 to August 2022 at Beijing Jishuitan Hospital, Capital Medical University were analyzed for the presence of MDM2 gene amplification by FISH. Fifty-eight additional cases were used as negative controls (including 28 cases of fibrous dysplasia, 5 cases of giant cell tumor, 4 cases of conventional osteosarcoma, 2 cases each of periosteal osteosarcoma, reparative changes after fracture, pleomorphic undifferentiated sarcoma, low grade myofibroblastic sarcoma, fibrous dysplasia with malignant transformation, one case each of leiomyosarcoma, sclerosing epithelioid fibrosarcoma, malignant peripheral nerve sheath tumor, desmoplastic fibroma of bone, solitary fibrous tumor, aneurysmal bone cyst, clear cell chondrosarcoma, osteofibrous dysplasia, and 3 cases of unclassified spindle cell tumor). Results: Among the 30 patients with POS, 15 were male and 15 were female, ranging in age from 10 to 59 years (mean 35 years, median 30.5 years). Among the 14 patients with LGCOS, four were male and 10 were female, ranging in age from 15 to 56 years (mean 37 years, median 36 years). All except one case were successfully detected by FISH. MDM2 gene amplification was detected in 27 cases of POS (27/29,91.3%) and 8 cases of LGCOS (8/14). All the negative controls were negative for MDM2 gene amplification. The positive rate of MDM2 gene amplification was significantly different between the case group and the control group (P<0.05). The sensitivity and specificity of MDM2 gene amplification in diagnosing POS and LGCOS were 91.3% and 100.0%; and 57.1% and 100.0%, respectively. The sensitivity and specificity of MDM2 gene amplification in diagnosing LGOS (including POS and LGCOS) were 81.3% and 100.0%, respectively. In cases where MDM2 gene was amplified, the MDM2 amplified signal was clustered. Nine cases showed increased CEP12 signal different from polyploidy which was displayed as small and weak signal points or cloud flocculent and cluster signals. Conclusions: Detection of MDM2 gene amplification by FISH is a highly sensitive and specific marker for LGOS. The interpretation criteria for FISH detection of MDM2 amplification are currently not unified. The signal characteristics need more attention when interpreting.

A Systematic Review and Illustrative Case Presentation of Low-Grade Myofibroblastic Sarcoma (LGMS) of the Extremities.

Low-grade myofibroblastic sarcoma (LGMS) is a rare tumor entity which occurs in the subcutaneous and deep soft tissues; it is less common in the bone with a predilection for the extremities and the head and neck region. As confirming the diagnosis is difficult and treatment strategies are not standardized, we aimed to identify patient and tumor characteristics, and to summarize treatment strategies and their clinical outcomes to guide surgeons. Included were full articles reporting patients with histology of LGMS in the extremities, excluding tumors of the trunk. All patients underwent surgery but with different extend, from marginal to wide resection. Included studies should inform about local recurrence, metastasis, or evidence of disease, depending on the surgical treatment. We conducted a structured search using MEDLINE (via PubMed), Web of Science, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) to identify studies on low-grade myofibroblastic sarcoma of the extremities. Study designs like randomized controlled trials, systematic reviews, prospective trials, retrospective studies, and case reports were included. Prospective studies and comparative studies were not available at all. Therefore, meta-analysis was not possible and statistical analysis was purely descriptive. Of the 789 studies identified from our initial search, 17 studies including 59 cases reported LGMS of the extremities with the surgical treatment and clinical outcome and were therefore analyzed. In addition, we present the rare case and surgical management of a 28-year-old male patient with residual LGMS of the thumb after an initial incomplete resection. The current literature suggests that a wide excision with R0 margins should be considered the standard treatment for LGMS. In cases where surgery leads to significant functional impairment, individual options like free tissue transfer from a donor site have to be considered. Therefore, we also present an illustrative case. For all selected case series and case reports, a high risk of confounding, selection bias, information bias, and reporting bias must be anticipated. Nevertheless, this systematic review provides a comprehensive overview on surgical treatment and clinical outcomes in LGMS surgery of the extremities.

Low-grade malignant myofibroblastic sarcoma of the larynx: a case report.

Low-grade myofibroblastic sarcoma (LGMS) is a rare malignant mesenchymal tumor derived from myofibroblasts. It is commonly identified in the head and neck, and particularly in the oral cavity, but rarely in the larynx. In this case report, we describe a patient who presented with hoarseness and underwent electronic fiber laryngoscopy, which revealed a neoplasm on the surface of his left vocal cord. The vocal cord tumor was resected under general anesthesia, and a malignant LGMS was diagnosed on postoperative pathologic examination. The results of immunohistochemical staining of the sections for vimentin (diffuse +), actin (partial +), and desmin (-) were consistent with this diagnosis. The patient recovered well after the surgery, and there was no recurrence of the neoplasm.

An update on selected cutaneous (myo) fibroblastic mesenchymal tumors.

Cutaneous (myo)fibroblastic tumors constitute a group of tumors with overlapping clinicopathological features and variable biologic behavior. In the present review we focus on the histomorphology, immunohistochemical profile and molecular background of the following entities: dermatofibrosarcoma protuberans (DFSP), CD34-positive fibroblastic tumor (SCD34FT), myxoinflammatory sarcoma (MIFS), low-grade myofibroblastic sarcoma, solitary fibrous tumor and nodular fasciitis. Although some of these entities typically arise in deep-seated locations, they may occasionally present as cutaneous/superficial tumors and might be challenging to recognize. This review covers in depth the latest advances in molecular diagnostics and immunohistochemical markers that have significantly facilitated the correct classification and diagnosis of these neoplasms.

Risk Factors for Recurrence and the Role of Radiotherapy in Low-grade Myofibroblastic Sarcoma: A Systematic Review.

Low-grade myofibroblastic sarcoma (LGMS) is a rare malignancy that commonly occurs in the head and neck region. The role of radiotherapy has been unclear in treating LGMS and the risk factors for recurrence have remained undefined. The objective of this study is to determine risk factors for the recurrence of LGMS in the head and neck as well as the role of radiotherapy in the treatment of LGMS. A comprehensive review of the literature was performed through Pubmed leading to the inclusion of 36 articles after our inclusion and exclusion criteria were applied. Continuous variables were analyzed with a 2-tail unpaired t test. Categorical variables were assessed with the χ2 test or Fisher exact test. Logistic regression and multivariable logistic regression analysis with 95% CIs were used to obtain odds ratios. LGMS most commonly occurred in the oral cavity (49.2%). Half of all recurrences occurred in the paranasal sinuses/skull base. LGMS occurring at the paranasal sinuses/skull base had a significantly increased risk of recurrence compared with other subsites within the head and neck (odds ratio: -40; 95% CI: 2.190, 762.005; P = 0.013). The average time to recurrence of LGMS was 19.2 months. Adjuvant treatment with radiation did not improve recurrence rates. Sex, tumor size, or bony involvement were not found as risk factors for recurrence. Patients with LGMS of the paranasal sinuses and skull base are at high risk for recurrence and should be monitored closely. The role of adjuvant radiation treatment in these patients remains unclear.

LOW-GRADE MYOFIBROBLASTIC SARCOMA OF THE ORAL CAVITY

Low-grade myofibroblastic sarcoma (LGMS) represents a distinct atypical myofibroblastic tumor of deep soft tissues, with a head and neck predilection. It has a variety of appearances, from fasciitis-like or fibromatosis-like to fibrosarcoma-like. Here, a series of four cases from two different institutions is shown, represented by 2 men and 2 women presenting a nodular lesion, with equal distribution in maxilla and mandibula. Microscopically, all cases showed neoplasms formed by oval to spindle cells in a fibrous stroma with myxoid and dense areas, some atypical mitoses, and prominent nucleoli. These findings suggested a mesenchymal tumor. An immunohistochemical panel was performed, which showed positivity for smooth muscle actin (3 of 4 cases), HHF35 (2 of 4 cases), β-catenin (3 of 3 cases), calponin (2 of 4 cases), and Ki-67 (range 5-40%). H-Caldesmon was negative for all cases, demonstrating myofibroblastic and smooth muscle differentiation. The diagnosis of LGMS was confirmed in all cases. Low-grade myofibroblastic sarcoma (LGMS) represents a distinct atypical myofibroblastic tumor of deep soft tissues, with a head and neck predilection. It has a variety of appearances, from fasciitis-like or fibromatosis-like to fibrosarcoma-like. Here, a series of four cases from two different institutions is shown, represented by 2 men and 2 women presenting a nodular lesion, with equal distribution in maxilla and mandibula. Microscopically, all cases showed neoplasms formed by oval to spindle cells in a fibrous stroma with myxoid and dense areas, some atypical mitoses, and prominent nucleoli. These findings suggested a mesenchymal tumor. An immunohistochemical panel was performed, which showed positivity for smooth muscle actin (3 of 4 cases), HHF35 (2 of 4 cases), β-catenin (3 of 3 cases), calponin (2 of 4 cases), and Ki-67 (range 5-40%). H-Caldesmon was negative for all cases, demonstrating myofibroblastic and smooth muscle differentiation. The diagnosis of LGMS was confirmed in all cases.

Recurrent Giant Myofibroblastic Sarcoma of Neck in a Teenager: Overcoming Treatment Challenges

Sarcomas are rare tumors arising from a variety of mesenchymal tissues which are even rarer in head and neck region amounting 1% only of the 5% of sarcomas. About 80% of head and neck sarcomas originate in soft tissue while the remaining 20% arise from bone (Cormier and Pollock in J Clin 54:94−109, 2004). One among the commonly presenting variants of sarcomas in head and neck that our patient was diagnosed with is Low grade myofibroblastic sarcoma (LGMS). These even though uncommon have a predilection for head and neck region particularly the tongue (Mentzel et al. in Am J Surg Pathol 22:1228−38, 1998; Cai et al. in Virchows Arch 463:827−36, 2013; Meng et al. in Chin Med J 120:363–9, 2007; Demarosi et al. in Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 108:248–54, 2009). LGMS was reclassified as a distinct entity by the WHO classification of soft tissue tumors in 2002 (Qiu et al. in Oncol Lett 9:619−25, 2015). Oncological resection is the mainstay of treatment. In case of bulky tumor, resection and reconstruction would be challenging. We report a recurrent LGMS of 15-year-old girl who presented with a ginormous soft tissue swelling in her left neck region which made her day-to-day activities strenuous and made her non ambulatory and the line of treatment executed in order to get her back on feet, healthy & free of the debilitating tumor.

Clinical Outcome of Low-Grade Myofibroblastic Sarcoma in Japan: A Multicenter Study from the Japanese Musculoskeletal Oncology Group

This retrospective multicenter study aimed to analyze the clinical features and prognosis of 24 patients diagnosed with LGMS between 2002 and 2019 in the Japanese sarcoma network. Twenty-two cases were surgically treated and two cases were treated with radical radiotherapy (RT). The pathological margin was R0 in 14 cases, R1 in 7 cases, and R2 in 1 case. The best overall response in the two patients who underwent radical RT was one complete response and one partial response. Local relapse occurred in 20.8% of patients. Local relapse-free survival (LRFS) was 91.3% at 2 years and 75.4% at 5 years. In univariate analysis, tumors of 5 cm or more were significantly more likely to cause local relapse (p &lt; 0.01). In terms of the treatment of relapsed tumors, surgery was performed in two cases and radical RT was performed in three cases. None of the patients experienced a second local relapse. Disease-specific survival was 100% at 5 years. A wide excision aimed at the microscopically R0 margin is considered the standard treatment for LGMS. However, RT may be a viable option in unresectable cases or in cases where surgery is expected to cause significant functional impairment.

Low grade myofibroblastic sarcoma in paraspinal location: A case report with review of literature

Myofibroblasts were first detected in the granulation tissue and low-grade myofibroblastic sarcoma has now been recognized as a distinct entity. It has an indolent clinical course and distant metastasis is very rare. Hence surgical excision is the mainstay of the treatment. However, this tumor morphologically mimics other relatively high-grade soft tissue sarcomas, so distinguishing them is of utmost importance. Here we report, a 22-year-old young girl presented with neck pain and a slowly growing mass in the cervical paraspinal region. The patient was managed by wide local excision and the specimen was examined thoroughly. After considering all the features diagnosis of low-grade myofibroblastic sarcoma was offered.

Low-Grade Malignant Myofibroblastic Sarcoma of the Larynx: A Case Report and Literature Review.

Squamous cell carcinomas predominate in laryngeal malignancies, while spindle cell tumors, typically derived from non-epithelial tissues, are uncommon, accounting for 0.3%-1% of all malignant laryngeal tumors. Low-grade malignant myofibroblastic sarcoma (LGMS) is an extremely rare, atypical myofibroblastic tumor classified as a spindle cell tumor that primarily affects the head and neck region. There have been few reports in the literature regarding the LGMS of the larynx. LGMS of the larynx was discovered during a pathological biopsy. There was no recurrence during the 6-month follow-up after the total laryngectomy.

Huge Primary Intermediate-grade Myofibroblastic Sarcoma in the Retroperitoneum.

Myofibroblastic sarcoma is exceedingly rare, with low-grade features in most cases, and rarely involves the retroperitoneum. The 2020 World Health Organization (WHO) classification of soft tissue tumours still lists only low-grade myofibroblastic sarcoma and shows no consensus on the definitions of high- and intermediate-grade myofibroblastic sarcomas, in contrast to the 2013 WHO classification. Surgical resection of the tumour and adjacent structures is the standard of care for most patients, and intermediate- and high-grade myofibroblastic sarcomas have very poor survival. We describe a patient with intermediate-grade myofibroblastic sarcoma in the retroperitoneum, who underwent en bloc resection and ureteroplasty without adjuvant therapy and was free of pain and any other discomfort during 19 months of follow-up. Key Words: Myofibroblastic sarcoma, Intermediate grade, Retroperitoneum, Surgery.

A Case Report of Cutaneous Low-grade Myofibroblastic Sarcoma in the Neck

Myofibroblastic sarcoma can be classified as low-, intermediate-, and high-grade. Low-grade myofibroblastic sarcoma (LGMS) is uncommon and rarely appears on the skin. LGMS is diagnosed based on histopathological and immunohistochemical findings. Additionally, LGMS metastases are rare as well. Herein, the authors describe a case of cutaneous LGMS in the neck. To the best of our knowledge, there are no cases regarding cutaneous LGMS in the neck present in the existing literature. Surgical resection is considered as the most important treatment for LGMS. Therefore, a complete tumor resection was performed in this case. However, another mass in the uterus was identified on abdominal computed tomography performed post-surgery.

A rare low-grade myofibroblastic sarcoma in lower jaw with the resemblance to benign lesions

BackgroundLow-grade myofibroblastic sarcoma (LGMS) is a rare solid infiltrative soft tissue tumor with a predilection for the head and neck region.Case presentationWe report the diagnostic steps of a fast-growing lesion of the lower left jaw in a 45-year-old otherwise healthy woman. A first biopsy and subsequent histopathological examination showed potential differentials of a benign myofibroma, benign nodular fasciitis or an LGMS. This diagnostic overlap was a challenge for the decision of the further treatment approach. The treatment consisted of a segmental en bloc resection of the mandible including the second premolar, first and second molar. Histopathological examination of the resected tumor confirmed an LGMS.ConclusionThe histopathologic resemblance of LGMS to a range of benign and reactive tumors may lead to misdiagnosis and mistreatment. The rarity of LGMS explains the lack of established treatment protocols. This case shows the importance of adequate clinical decisions, expertise in the histopathology of rare tumors and interdisciplinary exchange to achieve state-of-the-art patient management.

IMMUNOHISTOCHEMICAL MARKERS FOR THE DIAGNOSIS OF ORAL SPINDLE CELL LESIONS: A REVIEW

<h3>Objectives</h3> To review the useful immunohistochemical markers in the diagnosis of spindle cell lesions of the oral cavity. <h3>Study Design</h3> A narrative review of the literature was carried out in PubMed and Portal Periódicos CAPES databases. Immunohistochemical profiles of myofibroblastic (myofibroma, inflammatory myofibroblastic tumor, low-grade myofibroblastic sarcoma), fibroblastic (solitary fibrous tumor, fibromatosis, nodular fasciitis, fibrosarcoma), and muscular (leiomyoma, angioleiomyoma, leiomyosarcoma) lesions was collected. <h3>Results</h3> A graphic summary of the results was elaborated. Of notice, h-caldesmon and smooth muscle myosin are helpful to differentiate myofibroblastic and muscular lesions. CD34, bcl-2, and CD99 are useful for diagnosing solitary fibrous tumor. The lack of desmin expression in myofibroma may help in the differentiation from leiomyoma. p53 and Ki-67 may help in the diagnosis of malignant lesions. <h3>Conclusions</h3> Immunohistochemistry is often useful to stablish the histopathologic diagnosis of oral spindle cell lesions of myofibroblastic, fibroblastic, and muscular origin, though a large panel can be necessary. H-caldesmon, smooth muscle actin, smooth muscle myosin, desmin, and muscle-specific actin are of great importance. Other markers such as CD99 and ALK-1 are useful for specific lesions.