Focal myositis: an unusual cause of bilateral upper eyelid swellings

Focal Eosinophilic Myositis Affecting the Orbicularis Muscle: Clinical and Image Aspects

Focal eosinophilic myositis (FEM) is a rare disease that is even more uncommon in affecting the periocular area. The authors are reporting the first case of FEM occurring in the lower eyelid of a 45-year-old Caucasian female who presented with localized painful area of glossy induration and peau d'orange skin lesion. Magnetic resonance image shows significant hyperintense thickening of the pre-septal orbicularis muscle region on T2-weighted images. Incisional biopsy of the induration revealed marked fibrinoid degeneration of the orbicularis muscle and adjacent fascia, mixed cellular infiltration of lymphocytes and eosinophils and a predominant CD8+ lymphocytic infiltrates in the immunohistochemical study. The final diagnosis was FEM. Oral prednisolone improved symptoms and the lesions disappeared, with no recrudescence in a one year follow-up.

Focal myositis: a rare case report

Focal myositis is an uncommon, self-limiting, benign skeletal muscle disease, which is generally determined as an inflammatory pseudotumor. The etiology is not fully known, although it has been suggested that subclinical damage may play a role. As it leads to a tumoral mass it may be confused with several diseases leading to incorrect evaluations. Definitive diagnosis is made by biopsy of the skeletal muscle. In radiologic diagnosis, magnetic resonance imaging is the most important modality. In this paper we presented the imaging findings of a 58-year-old female patient with focal myositis who was admitted with complaints of forearm swelling.

Recurrent Bilateral Focal Myositis

This report describes a rare case of recurrent bilateral focal myositis and its successful treatment via methotrexate. A 38-year-old man presented myalgia of the right gastrocnemius in May 2005. Magnetic resonance imaging showed very high signal intensity in the right gastrocnemius on short-tau inversion recovery images. A muscle biopsy revealed inflammatory CD4+ cell-dominant myogenic change. Focal myositis was diagnosed. The first steroid treatment was effective. Tapering of prednisolone, however, repeatedly induced myositis relapse, which progressed to multiple muscle lesions of both lower limbs. Initiation of methotrexate finally allowed successful tapering of prednisolone, with no relapse in the past 4 years.

Self-resolving focal non-ossifying myositis: a poorly known clinical and imaging entity diagnosed with MRI

Background

Focal myositis is a rare benign inflammatory pseudotumor, presenting as a painful nodular mass within a muscle, and characterized by spontaneous resolution within weeks.

Purpose

To assess the clinical and imaging findings of focal nodular myositis simulating a neoplasm at clinical examination, with no history of trauma.

Material and Methods

This study describes the locations and appearance at ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) of this condition in a series of five patients.

Results

MRI and US displayed a solid intramuscular “tumor” and suggested a continuum between the proximal and distal muscle fibers that appeared thickened within the nodular lesion, a sign that has been reported in myositis ossificans. MRI showed edema in adjacent muscles and soft tissues, as well as intense enhancement of the mass. Intense vascular flows were seen at Doppler analysis. CT did not reveal the appearance of peripheral ossifications, ruling out the diagnosis of myositis ossificans. In some patients, the diagnosis of sarcoma had been suggested as possible by the radiologist. Imaging follow-up with MRI showed complete resolution of the masses over several weeks, thus avoiding a biopsy; no recurrence was observed at long-term follow-up (more than 24 months).

Conclusion

This paper highlights MRI and US findings in focal non-ossifying myositis, and emphasizes the role of MRI in suggesting this diagnosis, leading to the careful follow-up of the lesion until its resolution, and ruling out more aggressive lesions.

Focal Myositis in paediatric age

BACKGROUND

Focal Myositis is a rare pseudotumor of unknown aetiology that is often difficult to diagnose and treat. Typically afflicting people in adulthood, it has occasionally been reported also among children.

PURPOSE

the aim of this study is to review the literature of Focal Myositis in paediatric age in order to compare the clinical manifestation and the various treatment suggested by different authors.

METHODS

this article describes a 6-year-old boy with focal myositis in gracilis muscle successfully treated by conservative methods, including nocturnal leg traction, intensive physiokinesi therapy and articulated knee orthosis guided to progressive extension. Furthermore a systematic review of literature concerning focal myositis in paediatric age is reported.

CONCLUSION

our case and the review of literature suggests that conservative methods should be the first-choice treatment for FM in paediatric age and that surgery should be strictly reserved for selected cases where non-invasive methods have previously failed.

Fibroblastic and myofibroblastic tumors in children and adolescents

Fibroblastic and myofibroblastic tumors in children and adolescents are a relatively common group of soft tissue proliferations that range from reactive to hamartomatous to neoplastic, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic and immunohistochemical overlap, despite significant clinical, genetic, and prognostic differences. The fibromatoses are a major subgroup, and all types of fibromatoses can occur in the 1st 2 decades of life. Intermediate and malignant fibroblastic-myofibroblastic tumors are an important group that includes variants of fibrosarcoma and other tumors with recurrent cytogenetic or molecular genetic abnormalities and low metastatic potential. Pathologic examination is enhanced by adjunct techniques, such as immunohistochemistry, cytogenetics, and molecular genetics, although morphology provides the ultimate criteria for a specific diagnosis. This article reviews the clinicopathologic features of fibroblastic and myofibroblastic tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents, the use of diagnostic adjuncts, and differential diagnoses.

Focal myositis: a clinicopathologic study of 115 cases of an intramuscular mass-like reactive process

BACKGROUND

Focal myositis is an uncommon inflammatory pseudotumor of skeletal muscle that can be confused with a variety of neoplastic and inflammatory diseases. It is often misunderstood because it presents as a tumor-like mass, but histologically resembles a skeletal muscle myopathy or dystrophy. We wanted to discuss the detailed morphologic and immunophenotypic features of the largest reported group of focal myositis patients.

DESIGN

Two hundred and six cases coded as "focal myositis" were culled from our files. Only 115 cases with adequate material, a solitary lesion, and correct diagnosis were included. A variety of immunohistochemical studies were performed, as were polymerase chain reaction for T cell receptor gene rearrangement and immunoglobulin heavy chain rearrangement.

RESULTS

Age ranged from 7 to 94 years (mean 41, median 36 y). Most patients were otherwise healthy, and with the exception of 10 cases, lacked antecedent trauma. Masses that ranged in size from 1.0 to 20.0 cm (median 3.0 cm, mean 3.9 cm) were reported in specific muscles of the lower extremities (including vastus lateralis, adductor muscle, and groin muscles, n=39; gastrocnemius, n=22), followed by the trunk, neck (mentalis, n=8; sternocleidomastoid muscle, n=8), and upper extremity. Histologically, these were solitary intramuscular processes composed of variable myopathic (93%) and focal neurogenic (89%) changes, fibrosis, and inflammation (97%), occasionally accompanied by prominent eosinophils (n=20). By immunohistochemistry, most cases had CD163-positive macrophages that were negative for S100 protein and CD1a. Lymphocytes were mostly CD3, CD4-positive lymphocytes that were negative for cytotoxic markers, TIA-1 and granzyme-B. Polymerase chain reaction did not show B cell or T cell rearrangement. In situ studies for Epstein-Barr-encoded receptor were negative, as was ALK-1 immunohistochemistry. Major histocompatibility complex-1 and weak IgG4 were focally positive in skeletal muscle. Cases with severe inflammation had increased numbers of CD20-positive B cells and CD123-positive plasmacytic dendritic cells. S100 was strongest in skeletal muscle fibers with vacuolar change. Clinical diagnostic considerations ranged from benign entities such as rhabdomyoma, intramuscular lipoma, fibromatosis, myositis ossificans, proliferative myositis, inflammatory myofibroblastic tumor, and inflammatory myopathy to malignant entities such as rhabdomyosarcoma, leiomyosarcoma, liposarcoma, and lymphoma. Available follow-up revealed spontaneous regression.

CONCLUSIONS

Focal myositis occurs in specific muscle groups of young adults of both sexes without significant trauma. It is a largely unrecognized entity with specific histology including myopathic, focal neurogenic, fibrosis, and inflammatory features. It can be easily mistaken for an inflammatory myopathy, dystrophy, alternate reactive, or even neoplastic process. Focal myositis seems to be a macrophage and T-cell-rich lesion that changes to B cell and dendritic plasmacytoid cells when markedly inflamed, but does not seem to have a known viral or molecular etiology. IgG4 presence may be linked to the fibrosis in these lesions; a possible transient autoimmune etiology cannot be excluded. Careful attention to reproducible clinicopathologic features can aid diagnosis and spare patients from excessive surgery or adverse therapy.

MR imaging findings of focal myositis: a pseudotumour that may mimic muscle neoplasm

OBJECTIVE

The authors describe magnetic resonance (MR) findings in eight patients with histologically confirmed focal myositis.

MATERIALS AND METHODS

In each patient, axial TSE T1-weighted and fast short-tau inversion recovery (STIR) images were obtained using a 1.5-T MR scanner. Three patients also underwent dynamic contrast-enhanced MR examination using a GE T1-weighted sequence. The following features were evaluated: anatomical distribution, extent of the involvement, signal intensity characteristics, dynamic enhancement pattern and outcome at follow-up examinations.

RESULTS

Seven of eight lesions were located in the lower extremities, one of eight in the arm; four of eight involved part of a muscle, two of eight diffusely involved a muscle and two of eight showed multifocal involvement of two or more muscles. All lesions were hyperintense on fast-STIR images: the hyperintensity was homogeneous in six of eight and inhomogeneous in two of eight. On T1-weighted unenhanced images, all lesions but two appeared isointense or slightly hypointense in comparison to normal muscles; two lesions showed a slight hyperintensity. Dynamic enhancement pattern corresponded to the type usually seen in benign soft tissue lesions. All lesions disappeared.

CONCLUSION

Focal myositis is an uncommon pseudotumour which should be considered in the differential diagnosis of muscular masses and myopathies.

Masticator myopathy

A 31-year-old woman developed low-grade fever and pain and swelling of the masticatory muscles. A T2-weighted magnetic resonance image showed high signal intensity in these muscles. Coxsackie B3 and echo 30 viruses were detected from a nasopharyngeal swab and feces, respectively. The clinical symptoms accompanied a marked decline in the serum immunoglobulin G level with progressive eosinophilia. Her symptoms disappeared by 8 weeks after onset. She was diagnosed as having masticator myopathy, which has rarely been reported in humans. The present case suggests that masticator myopathy is associated with coxsackie or echo virus infection.

Overview of the radiology of connective tissue disorders in children

This review article describes the imaging finding of the connective tissue disorders in children. The radiological features of the following conditions are described; the spondyloarthropathics, systemic lupus erythematosus (SLE), dermatomyositis, scleroderma, the vasculitides, Kawasaki disease, synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO), and focal myositis. The features on several integrated imaging techniques are described.

Focal myositis presenting with radial nerve palsy

Focal myositis is a rare inflammatory pseudotumor of skeletal muscle which usually has a benign course. We report a 56-year-old woman with a painful mass in the left arm with a radial nerve palsy. Magnetic resonance imaging (MRI) of the left arm showed a mass in the triceps muscle that was suggestive of a soft-tissue sarcoma. Electromyography showed a severe radial neuropathy involving both motor and sensory axons. An open biopsy showed focal myositis. Treatment with corticosteroids resulted in complete disappearance of the mass clinically and by MRI, without recurrence for more than 2 years. Radial nerve function also recovered completely. As a treatable cause of focal neuropathy, focal myositis should be included in the differential diagnosis of a muscle mass.

Focal myositis presenting as pseudothrombophlebitis of the neck in a patient with mixed connective tissue disease

This report describes a case of focal myositis in a patient with mixed connective tissue disease. The patient presented with diffuse neck swelling and pseudothrombophlebitis of the left internal jugular vein. Other clinical features included a high fever, elevated erythrocyte sedimentation rate, and prompt improvement after administration of high-dose intravenous corticosteroid therapy. Criteria for polymyositis were absent, serum levels of creatine kinase remained normal, and there was no sign of recurrence during 3 years of followup. Results of immunoprecipitation for anti-Jo-1 and other myositis-specific autoantibodies remained negative in serial serum samples obtained before, during, and after the episode.

Focal myositis of the floor of mouth: report of two cases and review of the literature

Focal myositis is an uncommon inflammatory myopathy of unknown cause affecting skeletal muscle. It may be mistaken on clinical evaluation for a malignant neoplasm. We describe two cases, both involving the mylohyoid muscle of the floor of the mouth. In each case excisional biopsy of a firm indurated mass revealed a focal lymphocytic and histiocytic infiltrate associated with degenerating and regenerating skeletal muscle fibers. No clinical or biochemical evidence of generalized muscle disease was seen at presentation or at 1-year and 7-year follow-up examination. The literature on focal myositis involving the head and neck region is reviewed.

Pseudosarcomatous proliferative lesions of soft tissues

The pseudosarcomatous proliferative lesions of soft tissues are fascia-based fibroblastic and myofibroblastic lesions that have the potential to be overdiagnosed as sarcomas. They may be subtyped according to depth of involvement, age at presentation, and certain histologic features. Subtypes are proliferative fasciitis, proliferative myositis, nodular fasciitis, intravascular fasciitis, and cranial fasciitis. They are presumed to be reactive. Recurrences are rare after tissue-sparing surgical excision.