Intramuscular myxoma--a clinicopathological study of twenty-three cases

Genetic characterization of intramuscular myxomas

Introduction: Intramuscular myxomas are benign tumors that are challenging to diagnose, especially on core needle biopsies. Acquired chromosomal aberrations and pathogenic variants in codon 201 or codon 227 in GNAS complex locus gene (GNAS) have been reported in these tumors. Here we present our genetic findings in a series of 22 intramuscular myxomas. Materials and methods: The tumors were investigated for the presence of acquired chromosomal aberrations using G-banding and karyotyping. Pathogenic variants in codon 201 or codon 227 of GNAS were assessed using direct cycle Sanger sequencing and Ion AmpliSeq Cancer Hotspot Panel v2 methodologies. Results: Eleven tumors carried chromosomal abnormalities. Six tumors had numerical, four had structural, and one had both numerical and structural chromosomal aberrations. Gains of chromosomes 7 and 8 were the most common abnormalities being found in five and four tumors respectively. Pathogenic variants in GNAS were detected in 19 myxomas (86%) with both methodologies. The detected pathogenic variants were p.R201H in nine cases (seven with abnormal and two with normal karyotypes), p.R201C in five cases, all with normal karyotypes, p.R201S in three cases (two with abnormal and one with normal karyotype), p.R201G in one case with a normal karyotype, and p.Q227E in one case with a normal karyotype. Conclusion: Firstly, our data indicate a possible association between chromosomal abnormalities and GNAS pathogenic variants in intramuscular myxomas. Secondly, the presence of the rare pathogenic variants R201S, p.R201G and p.Q227E in 26% (5 out of 19) of myxomas with GNAS pathogenic variants shows that methodologies designed to detect only the common "hotspot" of p.R201C and p.R201H will give false negative results. Finally, a comparison between Ion AmpliSeq Cancer Hotspot Panel v2 and direct cycle Sanger sequencing showed that direct cycle Sanger sequencing provides a quick, reliable, and relatively cheap method to detect GNAS pathogenic variants, matching even the most cutting-edge sequencing methods.

Lumbar paraspinal intramuscular myxoma: A case report

Background:

With an estimated incidence of about 1 case/million patients, paravertebral intramuscular myxomas represent a rare cause of lumbar pain. Rather, they typically occur in the heart and in bone tissues.

Case Description:

A 64-year-old female presented with a protracted course of nocturnal lumbar pain that radiated to the anterior aspect of the right thigh accompanied by numbness. She reported a slow-growing right paramedian lumbar mass in the previous months. The magnetic resonance (MR) showed a right lumbar paravertebral intramuscular mass at the L3 level (i.e., 70 × 50 mm) that had well-defined margins, and markedly enhanced with gadolinium. Following gross total “en bloc” tumor resection, the patient fully recovered. Pathologically, the myofibroblastic lesion proved to be an intramuscular myxoma without malignant changes.

Conclusion:

A 64-year-old female presented with a slow-growing MR-documented right paramedian lumbar L3 mass responsible for proximal right-thigh numbness. Following “en bloc” gross total removal of the benign intramuscular myxoma, the patient was asymptomatic.

Diagnostic and Therapeutic Pathways of Intramuscular Myxoma

Intramuscular myxomas (IMMs) are benign tumors. Evidence regarding diagnostic and therapeutic pathways is rare, and guidelines do not exist due to their low incidence. The aim of this study was a retrospective analysis at a university cancer center and the interdisciplinary re-evaluation of the individual diagnostic and therapeutic procedures. Overall, 38 patients were included in the study. IMMs occurred mostly in middle-aged women. At the time of first consultation, 57.9% had few symptoms or were asymptomatic. In 92.1% of the cases, the tumor was localized in the extremities. The lower extremity was affected in 73.7%. The average size of IMMs was 5.0 cm. The proximally located tumors in the gluteus, thighs, and upper arms were significantly larger (p = 0.02) than the distally-located tumors in the forearms and lower legs. An MRI was performed in 97.4%. Based on imaging, an IMM was suspected in 5.6% by radiologists and in 54.1% by musculoskeletal surgeons. An incision biopsy was performed in 68.4% and led in 100.0% to the right histopathological diagnosis. In total, 89.5% of IMMs were resected. Postoperative complications requiring revision occurred in 8.8%. Recurrences or degenerations of IMMs were not reported in any of these cases.

Incidental Intercostal Intramuscular Myxoma With Fibrous Dysplasia in a Patient With Mazabraud’s and McCune Albright Syndromes

Intramuscular myxoma is a rare entity that may present as single or multiple lesions in patients with Mazabraud’s syndrome and is characterized by intramuscular myxomas with fibrous dysplasia. Though intramuscular myxomas occur in large muscle groups, they can very rarely occur in the chest wall. We present the case of a 41-year-old woman with an incidentally discovered intercostal mass on magnetic resonance cholangiopancreatography (MRCP). Repeat MRI demonstrated a lobulated, T2-hyperintense intercostal lesion and demonstrated adjacent fibrous dysplasia of the ribs, consistent with the patient’s history of Mazabraud's and McCune Albright syndromes. Histopathological exam following surgical resection confirmed a diagnosis of intramuscular myxoma without the presence of sarcomatous changes. Though small, slow-growing intramuscular myxomas may be observed with conservative management in the absence of significant symptoms, surgical resection is warranted to prevent complications such as osseous erosion or nerve impingement.

OUP accepted manuscript

Intramuscular myxoma (IM) is a rare benign tumour. It may occur at any age but most commonly occurs among older women. The preoperative diagnosis of IM is complicated. The diagnosis can only be definitively established by histopathological examination. The treatment of choice is radical surgical excision. We report a case of a 41-year-old woman with an IM of the biceps brachii muscle.

Surgical Treatment of Intramuscular Myxoma

PURPOSE

Intramuscular myxoma (IM) is a rare benign myxoid tumor that may be challenging to differentiate from sarcoma in small amounts of biopsied material. Although IM appears to be well-circumscribed macroscopically, it infiltrates the adjacent edematous muscle microscopically. The recommended treatment is resection, but there is controversy with regard to the appropriate surgical margin. This study aimed to clarify which surgical procedure that should be applied when the preoperative diagnosis is IM and how to manage treatment if the postoperative diagnosis turns out to be a sarcoma.

METHODS

We retrospectively examined 55 IM patients treated from January 1982 to December 2014. Patient characteristics, tumor location, tumor size, radiograph, preoperative and postoperative pathological reports, surgical techniques, treatment outcome, and complications were reviewed. The patients were followed up on for at least 5 years. All patients were confirmed not to have Mazabraud syndrome.

RESULTS

In the 55 IM patients examined, the mean patient age was 48 years and most were female. The most common tumor locations were in the muscles of the thighs (47%) and buttocks (20%). The mean tumor diameter was 5 cm. Wide resection and marginal resection were performed in 24 and 31 patients, respectively. The mean follow-up duration was 19 years. No local recurrence, malignant transformation, or complications were observed.

CONCLUSIONS

Marginal resection is suitable in patients whose preoperative diagnosis is IM, as it is able to prevent local recurrence and allows for the preservation of muscle and muscle fascia. If the postoperative diagnosis turns out to be myxoid sarcoma, minimum surgical contamination makes additional wide resection less invasive.

Intramuscular myxoma of the longus colli mistaken for a cervical rootlet schwannoma

An 86-year-old woman was referred to the otolaryngology clinic for a 1-year history of a painless, slow-growing neck mass. Physical examination showed a fixed, immobile right level II neck mass with normal vocal cord movement. MRI demonstrated a lobulated mass laterally displacing the carotid vessels, consistent with a schwannoma. Despite the pathognomonic radiographic findings for schwannoma, core needle biopsy of the mass was consistent with intramuscular myxoma (IM), which rarely presents in the head and neck region. After multiple years of slow growth with bulging into the pharynx, the patient ultimately underwent surgery to reduce the risk of airway compromise. The location of this IM together with its unusual imaging appearance is a unique finding in the head and neck and adds to the differential diagnoses for neck masses displacing the carotid sheath.

Diagnostic value of ultrasonography and other imaging examinations in patients with intramuscular myxoma: A case series and literature review

Intramuscular myxoma (IM) is a rare benign soft tumor of mesenchymal origin. Most IMs are located in the large skeletal muscles, and they are typically painless slow-growing masses that are detected incidentally. Surgical excision of IM usually has a good prognosis. Because of its rarity, diagnosing IM via imaging modalities such as ultrasonography (US), computed tomography, positron emission tomography/computed tomography, and magnetic resonance imaging (MRI) can be challenging. Relevant literature and cases were selected as per the inclusion and exclusion criteria. Characteristic imaging findings include a well-defined, ovoid mass with regular morphology and an orientation whereby the long axis is aligned with the course of muscle fibers. In US, IMs exhibit solid cystic mixed echo without obvious blood flow signal. However, MRI reveals hypointensity on T1-weighted images and hyperintensity on T2-weighted images with mild and patchy enhancement. In cases of suspected or potential IM, US and MRI can provide excellent resolution at a reasonable cost. This report aims to improve the recognition rate of IM. Herein, we review imaging characteristics that can contribute to the differential diagnosis of IM.

Oral intramuscular myxoma: case report and brief review of the literature

OBJECTIVE

Myxomas are rare benign mesenchymal soft tissue tumors that seldom affect the head and neck area. The present report describes a rare case of intramuscular myxoma of the oral cavity and briefly reviews the literature regarding the occurrence of these lesions in the maxillofacial area.

STUDY DESIGN

A 59-year-old patient was referred for the development of a slow-growing tumefaction in the right buccal mucosa in the previous 12 months. Magnetic resonance imaging was performed to characterize the lesion's dimensions and its relationship with the surrounding structures, and it revealed intramuscular localization in correspondence with the medial pterygoid muscle. Incisional biopsy was carried out to aid in the final diagnosis.

RESULTS

Histology revealed the presence of an intramuscular myxoma, characterized by discontinuous margins and locally infiltrating muscular fibers. A second surgery was performed to totally remove the lesion. Follow-up at 6 months did not show any signs of recurrence. A literature search was performed to retrieve data on the incidence of oral intramuscular myxomas.

CONCLUSIONS

To the best of our knowledge, this is the first case of intramuscular myxoma of the medial pterygoid muscle reported in the literature. Although rarely encountered, intramuscular myxomas should be considered when performing differential diagnoses of soft tissue masses at the level of the masticatory muscles.

Multiple paraspinal intramuscular myxomas: case report

Intramuscular myxomas (IMMs) are rare benign tumors of mesenchymal origin that are most often located in large skeletal muscles, particularly of the thigh. They have also been reported within the paraspinal musculature and should be considered in the differential diagnosis of a paraspinal mass. These lesions can cause neurological symptoms due to mass effect. This is a report of a 52-year-old man with multiple paraspinal tumors that exhibited concerning growth on serial imaging studies. To the authors' knowledge, this represents the first report of a patient with multiple paraspinal myxomas. CT-guided biopsy followed by surgical excision of the largest mass was performed. Histopathological analysis was consistent with an IMM. Patients with multiple IMMs often have an underlying genetic syndrome such as Mazabraud syndrome, McCune-Albright syndrome, or Carney complex. Despite variable growth patterns and associations with genetic syndromes, multiple IMMs have had no documented cases of malignant transformation into myxoid sarcoma; therefore, surgical excision should be considered based on a patient's individual symptoms.

A case of a myxoma within the obturator externus muscle

Intramuscular myxomas (IM) are rare benign tumors of mesenchymal origin. These tumors have a high myxoid content and a nonspecific radiologic appearance. Here we describe the case of a patient with an IM in an infrequent location; within the obturator externus muscle. A singular approach was utilized for the resection of this tumor in such rare location.

Despite IM being benign tumors, patients may require a surgical excision due to the difficulty of differentiating these tumors, with unreliable imaging features, from other myxoid soft tissue masses.

Mazabraud's Syndrome: A Case Report and Up-To-Date Literature Review

OBJECTIVE

Mazabraud's syndrome is a rare form of bone fibrous dysplasia associated with intramuscular myxomas. Fibrous dysplasia, is generally localized to pelvis and femur and it results in a fragile bone with deformities, pain, pathological fractures and functional impairment. Intramuscular myxomas, are rare benign mesenchymal neoplasms that exceptionally may evolve to malignant forms.

METHODS

This case report describes a 66-year-old woman with Mazabraud's Syndrome (MS), characterized both by monostotic right femur fibrous dysplasia and by a solitary intramuscular myxoma at the right quadriceps muscle, that underwent a long-term treatment (4 years) with intravenous zoledronic acid.

RESULTS

Zoledronic acid therapy rapidly lowered bone pain together with a reduction of intramuscular myxoma volume, but did not affect the extension of fibrous dysplasia. No adverse effects have been observed during treatment.

CONCLUSION

Highly active bisphosphonates are commonly used for the treatment of bone metabolic disorders and they are generally well tolerated. Zoledronic acid may represent a promising alternative to surgical intervention in MS, although its use in rare form of bone fibrous dysplasias is still controversial.

Karyotyping and analysis of GNAS locus in intramuscular myxomas

Intramuscular myxoma is a benign soft tissue tumor about which very limited genetic information exists. We studied 68 intramuscular myxomas by means of chromosome banding analysis finding abnormal karyotypes in 21 of them. The most clearly nonrandom involvement was of chromosome 8 which was found gained in seven tumors (+8 was the sole change in five myxomas) and structurally rearranged in another two. Since mutation of the gene GNAS (20q13) has been implicated in the pathogenesis of both solitary and hereditary multiple myxomas, we assessed the transcription and mutation status of this gene in five tumors from which we had suitable RNA. All five intramuscular myxomas expressed biallelic transcripts. The mutated GNAS allele found in one tumor was also biallelically transcribed. In none of the five myxomas were maternally expressed transcripts detected. Collectively, the data suggest that intramuscular myxomas have acquired genetic abnormalities that often include chromosome 8 changes but may also involve alterations of GNAS. To what extent these aberrations are pathogenetically important, remains uncertain.

Intramuscular myxoma of the paraspinal muscles: A case report and systematic review of the literature

Intramuscular myxoma (IM) is a rare mesenchymal tumor of the head and neck region. The current study reports a case of a 45-year-old man who presented with a painless neck mass. Imaging showed involvement of the levator scapulae and scalene muscles. Core needle biopsy was consistent with intramuscular myxoma. Surgical excision was performed and follow-up for 30 months showed no recurrence. The present study includes a systematic review of head and neck IMs, with a summary of the clinical and demographic parameters of all reported cases in the head and neck region. Surgery was curative in 28 of the 29 published cases, as well as in the current case (96.7%), with the lone recurrent tumor cured following re-resection. Females constituted 57% of the cases and the mean age was 49.7±20.4 years. Although uncommon, IM should be considered in the differential diagnosis of deep neck masses, and surgical excision is the treatment of choice with a low risk of recurrence.

Chondrosarcoma of the femur in Mazabraud's syndrome: A first case study

Malignant transformation of fibrous dysplasia (FD) in long bones is rare (less than 1% of cases) and occurs in the form of osteosarcomas. They can occur on FD associated with multiple myxomas, which corresponds to Mazabraud syndrome. To our knowledge, only six cases of FD malignant transformation into osteosarcoma in the context of Mazabraud syndrome have been described. Here, we describe the first case of malignant transformation of femur FD into chondrosarcoma in a 51-year-old female patient. The patient had significant changes in the size and number of myxomas around the femur before the malignant transformation into chondrosarcoma. She underwent complete femur replacement with a favourable result after 4 years' follow-up. Close surveillance is strongly recommended in this syndrome, particularly when the number and size of myxomas increase.

Intramuscular myxoma of the cervical paraspinal musculature: case report and review of the literature

CASE

A 57year old female patient presented with a painful right-sided neck mass that on MRI was shown to be adherent to the posterior aspect of the sternocleidomastoid muscle. The mass was surgically resected en bloc without complications. Histopathologic analysis revealed the mass to be a myxoma.

REVIEW

To date, there have been several case reports of myxomas, although very few involving the head or neck. The majority of the literature available concurs that myxomas are benign neoplasms that exhibit characteristic qualities on MRI imaging. The definitive treatment by consensus is surgical excision.

CONCLUSIONS

Although the incidence of head and neck myxomas is low, it is important to include in the differential of a neck mass with certain radiographic findings.

Infiltrative intramuscular myxoma of the cervical spine: a case report

BACKGROUND CONTEXT

Myxomas are benign tumors of mesenchymal cell origin that usually present as solitary lesions. They are infrequently associated with fibrous dysplasia, as in McCune-Albright or Mazabraud syndrome. Myxomas can develop in a variety of locations, although the most frequent sites are the thigh, buttocks, shoulder, and upper arm. Intramuscular myxomas (IMs) refer to lesions that occur within muscle compartments. They have been infrequently reported in the neck musculature.

PURPOSE

To date, only five cases have been reported within the posterior neck muscles without associated intraspinal extension. To our knowledge, this is the first case of an IM presenting with extension into the spinal canal.

STUDY DESIGN

We report a case of posterior cervical IM with intraspinal extension presenting in a 63-year-old woman as a palpable mass.

METHODS

Complete intralesional resection of the tumor was achieved by standard midline posterior approach. Meticulous resection of the entire capsule was achieved and all margins were confirmed to be free of neoplasm.

RESULTS

A diagnosis of myxoma was provided on pathologic evaluation. Follow-up at 1.5 years confirmed maintained complete resolution of the preoperative symptoms, with no evidence of local recurrence on imaging.

CONCLUSIONS

Intramuscular myxomas should be included in the differential diagnosis of cervical paraspinal tumors. Furthermore, we suggest that masses involving the axial muscles should be closely monitored and the patient counseled regarding potential neurologic sequelae.

A case of intramuscular myxoma presenting as a swollen shoulder: a case report

INTRODUCTION

Intramuscular myxoma is a rare benign mesenchymal tumor. Myxomas most commonly occur in the heart. They may occur less frequently in aponeurotic tissues, bone, genitourinary tract, subcutaneous tissue and skin.

CASE PRESENTATION

The case described here is a 44-year-old Turkish woman who presented with the complaint of a swelling in her right shoulder. A preoperative magnetic resonance imaging revealed a lobular contoured mass lesion in her deltoid muscle. The mass was marginally excised and pathology revealed intramuscular myxoma.

CONCLUSION

Intramuscular myxoma of the deltoid muscle is a very rare benign tumor. In the differential diagnosis, reactive lesions, myxoid nodular fasciitis and low -grade myxoid sarcomas should be kept in mind, upon which the treatment should be planned.

Intramuscular myxoma of the buttock mimicking low-grade fibromyxoid sarcoma: diagnostic usefulness of MUC4 expression

Intramuscular myxoma (IM) is a benign intramuscular neoplasm composed of fibroblasts and abundant myxoid stroma. Some malignant soft tissue tumors can undergo myxomatous degeneration, which makes it difficult to distinguish them from IM. We describe a case of IM of the buttock region mimicking low-grade fibromyxoid sarcoma. The tumor appeared as a well-defined ovoid mass with a cystic lesion on MRI images, and mild uptake on PET images was seen. This was originally misdiagnosed as low-grade fibromyxoid sarcoma (LGFMS) after core-needle biopsy. The mass was excised en bloc and sent for histology. The surgical specimen showed the features of LGFMS with the same characteristics as those mentioned in the previous biopsy report. After surgery, MUC4 expression, a highly sensitive and specific immunohistochemical marker for LGFMS, and FUS gene rearrangement by FISH was not detected upon re-examination; therefore, a conclusive diagnosis of IM was made. The patient had no local recurrence at the 3-year follow-up. Our case suggests that IM with mild FDG uptake is frequently confused with other low-grade malignant myxoid tumors. In addition, absence of MUC4 expression is the definitive key to distinguish IM from LGFMS.

Intramuscular myxoma in the chest wall

Intramuscular myxomas are benign soft-tissue tumors that often develop in the thigh. A 66-year-old woman was referred with an abnormal shadow on chest roentgenogram. The tumor was well defined and smooth and originated from the second intercostal space. Positron emission tomography showed no accumulation of 18F-fluorodeoxyglucose in the tumor. The patient attended the outpatient department for follow-up care. Because the mass grew slightly after 52 months, the patient underwent complete removal by video-assisted thoracoscopic surgery. On histopathological examination, the tumor was diagnosed as an intramuscular myxoma in the chest wall. The patient has had no recurrence 3 years after surgery. A case of intramuscular myxoma in the chest wall, completely resected by video-assisted thoracoscopic surgery, is reported. A well-defined, smooth, homogeneous mass in the chest wall may therefore be intramuscular myxoma.

Adipose and myxoid tumors of childhood and adolescence

Adipose and myxoid tumors in children are an unusual and challenging group of neoplasms that have some unique aspects in contrast to these tumors in adults. Less than 10% of soft tissue neoplasms in the 1st 2 decades of life have an adipose phenotype and most are benign. The most common are various types of lipoma and lipoblastoma. Liposarcoma in young patients is rare and has a distinctive distribution of histologic subtypes, including classic myxoid liposarcoma, and unusual variants, such as pleomorphic-myxoid liposarcoma. Pathologic examination enhanced by adjunct techniques, such as immunohistochemistry and cytogenetic or molecular genetic studies, is useful for classification of difficult cases. Myxoid tumors can overlap with adipose tumors and are included in this review because of the morphologic similarities and importance of diagnostic accuracy. This article reviews the clinicopathologic features of adipose and myxoid tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents and the differential diagnosis.

Intramuscular myxoma of the left leg-Case report of the lesion observed for several years

AIM

The aim of this study was to present the process of diagnosis and treatment of a patient with diagnosed intramuscular myxoma in the left lower limb.

BACKGROUND

Myxomas are benign neoplasms which can be found within large muscle groups. Histologically, these neoplasms are composed of a few elongated or star-shaped cells lying in abundant mucoid stroma. These tumours are characterized by expanding growth without forming distant metastases.

CASE DESCRIPTION

A man, 58, came to the Surgical Oncology Outpatient Clinic due to pain ailments and a growing tumour located in the rear group of the left shank muscles. The patient had been observing the lesion for several years, but related the occurrence of pain to the change in the nature of his job - from sedentary to standing. The patient underwent diagnostic imaging, a magnetic resonance imaging test, in which a tumour was described. A surgery was carried out where the tumour was resected together with the lateral head of the gastrocnemius muscle. No significant walking disorders, neurological deficits, either sensory or motor were observed. The follow-up imaging examinations, which were carried out a year after the surgery, did not reveal a relapse. The patient remains under the care of the Surgical Oncology Outpatient Clinic.

CONCLUSION

Myxomas are a group of benign neoplasms whose first symptom is the appearance of a palpable tumour whose stretching growth causes painful ailments. After magnetic resonance imaging and a diagnosis, it is necessary to plan the surgery. Radical resection of the lesion is a method of choice which guarantees long-lasting recovery.

GNAS1 mutations occur more commonly than previously thought in intramuscular myxoma

Mutation detection plays an important role in diagnostic pathology, not only in providing a tissue diagnosis, but also in predicting response to antitumourigenic agents. However, mutation detection strategies are often hampered by masking of mutant alleles by wild-type sequences. Coamplification at lower denaturation temperature PCR (COLD-PCR) reportedly increases the proportion of rare variant sequences in a wild-type background by using PCR cycles in which the denaturation temperature is reduced to favour product formation with lower melt temperatures and heteroduplexes arising from minor variants. Intramuscular myxoma is a rare benign soft tissue neoplasm that occurs sporadically and less commonly in association with fibrous dysplasia (Mazabraud's syndrome). Fibrous dysplasia results from activating GNAS1 mutations, and the same mutations have been identified in small numbers of intramuscular myxoma. The aim of the study was primarily to establish whether COLD-PCR is more sensitive than conventional PCR; this was achieved by testing for GNAS1 mutations in intramuscular myxomas using the two methodologies. Mutations were detected in 8 of 28 (29%) cases of intramuscular myxomas using conventional PCR followed by mutation-specific restriction enzyme digestion (PCR-MSRED) whereas 17 of 28 (61%) mutations were detected using COLD-PCR/MSRED. Mutations were detected in two cases where a diagnosis of low-grade myxofibrosarcoma had been favoured over intramuscular myxoma. No mutations were detected in an additional 9 low-grade and 19 high-grade myxofibrosarcomas, and another 40 control samples. This study shows the power of COLD-PCR compared with conventional PCR in mutation detection, and shows that GNAS1 mutation detection increases diagnostic accuracy when distinguishing between intramuscular myxoma and low-grade myxofibrosarcoma.

Intramuscular myxoma of the cervical paraspinal muscle

Myxoma is a neoplasm of mesenchymal origin composed of undifferentiated stellate cells in a myxoid stroma. This tumor can develop in a variety of locations. Myxomas that arise from skeletal muscles are called intramuscular myxomas. They usually occur in large skeletal muscles. Only ten cases of these benign tumors involving the neck muscles were reported in literature. Of them, only three were located at the paraspinal muscles. A 64-year-old woman presented with occipital and neck pain over 5 years noted an expansive painful lesion located at posterior cervical region with progressive volume increase in the last 12 months. Image exams revealed a large mass located in the left posterior region of the neck in contact with the C2, C3 and C4 laminae with no invasion of the vertebrae. Tumor total removal was performed through normal muscle margins and the vertebral periosteum was scraped. The tumor was encapsulated, lobulated with a gray-white appearance. The histological examination yielded the diagnosis of intramuscular myxoma. Follow-up at 1 year showed complete resolution of preoperative symptoms and no evidence of local recurrence. In conclusion, although rare, intramuscular myxoma should be included in differential diagnosis of cervical paraspinal tumors. We reported the fourth case of intramuscular myxoma in the paraspinal musculature of the neck. Despite its benign characteristics, local recurrence was reported after subtotal resection. Tumor total removal should be the goal of surgery.

Peripheral odontogenic myxoma located on the maxillary gingiva: report of a case and review of the literature

BACKGROUND

Odontogenic myxoma is a rare, benign neoplasm and is often located in the maxillofacial region centrally most common in the mandible. Soft tissue localization that can be classified as a peripheral myxoma is rarely seen than the central localization. Peripheral myxoma is slowly growing and less aggressive compared to the central myxoma and has a low recurrence rate.

CASE REPORT

In this presentation, the patient with a peripheral odontogenic myxoma of the posterior maxillary gingiva was presented with histological findings following surgery, and the clinical differences and characteristics of the various types of myxomas were discussed by a review of the literature.

MRI appearances of common benign soft-tissue tumours

Benign soft-tissue tumours are many times more common than their malignant counterparts, and magnetic resonance imaging (MRI) is the technique of choice for imaging the lesions. This review illustrates the MRI appearances of the most common benign soft-tissue tumours, based on consecutive referrals to our institution. The imaging signs that are useful for diagnosis are described.

Co-existing fibrous dysplasia and atypical lymphoplasmacyte-rich meningioma

We report an unusual and extremely rare case of coexisting fibrous dysplasia of the sphenoid sinus with atypical lymphoplasmacyte rich meningioma (World Health Organization Grade II), right frontal lobe in a 25-year-old male. The patient presented with history of generalized tonic clonic seizures with a loss of vision in the right eye. Radiologically it was seen that the sphenoid sinus lesion was sclerotic and was extending and causing compression of the optic nerve. Magnetic resonance imaging revealed mass lesion in the right frontal lobe, iso to hypointense on T, weighted images and hyperintense on T2 weighted images with uniform contrast enhancement. Clinically and radiologically the possibility of fibrous dysplasia of the sphenoid bone and sinus with metastases in the frontal lobe from a different primary was considered. On histopathology the frontal lobe lesion showed a tumor composed of cells with vesicular nuclei, focal nuclear pleomorphism, a mitotic rate of = 4/10 high power field and a single focus of necrosis. The cells were arranged in fascicles and had a prominent lymphoplasmacytic infiltrate. In contrast, the sphenoid sinus lesion was composed of narrow, curved bony trabeculae with a characteristic fishhook configuration without osteoblastic rimming and interspersed with fibrous tissue of variable cellularity. Although no definite causative factors are described for the coexistence of these tumors, however, a common yet undetermined denominator in the origin has been proposed in the literature.

Not all pain in the left iliac fossa is diverticular disease: A case study of a psoas myxoma and review

Intramuscular myxomas are rare, benign, mesenchymal tumours that may present to a wide variety of specialties. We present a case study of an intramuscular myxoma in the psoas muscle, followed by a review of the literature regarding the diagnosis and treatment of intramuscular myxomas

Sonography of intramuscular myxomas: the bright rim and bright cap signs

OBJECTIVE

The objective of this study was to retrospectively review sonographic images of pathologically proven soft tissue myxomas to determine whether a sonographic correlate to the bright rim and bright cap signs described in the magnetic resonance imaging literature is present.

METHODS

The study group consisted of 6 patients with pathologically proven soft tissue myxomas (1 man and 5 women; age range, 41-72 years; mean, 56.5 years). The available sonographic images for each subject were retrospectively reviewed by 2 authors (L.F. and K.F.), with agreement reached by consensus. Among other findings, images were also reviewed for a peripheral rim of increased echogenicity (termed the "bright rim sign") and for the presence of a triangular hyperechoic area adjacent to at least one of the poles of the mass (termed the "bright cap sign").

RESULTS

The bright rim and bright cap signs were seen in 5 (83%) of the 6 myxomas. The single case without the bright cap sign was not the same case as the one lacking the bright rim sign.

CONCLUSIONS

The sonographic bright rim and bright cap signs were associated with 5 (83%) of the 6 intramuscular myxomas. These findings correlate with their magnetic resonance imaging equivalents, which are well documented in the literature, due to muscle atrophy and adjacent fatty infiltration. Recognition of these features may assist in a more accurate sonographic diagnosis before biopsy.

Intramuscular myxoma of scalene muscle: a case report

Intramuscular myxoma is a benign mesenchymal tumor that commonly occurs in the larger skeletal muscles, and is rare in the head and neck. A case of intramuscular myxoma in the scalene muscle is described. This is the first report of this tumor arising in that muscle. It is difficult to diagnose pre-operatively from clinical features, CT scan and ultrasonography of the neck because of the lack of characteristic manifestation or radiographic features. Intramuscular myxoma has an infiltrative tendency, so there are several reports of recurrence because of incomplete excision or enucleation. In our case no recurrence was observed for 4 years, since the tumor was removed with the muscle adherent to it.

Intramuscular Myxomas: A Clinicopathologic Study with Emphasis on Surgical Management

Intramuscular myxomas (IMs) are rare myxoid tumors named for their abundance of noncollagenous mucinous stroma. IMs are benign tumors characterized by a paucity of cells, diminished vascularity, and minimal mitotic figures. The objectives of this study were to examine clinicopathologic features of IM and to discuss clinical management of these unusual soft tissue tumors. A 10-year retrospective study at Orlando Regional Medical Center was conducted from May 1993 to May 2003. A case report of a 48-year-old male with a right gluteal mass is presented. Four cases with histologically confirmed diagnosis of intramuscular myxoma were reported. Three patients presented with lesions of the lower extremity and one with an extrafascial IM of the eighth rib. One of the lower extremity cases was shown to be cellular myxoma, a recently characterized subtype of IM. All cases were treated with at least marginal excision of the mass. There have been no known recurrences. Our findings are consistent with described characteristics for IM with respect to anatomic location and gross and microscopic appearance. As it may be unreliable to differentiate IM from malignant myxoid tumors preoperatively, we favor excision with wide margins in the surgical management of these tumors.

Mazabraud’s syndrome: Intramuscular myxoma associated with fibrous dysplasia

The association of fibrous dysplasia and intramuscular myxoma is a rare disease known as Mazabraud's syndrome. Both lesions tend to occur in the same anatomical region. The relationship between fibrous dysplasia and myxoma remains unclear, where an underlying localized error in tissue metabolism has been proposed to explain this occasional coexistence. Another example of this syndrome in a 52 year-old woman is reported. The patient presented with a soft tissue mass at the anteromedial mid part of the left thigh. After excision of the mass, three separate bone lesions were detected in her control MRI. The soft tissue mass was misdiagnosed as liposarcoma in another center, and the bone lesions were interpreted as metastasis. The hypocellularity and the indistinct vascular pattern of the lesion were consistent with myxoma. The Jam-Shidi needle biopsies of the osseous lesions were diagnosed as fibrous dysplasia. The recognition of this entity is important for appropriate management of the patient. Patients with soft tissue myxomas should be thoroughly examined for fibrous dysplasia. The greater risk of sarcomatous transformation in fibrous dysplasia with Mazabraud's syndrome should also be kept in mind.