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

Intramuscular Eyelid Myxoma

Myxomas are a heterogeneous group of mesenchymal tumors. Soft tissue myxomas are divided into myocardial, intramuscular, juxta-articular, superficial, aggressive, and nerve sheath myxomas. Although benign, myxomas have site-specific biologic behavior and syndromic associations, which can influence prognosis and management. In addition, myxomas need to be distinguished from malignant neoplasms, such as myxofibrosarcomas, low-grade fibromyxoid sarcomas, myxoid liposarcomas, and peripheral nerve sheath tumors. While myxomas can occur throughout the body, these tumors arise more commonly in the thigh, shoulder, buttocks, and upper extremity, and less often in the head and neck. Rarely, myxomas can arise in a periocular location, typically in the conjunctiva and eyelid skin. In this case report, we present a patient with recurrent intramuscular myxoma of the eyelid and discuss the differential diagnosis and syndromic associations of this neoplasm. To our knowledge, there have been no prior reports of intramuscular myxoma of the eyelid and orbit.

Intramuscular Myxoma of the Intrinsic Muscles of the Tongue: A Case Report with Literature Review

Myxoma is a benign tumor of mesenchymal origin. It frequently occurs in the muscles of the hip and extremities; however, it rarely occurs in the head and neck region. This report describes the second case of an intramuscular myxoma of the tongue. A 23-year-old woman was referred to our institution for the diagnosis and treatment of a left tongue lesion. T2-weighted magnetic resonance imaging revealed an 8 × 6-mm mass in the tongue. Based on a clinical diagnosis of a tongue tumor, excisional biopsy was performed under general anesthesia. The histopathological diagnosis was an intramuscular myxoma. The postoperative course was uneventful, and there was no evidence of tumor recurrence 3 years after surgery.

Spinal myxomas: review of a rare entity

Intramuscular myxomas are rare, benign mesenchymal tumours, occurring predominantly in large skeletal muscles as large, slow-growing and painless masses. Spinal occurrence is rare, and may present incidentally, or diagnosed via localized symptoms secondary to local infiltration of surrounding structures. Differential diagnosis based on imaging includes sarcomas, meningiomas and lipomas. We discuss two contrasting cases presenting with well-circumscribed cystic paraspinal lesions indicative of an infiltrative tumour and discuss the radiological and histological differences that distinguish myxomas from similar tumours. Surgical resection of the tumour was performed in both cases, however one patient required surgical fixation due to bony erosion secondary to tumour infiltration. Immuno-histopathological analysis confirmed the diagnosis of a cellular myxoma. Follow up imaging at 6 months confirmed no symptomatic or tumour recurrence in both cases. Histological analysis is the definitive means for diagnosis to differentiate myxomas from other tumours. Recurrence is rare if full resection is achieved.

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.

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.

Intramuscular Myxoma in the Supinator Muscle with Transient Postoperative Posterior Interosseous Nerve Palsy: A Case Report

Background:

Intramuscular myxomas are rare, benign mesenchymal tumors in the musculoskeletal system, and usually, the tumors arise in the large muscles of the thigh, buttocks, shoulder, and upper arm. However, a tumor of the forearm is very rare. Herein, we describe the case of an intramuscular myxoma in the supinator muscle of a 56-year-old female patient.

Case Presentation:

Magnetic resonance imaging showed a well-defined mass that was hypointense with the peritumoral fat ring sign. The differential diagnoses might have been myxoma, schwannoma, or intramuscular hemangioma. The histopathological image showed abundant myxoid tissue, hypocellularity, and poor vascularization. The cells of the tumor were spindle and stellate-shaped with normochromic nuclei. Based on these findings, the pathological diagnosis was an intramuscular myxoma. After excising the tumor, the patient had transient posterior interosseous nerve palsy.

Conclusion:

This tumor is curative by resection in toto; however, when the tumor exists in the forearm, surgeons should be careful to avoid damaging surrounding tissues because the tumor is very hard and relatively large compared to the forearm.

Post-biopsy MRI changes in the size and enhancement of intramuscular myxomas: A report of two cases

Intramuscular myxomas are benign soft-tissue tumors, characterized by bland spindle-shaped cells and fibroblasts within an abundant mucoid matrix on histologic examination. Classically, these are slowly enlarging masses which may occasionally cause pain, paresthesia, and muscle weakness secondary to mass effect. We present an interesting phenomenon of two histologically confirmed cases of intramuscular myxomas that exhibited size and enhancement changes on follow-up imaging after image-guided biopsy. To our knowledge, this is the first report to describe size and enhancement changes of intramuscular myxomas after biopsy.

An Interesting Case of Intramuscular Myxoma with Scapular Bone Lysis

Introduction. Intramuscular myxoma is a rare benign primitive tumor of the mesenchyme founded at the skeletal muscle level; it presents itself like an unpainful, slow-growing mass. Myxomas with bone lysis are even more rare; only 7 cases have been reported in the English literature, but never at the shoulder level. Case Presentation. We describe an 83-year-old patient with a growing mass in the deltoid muscle with unique scapular lysis, without any symptom. Magnetic resonance imaging (MRI) and a biopsy were performed and the diagnosis of intramuscular myxoma has been retained. In front of this diagnosis of nonmalignant lesion, the decision of a simple follow-up was taken. One year after this decision, the patient was still asymptomatic. Conclusion. In the presence of an intramuscular growing mass with associated bone lysis, intramuscular myxoma as well as malignant tumor should be evoked. MRI has to be part of the initial radiologic appraisal but biopsy is essential to confirm the diagnosis. By consensus, the standard treatment is surgical excision but conservative treatment with simple follow-up can be an option.