Low-grade myofibroblastic sarcoma of the oral cavity

Myofibrosarcoma of Maxilla - Case Report and Review of Literature

Myofibrosarcoma is a distinct mesenchymal malignancy which commonly occurs in head and neck region. It has a high tendency for local recurrence and distant metastasis. 39-year-old male presented with epistaxis, nasal obstruction and left sided complete loss of vision. He underwent functional endoscopic sinus surgery and guided biopsy. MRI scan showed a lesion epicentred in the left maxillary sinus, superiorly extending into the orbit. He underwent Class 4b maxillectomy with neck dissection, tracheostomy and free flap reconstruction. Histopathological examination yielded final diagnosis as myofibrosarcoma of maxilla. The patient was planned for adjuvant radiotherapy and has been disease free for 3 years.

Low-grade myofibrosarcoma of the maxillary sinus: Two case reports

BACKGROUND

Low-grade myofibroblastic sarcoma (LGMS) is an extremely rare tumor characterized by the malignant proliferation of myofibroblasts. LGMS most commonly develops in adults, predominantly in males, in the head and neck region, oral cavity, especially on the tongue, mandible, and larynx. This article presents 2 cases of LGMS localized to the maxillary sinus and provides an overview of the available literature.

CASE SUMMARY

Two patients with LGMS located in the maxillary sinus underwent surgery at the Department of Head and Neck Surgery. Case 1: A 46-year-old patient was admitted to the clinic with suspected LGMS recurrence in the right maxillary sinus (rT4aN0M0), with symptoms of pain in the suborbital area, watering of the right eye, thick discharge from the right nostril, and augmented facial asymmetry. After open biopsy-confirmed LGMS, the patient underwent expanded maxillectomy of the right side with immediate palate reconstruction using a microvascular skin flap harvested surgically from the middle arm. The patient qualified for adjuvant radiotherapy for the postoperative bed, with an additional margin. Currently, the patient is under 1.5 years of observation with no evidence of disease. Case 2: A 45-year-old man was admitted to our clinic with facial asymmetry, strabismus, exophthalmos, and visual impairment in the right eye. Six months earlier, the patient had undergone partial jaw resection at another hospital for fibromatosis. A contrast-enhanced computed tomography scan revealed a tumor mass in the postoperative log after an earlier procedure. An open biopsy confirmed low-grade fibrosarcoma (rT4aN0M0). The patient qualified for an extended total right maxillectomy with orbital excision and right hemimandibulectomy with immediate microvascular reconstruction using an anterolateral thigh flap. The patient subsequently underwent adjuvant radiotherapy to the postoperative area. After 9 months, recurrence occurred in the right mandibular arch below the irradiated area. The lesion infiltrated the base of the skull, which warranted the withdrawal of radiotherapy and salvage surgery. The patient qualified for palliative chemotherapy with a regimen of doxorubicin + dacarbazine + cyclophosphamide and palliative radiotherapy for bone metastases. The patient died 26 months after surgical treatment. The cases have been assessed and compared with cases in the literature.

CONCLUSION

No specific diagnostic criteria or treatment strategies have been developed for LGMS. The treatment used for LGMS is the same as that used for sinonasal cancer radical tumor excision; adjuvant radiotherapy or chemoradiotherapy should also be considered. They have low malignant potential but are highly invasive, tend to recur, and metastasize to distant sites. Patients should undergo regular follow-up examinations to detect recurrence or metastasis at an early stage. Patients should be treated and observed at the highest referral centers.

Unusual Presentation of Tonsillar Spindle Cell Neoplasm: A Case Report

Spindle cell neoplasm of the tonsil are rare (Minami et al. in Am J Otolaryngol 29(2):123-125, 2008) and can be difficult to diagnose due to their non-specific clinical presentation and histological characteristics (Su et al. in J Chin Med Assoc 69(10):478-483, 2006). Differential diagnoses include lymphoma and squamous cell carcinoma (Hyams in Clin Otolaryngol Allied Sci 3(2):117-126, 1978). Oropharyngeal spindle cell neoplasms were more likely to occur in the tongue base and tonsil (58%) (Gerry et al. in Ann Otol Rhinol Laryngol 123(8):576-583, 2014). In this article, we report a case of tonsillar spindle cell neoplasm which is extremely rare.

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

INTRODUCTION

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.

METHODS

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.

RESULTS

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 Myofibroblastic Sarcoma on Back with Repeated Localized Recurrence and Regional Metastasis

Low-grade myofibroblastic sarcoma (LGMS) is a rare spindle cell tumor with indolent course. Due to rarity and low-grade histologic features of LGMS, accurate diagnosis is challenging. We report a 63-year-old female patient with a three-month history of a 3.1 cm×2.5 cm sized, firm, skin-colored, painless, protruding left back mass. Initial excisional biopsy was performed and the mass was diagnosed as nodular fasciitis. After 18 months after excision, the mass recurred with pain and grew larger. Considering the clinical manifestations, diagnostic impression was changed as dermatofibrosarcoma protuberans not nodular fasciitis. Second wide excision was performed and the histopathology revealed proliferative atypical spindle cells with moderate nuclear atypia and a distinctive whorling pattern, which is suggestive of low-grade sarcoma. Additional computed tomography and positron emission tomography revealed no metastasis and suspicious residual viable malignant tissue. To remove suspicious residual tumor, third wide excision were performed and the diagnosis confirmed as LGMS. A microscopically clear resection was achieved with deep and lateral safety margin 0.6 cm each. Despite of postoperative radiotherapy with 35 times, recurrence of the tumor and lung metastasis was found after 7 months later. LGMS rarely metastasizes and occurs most commonly in the head and neck region. Thus, we report a rare case of LGMS on back which repeated localized recurrence and regional lung metastasis occurred despite wide excision and adjuvant radiotherapy.

Low-Grade Myofibroblastic Sarcoma of the Oral and Maxillofacial Region: An International Clinicopathologic Study of 13 Cases and Literature Review

Low-grade myofibroblastic sarcoma (LGMS) represents an atypical tumor composed of myofibroblasts with a variety of histological patterns and with a high tendency to local recurrence and a low probability of distant metastases. LGMS has predilection for the head and neck regions, especially the oral cavity. This study aimed to report 13 new cases of LGMS arising in the oral and maxillofacial region. This study included LGMS cases from five oral and maxillofacial pathology laboratories in four different countries (Brazil, Peru, Guatemala, and South Africa). Their clinical, radiographic, histopathological, and immunohistochemical findings were evaluated. In this current international case series, most patients were females with a mean age of 38.7 years, and commonly presenting a nodular lesion in maxilla. Microscopically, all cases showed a neoplasm formed by oval to spindle cells in a fibrous stroma with myxoid and dense areas, some atypical mitoses, and prominent nucleoli. The immunohistochemical panel showed positivity for smooth muscle actin (12 of 13 cases), HHF35 (2 of 4 cases), β-catenin (3 of 5 cases), desmin (3 of 11 cases), and Ki-67 (range from 5 to 50%). H-caldesmon was negative for all cases. The diagnosis of LGMS was confirmed in all cases. LGMS shows predominance in young adults, with a slight predilection for the female sex, and maxillary region. LGMS should be a differential diagnosis of myofibroblastic lesions that show a proliferation of spindle cells in a fibrous stroma with myxoid and dense areas and some atypical mitoses, supporting the diagnosis with a complementary immunohistochemical study. Complete surgical excision with clear margins is the treatment of choice. However, long-term follow-up information is required before definitive conclusions can be drawn regarding the incidence of recurrence and the possibility of metastasis.

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 χ 2 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.

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.

Low-grade myofibroblastic sarcoma of the mandible: A rare tumour of childhood

Low-grade myofibroblastic sarcoma is a rare and indolent tumour of soft tissue. This tumour is relatively common in the head and neck region followed by extremities. Primary low-grade myofibroblastic sarcoma of the mandible is very rarely reported and the occurrence of this tumour in a child is very unusual. A 7-year-old male child presented with a swelling in right angle of mandible. X-ray and computed tomography scan showed a lytic lesion. The lesion was excised and the tissue was sent for histopathological evaluation, which revealed a cellular spindle cell neoplasm arranged in fascicles. The tumour was partly circumscribed and lobulated. On immunohistochemistry (IHC), these tumour cells showed cytoplasmic positivity for vimentin, and smooth muscle actin showed 'tram-track' pattern of positivity. The case was diagnosed as low-grade myofibroblastic sarcoma. There are no definite clinical features or pathognomonic radiological appearances of this tumour that can differentiate this rare tumour from other commonly encountered gnathic bone tumours, such as osteosarcoma, inflammatory myofibroblastic tumour, etc., Histopathological diagnosis coupled with ancillary investigations such as IHC is important to establish a definite diagnosis and rule out the differentials. The exact biological behaviour of this tumour is not known.

Low-grade myofibroblastic sarcoma of the proximal femur: A case report and literature review

RATIONAL

Low-grade myofibroblastic sarcoma (LGMS) is an atypical type of tumor composed of myofibroblasts. LGMS in the femoral head neck junction is extremely rare and no case treated by hip arthroscopy was reported.

PATIENT CONCERNS

We reported a case of LGMS in the femoral head neck junction treated by hip arthroscopy. A 30-year-old female was admitted to our hospital with discomfort and pain after left hip sprained one year prior. Physical examination revealed swelling of the left hip and magnetic resonance images showed a soft tissue mass in the femoral head neck junction.

DIAGNOSIS

Via microscopy of pathological specimens, spindle cell proliferative lesions, atypia of some cells, and mitotic figures/pathological mitotic figures of some cells were observed. Immunohistochemistry revealed positive for smooth muscle actin, focally positive for CD34 and CD68, while negative for S-100, desmin, and anaplastic lymphoma kinase. The imaging, histomorphological and immunohistochemical features suggested a final diagnosis of LGMS of the proximal femur.

INTERVENTIONS

This patient underwent hip arthroscopy for excision of the soft tissue mass.

OUTCOMES

The clinical and imaging follow-up at 6 months postoperatively showed that surgery had achieved good clinical outcomes.

LESSONS

To the best of our knowledge, this is the first case report of LGMS in the femoral head neck junction treated by hip arthroscopy. Beyond the present case, other 120 cases from 58 literatures (1998-2022) are reviewed and discussed. The age of LGMS patients ranged from 11 months to 77 years and the male-to-female ratio was approximately 1.28:1. The location distribution of previously reported LGMS cases and the present case was as follows: Head&neck (45.90%), trunk (30.33%), and extremity (23.77%). Hip arthroscopic excision of LGMS may achieve relatively good clinical outcomes.

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

Background

Low-grade myofibroblastic sarcoma (LGMS) is a rare solid infiltrative soft tissue tumor with a predilection for the head and neck region.

Case presentation

We 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.

Conclusion

The 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.

Surgical treatment and long-term outcomes of low-grade myofibroblastic sarcoma: a single-center case series of 15 patients

Background

Low-grade myofibroblastic sarcoma (LGMS) is a poorly studied, rare, soft tissue sarcoma. LGMS is characterized by a low malignancy potential, tendency for local recurrence, and low likelihood of distant metastases. However, no studies have reported on the surgical treatment method and its long-term outcomes.

Methods

We included all patients treated for LGMS at our institution between March 2010 and March 2021. Medical charts were retrospectively reviewed to collect demographic information, as well as information about the clinical course, tumor characteristics, and outcomes. Statistical analysis was performed to identify the factors associated with the recurrence rate.

Results

Fifteen patients who underwent surgical treatment were enrolled in this study. There were seven cases in the upper extremities, four in the trunk area, three in the lower extremities, and one in the head and neck area. There were no metastatic cases and two cases of local recurrence.

Conclusions

The incidence of LGMS in the extremities or trunk may be higher than expected based on the current literature. Univariate analysis showed that local tissue invasion and surgical method could be associated with local recurrence. Although further large studies are needed to establish risk factors of local recurrence or extent of resection margins, based on our study, wide local excision under the proper diagnosis is the most important treatment.

Sarcomas of the Larynx: One Institution's Experience and Treatment Protocol Analyses

Soft tissue sarcomas in the head and neck are rare malignancies. They occur in this area in less than 1% of all malignant tumors. Some authors have described the development of sarcoma from the mesenchymal tissue in the larynx. The histological diagnosis of a sarcoma depends on the immunohistochemical investigation. In particularly difficult diagnoses, electron microscopy has to be used. The treatment recommendation depends on the histological type of sarcoma. We analysed and summarized data on the diagnostic criteria and therapy for sarcoma of the larynx presented in the literature. We present three new cases of laryngeal sarcoma and describe the analyses of the published diagnostic and treatment schedules of laryngeal sarcomas. We developed a treatment protocol recommendation for laryngeal sarcoma based on an analysis of literature data and case reports. This recommendation is based on histological type, staging, grading, size, and survival data.

Low-Grade Myofibroblastic Sarcoma of the Oral Cavity: A Report of Three Cases Illustrating an Emerging Disease in Children

Low-grade myofibroblastic sarcoma (LGMS) is a mesenchymal tumor of myofibroblasts that occurs more frequently in adults. A series of three cases is presented to illustrate that LGMS may also occur within the oral cavity in children and adolescents. The first case (Case 1) occurred intra-osseously in the mandible, while the remaining two presented as gingival swellings and were purely restricted to soft tissue (Cases 2 and 3). The intra-osseous lesion arose in a 7-year-old girl, whereas the gingival lesions were observed in a 12-year-old girl (Case 2) and a 13-year-old boy (Case 3). Histopathologically, all cases were composed of spindle shaped cells arranged into long fascicles showing mild to moderate degree of nuclear atypia. Ki-67 (MIB-1) proliferation activity was relatively low, amounting to 3–5% in all cases. Immunohistochemically, all cases showed smooth muscle actin (SMA) positivity in spindle cells, while desmin, beta catenin, cytokeratin, and CD34 were negative, resulting in a diagnosis of LGMS. In conclusion, current series of three cases of LGMSs that occurred in the oral cavity in a child and two adolescent patients is presented to highlight an emerging disease that requires additional data for further characterization.

Low-grade myofibroblastic sarcoma of the levator scapulae muscle: a case report and literature review

BACKGROUND

Low-grade myofibroblastic sarcoma (LGMS) is described as a distinct atypical myofibroblastic tumor often with fibromatosis-like features and predilection for the head and neck, especially the oral cavity and larynx. LGMS arising in the levator scapulae muscle is extremely rare.

CASE PRESENTATION

A 69-year-old woman was admitted to our hospital because she noticed a hard mass in her left neck six months prior. Magnetic resonance images (MRI) showed a soft tissue tumor of the left levator scapulae muscle. A core needle biopsy showed cellular fascicles or a storiform growth pattern of spindle-shaped tumor cells with minimally atypia. Immunohistochemistry revealed focally positive for α-smooth muscle actin (α-SMA), negative for S-100, and a low-grade spindle cell sarcoma was suspected. Following a biopsy, the tumor was resected with a wide surgical margin. Immunohistochemical staining was a positive for vimentin and α-SMA and negative for desmin, CD34, nuclear β-catenin, and h-caldesmon. LGMS diagnosis was determined based on the histopathological findings. The patient was alive with no evidence of disease eight years after the surgery.

CONCLUSIONS

To the best of our knowledge, this is the first case report of LGMS arising in the levator scapulae muscle. In addition to the case report, 48 reports with 103 LGMS cases are reviewed and discussed. In previous reports of LGMS, there were 43 females and 60 males, with a mean age of 43.0 years (range, 2-75). There were 13 (12.6%) patients aged < 18 years, 67 (65.1%) patients aged 18 to 59 years, and 23 (22.3%) patients aged ≥60 years. The average tumor size was 4.4 cm (range: 0.4-22.0). The commonest sites of LGMS was the tongue. Tumor growth patterns were evaluated in 52 cases, and 44 cases (84.6%) showed infiltrative growth patterns. Local recurrence was 26.7%, and distant metastasis was 4.4%. Because of the locally aggressive feature, it is important to diagnose LGMS with biopsy and to excise the tumor with an adequately wide margin.

Primary low-grade myofibroblastic sarcoma: A rare case report of this tumor in the orbit and literature review

Low-grade myofibroblastic sarcoma (LGMS) is an exceedingly rare, malignant tumor with myofibroblastic differentiation. It frequently occurs in the oral cavity and extremities, despite being classified as a distinct entity by the World Health Organization (WHO). Here, we report a rare case of orbital LGMS occurring in an 11-month-old baby with a 3.2 × 2.4 × 2.1 cm mass. LGMS was diagnosed based on the histological and immunohistochemical findings. Previous literature suggests that surgical resection with clear margins is an appropriate method for the treatment of LGMS, and combined adjuvant therapy (local radiotherapy with or without chemotherapy) can improve the prognosis, but further studies are needed.

Evaluation and Management of an Uncommon Tumor of the Larynx: A Case Report and Literature Review of Laryngeal Low-Grade Myofibroblastic Sarcoma

Low-grade myofibroblastic sarcoma (LGMS) of the larynx is an uncommon entity. These mesenchymal tumors of the larynx are rare and account for approximately 0.3% to 1.0% of all neoplasms at this site. We report a rare case of LGMS of the larynx that involved the larynx of a 63-year-old man with a history of hoarseness of voice. The patient was treated with total laryngectomy with partial pharyngectomy without any adjuvant treatment. Histopathologically, the tumor was composed of spindle cells that manifested variable cellular anaplasia and expressed smooth muscle actin (SMA). Our patient is disease-free two years after surgery. The authors emphasize the clinical and histopathological findings and treatment of this case with a literature review. This case is among the few reported cases of LGMS of the larynx. It enlightens the classical clinical findings, histopathology, differential diagnosis, and treatment. Surgical excision with negative margins requires no adjuvant therapy.

Low-grade myofibroblastic sarcoma: a case report of a child

Introduction: Myofibroblastic sarcomas are malignant tumors characterized by the increased proliferation of myofibroblasts; they are rare and have been recently discovered. Observation: A 14-year-old adolescent had a large lesion in the inside of her right mandible. The diagnosis, after a difficult histological analysis, was low-grade myofibrosarcoma. The patient was treated with non-interruptive hemimandibulectomy. Discussion: Low-grade myofibroblastic sarcoma is one of four types of myofibroblastic sarcomas recognized by the WHO in the 2001 classification. This classification allows us to determine a prognosis based on histological characteristics of the lesion. Conclusion: In all cases of low-grade myofibroblastic sarcoma, the preferred treatment is curative surgical resection; but still poses a problem in the prosthetic rehabilitation of oral lesion.

Low-grade myofibroblastic sarcoma arising in the tip of the tongue with intravascular invasion: A case report

Low-grade myofibroblastic sarcoma (LGMS) is a rare intermediate tumor, which rarely metastasizes and has myofibroblastic differentiation in various sites. It is particularly associated with the tongue in the head and neck region. The lack of any pathological features means it is difficult to make a conclusive diagnosis of LGMS. The immunohistochemical features and genomic rearrangements, including SS18-SSXs and MYH9-USP6s and the genetic mutations of cancer-associated genes, including APC, CTNNB1, EGFR, KRAS, PIK3CA and p53 were examined in a case of LGMS arising in the tip of the tongue. Immunohistochemically, the tumor cells were positive for alpha-smooth muscle actin and vimentin, as in previous reports. They demonstrated neither genomic rearrangements nor point mutations of cancer-associated genes. Although several tumor cells demonstrated intravascular invasion, the MIB-l labeling index of the cells was the same as the original lesion. To the best of our knowledge, this is the first case report of LGMS arising in the tip of the tongue with intravascular invasion.

Gingival Leiomyosarcoma in a Young Woman: Case report and literature review

Leiomyosarcoma (LMS) is a rare mesenchymal malignancy, of which 3-10% of cases occur in the head and neck region. We report a 22-year-old woman who was referred to the University Hospital of Siena, Italy, in 2016 with an ostensibly benign asymptomatic lump on the mandibular gingiva. The lesion grew rapidly, causing otalgia in the right ear. An excisional biopsy was performed and primary LMS was diagnosed histologically. Subsequently, the patient underwent radical re-excision of the perilesional mucosa, a partial bone resection and the extraction of four teeth. No recurrences or metastases were detectable at a 20-month follow-up. This report discusses the differential diagnosis of LMS with regards to other benign and malignant lesions and reviews the recent literature on primary and secondary oral LMS. Due to its innocuous clinical features-including its asymptomatic nature and presentation at a young age-this aggressive malignancy can go undetected; therefore, an early histopathological diagnosis is crucial.

Low-grade myofibroblastic sarcoma of the orbit: A case report and literature review

RATIONALE

Low-grade myofibroblastic sarcoma (LGMS) is a malignant lesion composed of myofibroblasts. It is an uncommon tumor of unknown etiology that mainly develops in the bone or soft tissue and is most often reported in the head and neck, particularly in the tongue and oral cavity.

PATIENT CONCERNS

A 2-year-old girl, previously well and with no significant medical history or family history of other diseases, presented with a 2-week painless swelling of the right orbit.

DIAGNOSES

Preoperative computed tomography (CT) revealed a large homogeneous enhanced mass, 21 × 13 mm in size, located on lateral wall of the right orbit with bone absorption. The mass was resected and histopathological examination revealed LGMS of the orbit.

INTERVENTIONS

On May 2016, she underwent surgery without the additional postoperative treatment.

OUTCOMES

The patient's postoperative course was uneventful, and was discharged on the 6th day after surgery. During a year follow-up period, there was no recurrence of the postoperative CT. The patient and her family were satisfied with the result of the surgery.

LESSONS

Based on clinical characteristics and postoperative CT, we considered the mass may be a benign tumor. We completely resected along the capsule without an extensive surgical margin. However, postoperative histopathology diagnose LGMS, which shows a strong potential for local recurrence and vascular invasion. So we should close observation of the patient's symptoms and sign. If the tumor has invaded adjacent tissues, we will use adjuvant chemotherapy or radiotherapy.

Indolent growth of low-grade myofibroblastic sarcoma of the cheek mimics benign lesions: A case report and literature review

Low-grade myofibroblastic sarcoma (LGMS) is a neoplasm of the soft tissue characterized by myofibroblastic differentiation. This type of tumor has been observed in various sites in the whole body, but frequently occurs in the head and neck region. It typically presents as a slow-growing painless mass, which is often mistaken for a benign lesion due to its indolent growth; however, LGMS is a malignant neoplasm. In the present study, a 43-year-old female presented with a 14-mm LGMS lesion in the buccal subcutaneous tissues of the buccinator muscle. The patient had initially noticed the lesion 2-months prior to presenting at the hospital. Following biopsy, the tumor was surgically resected and no recurrence or metastasis was observed during a follow-up time of 2 years. To the best of our knowledge, this case is the first report of LGMS located in the buccal subcutaneous tissue of the buccinator muscle. The present study a literature review of 55 cases of this tumor type in the head and neck region was conducted, revealing that the indolent growth of these lesions may contribute to a delay in diagnosis. The average time between the onset of clinical symptoms and hospital admission is 3.9 months, and this form of tumor is frequently misdiagnosed as a benign lesion. Therefore, the present study suggests that an incisional biopsy may be performed to rule out LGMS when clinicians encounter patients with the aforementioned indolent lesions anywhere in the body. In addition, the avoidance of radiotherapy is recommended following resection of the LGMS tumor, as it may induce LGMS recurrence.

Low Grade Myofibroblastic Sarcoma Occurred in the Scalp

Low-grade myofibroblastic sarcoma (LGMS) is a rare sarcoma with myofibroblastic differentiation. LGMS has a propensity for local recurrence and is associated with a low risk of metastatic spread. A 26-year-old man presented with a 12-month history of a slow growing palpable hard mass in the right parietal scalp. Enhanced CT scan of head showed a 3×4 cm sized well-defined and heterogeneously enhancing scalp mass. The patient underwent excision of the tumor. The histological and immunohistochemical features were consistent with a LGMS. We performed re-operation for remnant tumor removal after diagnosis. After 14 months of surgery, the patient was well-being state.

LOW-GRADE MYOFIBROBLASTIC SARCOMA OF THE LARYNX: CASE REPORT AND REVIEW OF LITERATURE

Low-grade myofibroblastic sarcoma (LGMS) is a very rare, atypical myofibroblastic tumor with fibromatosis-like features with predilection mostly in head and neck region. LGMS occurs primarily in adult patients with a slight male predominance. Only few cases of LGMS affecting the larynx have been reported in literature to this date. We describe a case of low-grade myofibroblastic sarcoma of the larynx in a 40-year-old male patient. The clinicopathological characteristics, immunohistochemical findings and treatment are discussed.

Low-grade myofibroblastic sarcomas of the maxilla

Low-grade myofibroblastic sarcoma (LGMS) is a distinct mesenchymal myofibroblastic malignancy. The tumor may occur at a variety of sites, but is particularly associated with the head and neck. Of the two maxillary sarcomas that were analyzed in the present study, one was misdiagnosed as an inflammatory myofibroblastic tumor during pre-operative excision biopsy, and later presented with a different immunophenotype upon recurrence. Representative paraffin blocks from formalin-fixed tissues were selected from each patient and designated as case 1 and case 2. Immunohistochemical studies were performed on 3-μm thick sections using primary antibodies against α-smooth muscle actin (α-SMA), muscle-specific actin (MSA), desmin, vimentin, calponin, h-caldesmon, fibronectin, cytokeratin, cluster of differentiation 34 (CD34), S-100 protein, anaplastic lymphoma kinase (ALK), epithelial membrane antigen (EMA) and Ki-67. Immunohistochemistry was performed using the streptavidin-biotin-peroxidase complex method. The tumor cells from the two maxillary LGMSs, including the recurrent lesion, were positive for vimentin and fibronectin, and negative for S-100 protein, CD34, EMA, h-caldesmon, ALK, MSA and calponin. The tumor cells from case 1 demonstrated positive staining for α-SMA protein and negative staining for desmin. By contrast, the tumor cells from the primary lesion in case 2 presented with negative staining for α-SMA and positive staining for desmin, while the cells of the recurrent lesion were α-SMA-positive and desmin-negative. The present study concluded that cases of LGMS with immunoprofile alterations are predictive of relatively poor prognoses.

Epidermal nevus and ameloblastoma: a rare association

Epidermal nevi are clinical manifestations of a malformation affecting the embryonic ectoderm. They appear as linear verrucous lesions and are more often located in the skin of the trunk or the extremities. Rarely, verrucous lesions affect the oral mucosa. Epidermal nevi can be a component of epidermal nevus syndrome (ENS), which is characterized by malformations involving several organs, such as the central nervous system. ENS is rarely associated with other solid tumors. We present the case of a patient affected by ENS who developed maxillary and mandibular ameloblastomas. Epidermal nevi were located in the left middle and lower third of the face and in the left cervical region, whereas the ameloblastomas arose within the left maxillary mucosa and within the left mandibular ramus. Features of the syndrome are described and the relevant literature is reviewed.

Low-grade myofibroblastic sarcoma of the palate

Low-grade myofibroblastic sarcoma (LGMS) is a rare, malignant tumor with myofibroblastic differentiation. Despite it being classified as a distinct entity by the World Health Organization, a few cases were reported in the oral and maxillofacial region. Here, a LGMS developed on the palate of a 73-year-old man who presented with a 1-cm tumor on the posterior border of the palate. Based on the histological and immunohistochemical features, a diagnosis of LGMS was established. The tumor was resected, and no recurrence was observed over 2 years. Although the tongue is the most preferred site for LGMS, it may occur in any region of the oral cavity.

Ultrastructurally confirmed myofibrosarcoma: a series of 10 new cases, with a discussion on diagnostic criteria

Some view ultrastructure as key to myofibrosarcoma diagnosis, whereas others argue that electron microscopy is too little used in contemporary practice to be considered an important diagnostic tool. These views are discussed in the context of 10 ultrastructurally confirmed cases of myofibrosarcoma, some occurring at rare sites such as skin and penis. Patient age ranged from 21 to 83 years, with a 6:4 male to female ratio. Size ranged from 2 to 7.5 cm and all had infiltrative margins. Histologically, all consisted of variably cellular fascicles of spindle cells with mild to moderately pleomorphic nuclei, small punctate nucleoli, and eosinophilic cytoplasm. All cases showed α-smooth muscle actin positivity and 2 showed very focal weak positivity for desmin. Ultrastructurally, the tumor cells contained rough endoplasmic reticulum, mainly peripheral smooth-muscle myofilaments, and fibronectin fibrils or fibronexus junctions at the cell surface. The most confident diagnosis of myofibrosarcoma is provided by ultrastructural examination. However, given the right histological appearance, use of a panel of antibodies that includes α-smooth muscle actin, desmin, and h-caldesmon, serves as an acceptable practical way of diagnosing myofibrosarcoma.

Differential diagnosis of inflammatory myofibroblastic tumour and low-grade myofibroblastic sarcoma: two case reports with a literature review

Inflammatory myofibroblastic tumour (IMT) and low-grade myofibroblastic sarcoma (LGMS) have similar morpho logical and immunophenotypic features, but LGMS is more malignant than IMT and the treatment requires a wider surgical margin plus post-operative chemotherapy or radiotherapy. To date, only 28 cases of IMT and two cases of LGMS have been reported in the laryngopharynx. Recent studies have suggested that anaplastic lymphoma kinase (ALK) and cytokeratin are important markers for differentiating between the two tumours. Here, two cases involving different myofibroblastic tumours of the larynx are reported. Based on the histological and immunohistochemical results, case 1 was diagnosed as IMT involving the right arytenoepiglottic fold, while case 2 was diagnosed as LGMS involving the epiglottic-glossal surface. There was no recurrence or metastasis in either case after post-operative follow-up (12 and 14 months, respectively). It is difficult to distinguish IMT from LGMS; both morphological and immunohistological analyses are required.

Low-grade myofibroblastic sarcoma of the gingiva

Low-grade myofibroblastic sarcoma is a malignant tumour from myofibroblasts, which has only recently become clearly defined. It represents a rare entity developing in the soft tissues of the head and neck. About 20 cases have been reported in the oral cavity, especially in the tongue and bone, while gingiva as the primary site has been described only once to date. Diagnostic methods include histology and immunohistochemistry. The present report concerns a case of a 37-year-old man who presented with a persistent gingival ulcerated swelling that was interpreted for a long time as a gingival epulis. A low-grade myofibrosarcoma was diagnosed and the patient underwent a segmental osteotomy of the mandibular symphisys for complete excision. There was no sign of recurrence or metastatic disease during the 18-month postoperative period.

[A rare tumour of the auricle]

We report on a patient suffering from a mesenchymal tumour located at the antihelix. Histopathology of the tissue specimens derived from this lesion reported a myofibroblastic sarcoma, a rare tumour entity with a slight predominance of occurrence in the area of the head and neck. Grading of these tumours can be challenging since benign as well as malign phenotypes have been described. Therefore, beside complete resection of the lesion additional radiotherapy should be discussed individually.