Myofibroblastic sarcoma of the nasal cavity and paranasal sinus: a clinicopathologic study of 6 cases and review of the literature

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.

Sinonasal nodular fasciitis: report of a case with USP6 rearrangement

Nodular fasciitis (NF) is a benign myofibroblastic proliferation characterized by rapid growth, a self-limiting course, and USP6 gene rearrangement. Although it can arise in the head and neck region, very few cases of NF involving the sinonasal tract have been reported to date. Herein we report a case of NF involving the nasal cavity presenting as a polypoid well-defined mass causing obstructive symptoms in a male with a history of multiple local surgeries. Although the mass had an unusual clinical presentation, the histopathologic and immunohistochemical findings were consistent with NF. Fluorescent in situ hybridization performed with break-apart probes flanking the USP6 locus on chromosome 17p13 revealed the presence of USP6 gene rearrangement. The patient remained free of disease 124 months after surgical treatment. Considering its remarkably benign behavior despite its alarming clinical and histologic features, the distinction of NF from sinonasal malignant tumors is essential.

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.

Case Report: Immunotherapy for low-grade myofibroblastic sarcoma of the pharynx

Low-grade myofibroblastic sarcoma (LGMS) characterized by the increased proliferation of myofibroblasts is a rare type of malignant myofibroblastic tumor that frequently occurs in the head and neck region. Presently, there is no consensus regarding the treatment of LGMS. Here, we report a rare case of LGMS of the pharynx in a 40-year-old male admitted to our hospital. The patient underwent resection for a right metastatic lesion and parapharyngeal mass. However, he had recurrence and multiple metastases without a surgical indication. Then the patient received the treatment of anlotinib plus pembrolizumab for 4 cycles, and there was a partial response (PR) to the treatment. Due to the adverse reaction of anlotinib, the patient subsequently received monotherapy of pembrolizumab for 22 cycles and achieved a complete response (CR). As the first case report of the immunotherapy for LGMS, our study highlights that this strategy may be of great significance to the treatment of LGMS.

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.

S-100 Immuno-Positive Low Grade Myofibroblastic Sarcoma of Nasal Cavity: A Rare Case Presentation and Review of Literature

Introduction

Myofibroblastic neoplasms comprise a spectrum of benign/malignant neoplasms. Only low-grade malignant forms have been reproducibly characterized as a diagnostic entity in the WHO classification. Low grade myofibroblastic sarcoma (LGMFS) confined to the nasal cavity is extremely rare.

Objective

To review previously reported cases of nasal cavity LGMFS and provide a better insight regarding its clinical and immunohistochemical features.

Data synthesis

A review was performed involving two databases (PubMed and Google Scholar). Four cases of nasal cavity LGMFS were included. The lesion showed no gender or nasal-side predilection. All cases underwent wide excision. None showed distant metastasis while half recurred locally. Histologically, mitotic rate ranged from 1 to 3/10 high-power-field (HPF) and none exhibited spontaneous necrosis. Immuno-expression of calponin, smooth muscle actin (SMA) and vimentin were seen in either all four or three-fourth of cases. Diffuse S-100 expression was a unique finding in present case and not reported previously, that caused a diagnostic dilemma with schwannomas.

Conclusion

LGMFS of nasal cavity is extremely rare. A wide resection is the primary treatment of choice. Adjuvant therapies (chemotherapy or radiotherapy) are of uncertain significance. Distant metastasis is rather unusual. Calponin, SMA and vimentin are highly sensitive immuno-markers. Diffuse S-100 expression is a possible finding. Mitotic rate < 6/10 HPF and absence of spontaneous necrosis are characteristic indolent features differentiating from high grade lesions. Trifecta of clinical and morphological features plus immunohistological phenotype, are sufficient for a definitive diagnosis. Electron microscopy is the most definitive confirmation test, however, should be reserved only for equivocal/atypical immunostaining pattern.

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.

High-grade myofibroblastic sarcoma of the pleura: A case report and literature review

High‐grade myofibroblastic sarcoma (HGMS) is a rare cancer that has high recurrence and metastatic rates. Here, we report the first case of HGMS originating from the pleura. Based on the findings of pleural biopsy, pathological examination and immunohistochemical staining, grade III myofibroblastic sarcoma (MS) was diagnosed. The patient underwent eight cycles of chemotherapy (epirubicin and ifosfamide), followed by radiotherapy. As of May 2020, the patient had been followed for six months and no tumor progression had occurred.

Key points

This is the first report of high‐grade myofibroblastic sarcoma originating from the pleura. The patient was treated via nonsurgical strategies, including chemotherapy and radiotherapy.

Is there a role for chemotherapy and radiation in the treatment of patients with low-grade myofibroblastic sarcoma?

PURPOSE

Low-grade myofibroblastic sarcoma (LGMS) is a rare entity with a predilection for the head and neck. There are still no optimal treatment strategies for patients with LGMS. We retrospectively investigated the efficacies of chemotherapy and radiation treatment for patients with LGMS.

METHODS/PATIENTS

We obtained data from the Surveillance, Epidemiology, and End Result (SEER) database for 96 patients diagnosed with LGMS between 2001 and 2015. We used Kaplan-Meier curves and log-rank tests to estimate overall survival (OS) and Cox proportional hazard regression to identify prognostic factors.

RESULTS

The median age of the patients was 55.0 years. Twenty-two of the patients had LGMS in the head and neck region. Of the 96 patients, 86 (89.6%) received surgical treatment, 28 (29.2%) received radiation treatment, and 20 (10.4%) received chemotherapy. The mean OS was 125.2 [95% confidence interval (CI) 106.3-144.2] months. The 1, 3, 5, and 10-year OS rates were 88%, 77%, 70%, and 59%, respectively. Age greater than 60 years, positive nodal status, and no surgical treatment were independent prognostic factors for patients with LGMS, whereas chemotherapy and radiation treatment were not.

CONCLUSIONS

Surgical resection is the most effective therapy for LGMS. Chemotherapy and radiation had limited effects on survival improvement for patients with LGMS. Therefore, chemotherapy and/or radiation therapy should not be routinely performed in LGMS, especially for those with negative margins after surgery.

Sinonasal glomangiopericytoma: A clinicopathologic study

Sinonasal glomangiopericytoma (SNGP) is a neoplasm arising in the nasal cavity and paranasal sinuses that shows perivascular myoid differentiation. The diagnosis of SNGP may be diagnostically challenging due to a large number of potential mimics. In the present study, we sought to characterize the histological and molecular features of six cases of SNGP found in prior surgical pathology records over a 15-year period. The average age at diagnosis was 48.5 years (range: 31-78 years), and the male-to-female ratio was 1:1. Imaging studies in all six cases demonstrated avidly enhancing, lobulated soft tissue masses in the nasal cavity, extending into the sinuses and nasopharynx. Histologically, the tumors were unencapsulated and composed of a proliferation of closely packed, bland, and uniform spindle cells growing deep to an intact surface respiratory epithelium. The cells were separated by a distinctive vascular network ranging from capillaries to large vascular spaces. All cases demonstrated strong positivity for smooth muscle actin, cyclin D1, CD99, and β-catenin (100%). Targeted sequencing revealed recurrent CTNNB1 missense mutations in all cases tested. Additionally, TLE1 was positive in all cases which has not been previously reported. No tested cases harbored SS18 translocations. We found that while no single marker resolves immunohistochemical overlap between SNGP and its histologic mimics, an extended immunohistochemical panel that includes β-catenin, cyclin D1, STAT6, smooth muscle actin, pan-cytokeratin cocktails, S100, and SOX10 helps to support the diagnosis of SNGP in diagnostically challenging cases without the need for molecular studies.

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.

High-grade myofibroblastic sarcoma in the liver: A case report

Only two cases of myofibroblastic sarcoma in the liver have been reported in the literature. Here, we report the case of a male patient with high-grade myofibroblastic sarcoma mimicking echinococcosis in the liver. The 25-year-old male patient complained of right upper quadrant swelling pain for one week and was initially diagnosed with echinococcosis. He was then scheduled for an exploratory laparotomy. During the operation, a huge mass exceeding 16 cm in diameter was found to occupy nearly the entire right trisegment of the liver, with a clear boundary and a round shape, and the mass was resected by right hepatic trisegmentectomy. Immunohistochemical staining revealed that the tumor tissue was positive for desmin, α-smooth muscle actin, CD56, and vimentin and negative for ALK-1, myogenin, calponin, β-catenin, S100, and glypican-3, with a Ki-67 (MIB-1) index of approximately 20%. Based on the histological manifestations and immunohistochemical staining, a diagnosis of myofibroblastic sarcoma was established. The postoperative recovery was uneventful. There was no evidence of recurrence or metastasis through the last follow-up, 6 mo after surgery, despite a lack of postoperative chemotherapy or radiotherapy. To the best of our knowledge, the present case is the first reported case of high-grade myofibroblastic sarcoma in the liver, and it is also the first reported case in a male patient.

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 in the Mandibular Canal: A Case Report

Low-grade myofibroblastic sarcoma (LGMS) represents an atypical myofibroblastic tumor characterized by a diffusely infiltrating pattern of spindle-shaped tumor cells. It was classified as a distinct soft tissue tumor by the World Health Organization in 2002. LGMS occurs mostly in adult patients and has a predilection for the head and neck region. So far, only a few cases of LGMS located in the mandible have been reported. Aggressive surgical resection with clear margins is the primary treatment for LGMS. Because of its rarity, reports of radiation therapy are limited, and the therapeutic effect is still controversial. We present the case of an 8-year-old girl with LGMS of the mandibular canal to highlight the clinical features and rarity and to improve the understanding of the therapeutic effect of radiotherapy on LGMS.

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.

Cardiac metastasis of a low-grade myofibroblastic sarcoma

We aim to present a rare case of low-grade myofibroblastic sarcoma arising in the inguinal region accompanied by cardiac metastasis. A 36-year-old male patient suffering from recurrent inguinal swelling was operated on and the initial histopathological evaluation mistakenly diagnosed the condition as benign. During follow-up, a recurrence of mass was detected in the same region and a pathological examination revealed a low-grade myofibroblastic sarcoma. Cardiac metastasis was diagnosed shortly before rapid disease progression and death. The learning points relevant to this case are as follows: (1) Echocardiographic screening in patients with noncardiac myofibroblastic sarcomas may be helpful in the detection of silent metastasis. (2) Low-grade myofibroblastic sarcomas in the inguinal region may be misdiagnosed as benign after enucleation. Thus, rigorous histopathological examination of myofibroblastic sarcomas is crucial. (3) According to our knowledge, this is the first report of a low-grade myofibroblastic sarcoma to have a potential for cardiac metastasis with potentially fatal course.

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.

Low-grade myofibroblastic sarcoma of the maxillary region in a dog

A subcutaneous tumour was identified in the maxillary region of a 14-year-old mixed breed dog. This tumour had grown rapidly over 2 weeks. Microscopically, the tumour had ill-defined borders and was composed of bundles and whorls of atypical spindle cells accompanied by abundant collagen fibres. Immunohistochemically, neoplastic cells were immunoreactive for vimentin, α-smooth muscle actin and calponin and negative for S100 protein, von Willebrand factor, desmin and smoothelin. These results suggested that the neoplastic cells were derived from myofibroblasts and that the tumour was a low-grade myofibroblastic sarcoma.

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.

[Myofibroblastic sarcoma of the larynx : a case report and review]

BACKGROUND

Myofibroblastic sarcomas or myofibrosarcoma, are extremely rare malignant neoplasms of myofibroblasts. They are characterized by the pattern of cells and special immunohistochemical markers such as vimentin, desmin and alpha-smooth-muscle actin.

PATIENT AND METHOD

The case of a patient with a history of frequently relapsing papillomas of the larynx is reported. Chronic laryngitis with focal low-grade dysplasia of the squamous epithelium was diagnosed approximately 1 year after the first treatment of the papillomas. After approximately 2 years the pathologist diagnosed the rare myofibroblastic sarcoma of the larynx. The patient underwent laryngectomy due to the spread of the tumor with a bilateral selective neck dissection. The patient is at present still free of recurrence and metastases.

RESULTS AND CONCLUSIONS

There is a great danger of misjudging a myofibroblastic sarcoma as an inflammatory myofibroblastic tumor and consequently to delay the urgently needed treatment. Therefore, an overview of the present state of knowledge about diagnosis and treatment of myofibroblastic sarcomas will be given based on this case report.

Collagenous myofibroblastic tumor of the mandible: case report of a unique locally aggressive neoplasm

We report a locally aggressive collagenous myofibroblastic neoplasm of the mandible in an 18-year-old male. Clinically, the lesion presented with rapid growth and irregular mandibular bone destruction. Grossly, the tumor was 10 cm in greatest dimension, light-tan, firm, and involving the posterior one-thirds of the body and inferior half of the left mandibular ramus. Histologically, the lesion was composed of a loose spindle cell proliferation interspersed with periodic dense bands of collagen. The spindle cells reacted positively to smooth muscle actin, calponin, and focally to desmin and were negative for S-100, pan-cytokeratin, CD99, CD34 and caldesmon, supporting myofibroblastic derivation. At our 4 year follow-up, the patient remained free of local recurrence and surgery related complications. The clinicopathologic findings and the differential diagnosis of this lesion is presented and discussed.

Low-grade myofibroblastic sarcoma of the oral cavity

Two cases of low-grade myofibroblastic sarcoma (LGMS) are presented: one of lateral tongue, the other of lower buccal vestibule. LGMS represents a distinct atypical myofibroblastic tumor that occurs in several sites, primarily within the head and neck regions. A painless, enlarging mass is the most common clinical presentation, but a definitive diagnosis requires both histopathological and immunohistochemical analyses. Histologically, LGMS commonly presents as a cellular lesion composed of spindle-shaped tumor cells arranged primarily in fascicles with a diffusely infiltrative pattern. Immunohistochemically, LGMS shows positive staining for at least one myogenic marker, such as desmin, and muscle actin.

Myofibroblastic sarcoma vs nodular fasciitis: a comparative study of chromosomal imbalances

We investigated the molecular cytogenetic features in myofibroblastic sarcoma (MS) to gain insight into the nature of the controversial entity. DNA copy number changes were analyzed by comparative genomic hybridization in 29 cases of MS and 5 cases of nodular fasciitis. The characteristic chromosomal imbalances in MS were gains at 1p11 --> p36.3 (19/29 [66%]), 12p12.2 --> p13.2 (13/29 [45%]), 5p13.2 --> p15.3 (9/29 [31%]), and chromosome 22 (8/29 [28%]) and loss at 15q25 --> q26.2 (7/29 [24%]). In contrast, only 1 of 5 cases of nodular fasciitis showed genetic aberrations. The average number of aberrations in nodular fasciitis (0.4) was significantly lower than that in MS (5.4). Thus, MS displayed complex DNA copy number changes and shared no range of common chromosomal abnormality with nodular fasciitis, indicating that distinct genetic pathways may be involved in the development of these entities.

Myofibroblastic sarcoma of the base of tongue. Case report and review of the literature

BACKGROUND

Mesenchymal malignancies with myofibroblastic differentiation exhibit a spectrum from low-grade myofibroblastic sarcoma mimicking fibromatosis to pleomorphic high-grade sarcoma. Low-grade myofibroblastic sarcoma shows a wide anatomic distribution with a predilection for the head-and-neck region; however, intermediate- and high-grade myofibroblastic sarcomas in this localization are exceptional.

CASE REPORT

A 56-year-old woman with intermediate-grade myofibroblastic sarcoma of the base of tongue is presented. She was treated with surgical excision, but computed tomography proved local residual tumor. Reexcision and chemotherapy were refused by the patient. Irradiation was given to a total dose of 66 Gy.

RESULT

50 months after completion of radiotherapy, the patient is in good health without any evidence of disease. According to the review of the literature, base of tongue as the primary site of myofibroblastic sarcoma has not been published so far.

CONCLUSION

Similarly to the low-grade form, intermediate- and high-grade myofibroblastic sarcomas may also occur in the head-and-neck region. In case of incomplete excision, radiotherapy may be an effective treatment.

A Case of Two Different Tumors in the Heart of a Dog

A 9-year-old, spayed, female Maremmano shepherd had a bilateral mastectomy for multiple mammary adenocarcinomas 2 years previous and was referred to the Cardiology Service of the School of Veterinary Medicine of Milan after an acute episode of cardiogenic collapse. Because of severe cardiovascular symptoms and poor prognosis, the dog was euthanized. Necropsy examination revealed the presence of multiple firm grayish neoplastic nodules in the myocardium of the left ventricle and scattered in the pulmonary parenchyma. Neoplastic nodules were also detected in the spleen, pancreas, liver, kidneys, and omentum. Histological examination revealed the coexistence of tubular adenocarcinoma and an undifferentiated sarcoma in the myocardium. Immunohistochemical staining of the sarcoma cells was negative for cytokeratin, desmin, and smooth muscle myosin, thus excluding their epithelial or myoepithelial origin, as well as an origin from smooth muscles cells. These findings, together with the coexpression of vimentin and α-smooth muscle actin, suggested that the sarcoma was derived from myofibroblasts. To the authors' knowledge, this is the first report describing cardiac sarcoma of presumptive myofibroblastic origin in a dog with simultaneous occurrence of cardiac metastasis of mammary gland adenocarcinoma.