A calcification mass was incidentally found in the soft tissue of a patient who had a history of trauma to the extremity during examination. The patient had no symptom. The pathological analysis of the mass revealed it was an early-phase synovial sarcoma (SS). The diagnosis was made before the onset of symptoms and proper surgical intervention was performed. Therefore, in case of a <1 cm lesion clinically suspicious of myositis ossificans, SS should be taken into consideration as a possible diagnosis.
Diagnosis ; Extremities ; Femur ; Humans ; Myositis Ossificans ; Myositis ; Sarcoma, Synovial

Myositis ossificans (MO) is a benign condition of non-neoplastic heterotopic bone formation in the muscle or soft tissue. Trauma plays a role in the development of MO, thus, non-traumatic MO is very rare. Although MO may occur anywhere in the body, it is rarely seen in the lumbosacral paravertebral muscle (PVM). Herein, we report a case of non-traumatic MO in the lumbosacral PVM. A 42-year-old man with no history of trauma was referred to our hospital for pain in the low back, left buttock, and left thigh. On physical examination, a slightly tender, hard, and fixed mass was palpated in the left lumbosacral PVM. Computed tomography showed a calcified mass within the left lumbosacral PVM. Magnetic resonance imaging (MRI) showed heterogeneous high signal intensity in T1- and T2-weighted image, and no enhancement of the mass was found in the postcontrast T1-weighted MRI. The lack of typical imaging features required an open biopsy, and MO was confirmed. MO should be considered in the differential diagnosis when the imaging findings show a mass involving PVM. When it is difficult to distinguish MO from soft tissue or bone malignancy by radiology, it is necessary to perform a biopsy to confirm the diagnosis.
Biopsy ; Buttocks ; Diagnosis, Differential ; Magnetic Resonance Imaging ; Muscles ; Myositis ; Myositis Ossificans ; Osteogenesis ; Physical Examination ; Thigh

Adolescent ; Diagnosis, Differential ; Female ; Humans ; Myositis Ossificans ; diagnosis

We describe two unusual cases of benign acute childhood myositis (BACM). A 24-month-old toddler presented with gait disturbance without the elevation of creatine kinase in the hyperacute stage of the disease, which initially led to an erroneous diagnosis. However, the following sample showed an elevation of creatine kinase, and the diagnosis of BACM was made. The other case was a 9-year-old girl who had three successive recurring gait disturbances with a delayed recovery from the third occurrence. Each episode occurred within a short period and was consistent with symptoms of BACM. These two cases may broaden the clinical spectrum of BACM.
Child ; Child, Preschool ; Creatine Kinase ; Diagnosis ; Female ; Gait ; Humans ; Myositis*

PURPOSE: To perform and compare differential diagnosis of patients with thyroid-associated myopathy, idiopathic orbital myositis and normal controls based on orbital computed tomography. Orbital fat and extraocular muscle densities were quantified using Hounsfield Unit (HU) and their characteristics were compared and analyzed. METHODS: From February 2005 to January 2013, orbital computed tomography was performed on 90 eyes of 47 thyroid-associated myopathy patients, 18 eyes of 14 idiopathic orbital myositis patients and 280 eyes of 140 normal subjects. The average values of orbital fat and extraocular muscle densities were measured and compared using HU. The density differences between the patients with thyroid-associated myopathy and the normal group were analyzed by age, clinical activity score, ocular protrusion and disease duration. RESULTS: In the thyroid-associated myopathy group, orbital fat and extraocular muscle densities were -87.8 +/- 12.5 HU and 48.7 +/- 7.1 HU, respectively. In the idiopathic orbital myositis group, the orbital fat and extraocular muscle densities were 79.9 +/- 9.9 HU and 49.2 +/- 9.1 HU, respectively. There was a statistically significant lower result of orbital fat in the thyroid-associated myopathy group (p = 0.002), however, the extraocular muscle density did not show a statistically significant difference (p = 0.775). The orbital fat and extraocular muscle densities of the normal group were -79.0 +/- 11.2 HU and 54.3 +/- 6.3 HU, respectively. There were significantly lower results in both orbital fat and extraocular muscle densities in the thyroid-associated myopathy group than normal group (p = 0.000). In active cases and those accompanied by ocular protrusion, there was no significant difference in orbital fat density (p = 0.345 and p = 0.952, respectively), while extraocular muscle density significantly decreased (p = 0.007 and p = 0.003, respectively). CONCLUSIONS: A difference between the orbital fat and extraocular muscle densities in thyroid-associated myopathy and idiopathic orbital myositis could be quantitatively found using HU and orbital computed tomography.
Diagnosis, Differential ; Humans ; Muscles* ; Muscular Diseases* ; Orbit* ; Orbital Myositis*

To evaluate MR findings of soft tissue masses in extremities and to find the helpful findings of distinguish benignity from malignancy, 28 soft tissue masses (22 benign and 6 malignant) in extremities were reviewed. T1-weighted, proton density, T2-weighted and Gd-DTPA enhanced images were obtained. MR images allowed a specific diagnosis in a large number of benign masses, such as hemangioma(8/9), lipoma(2/2), angiolipoma(1/1), epidermoid cyst(2/2), myositis ossificans(1/1), synovial chondromatosis(1/1) and pigmented villonodular synovitis (1/2). Specific diagnosis was difficult in the rest of the masses including malignancy. However, inhomogenous signal intensities with necrosis and inhomogenous enhancement may suggest malignant masses.
Diagnosis ; Extremities ; Gadolinium DTPA ; Myositis ; Necrosis ; Protons ; Synovitis, Pigmented Villonodular

Child ; Humans ; Male ; Myositis ; diagnosis ; drug therapy ; pathology

PURPOSE: To present a rare case of idiopathic orbital myositis involving levator palpebrae superioris. CASE SUMMARY: A 27-year-old male presented with a 1-week history of redness, discomfort, swelling, and drooping of his left upper eyelid. A computed tomography scan showed isolated enlargement of the right superior rectus/levator muscle complex. On examination, there was a left blepharoptosis, although eye movements were normal. The authors treated the patient with 3rd-generation cephalosporin; however, after 3 days, the symptoms did not improve. Subsequently, the patient was diagnosed with idiopathic orbital myositis and treated with oral corticosteroids for 1 month; the symptoms gradually resolved. CONCLUSIONS: Idiopathic orbital myositis is a subtype of nonspecific orbital inflammation primarily involving the extraocular muscles. Although the exact cause of orbital myositis is unknown, an immune-mediated pathophysiologic mechanism appears to be one of the causes. Medial rectus myositis is the most common, and isolated levator muscle myositis is very rare. The authors of the present study reported a case of orbital myositis involving the levator palpebrae superioris which should be considered a differential diagnosis of blepharoptosis with eyelid swelling.
Adrenal Cortex Hormones ; Adult ; Blepharoptosis ; Diagnosis, Differential ; Eye Movements ; Eyelids ; Humans ; Inflammation ; Male ; Muscles ; Myositis ; Orbit ; Orbital Myositis

Inclusion body myositis (IBM) is a chronic inflammatory myopathy with characteristic rimmed vacuoles. Cytoplasmic and intranuclear filamentous inclusions in muscle speci men. The clinical features manifest male dominance with the onset between the second and eighth decade but usually after the age of 50 years. Slow progression of painless muscle weakness, normal or mildly elevated serum CK level, myopathic and neurogenic eIectromyographic patterns and refractory to steriod therapy. The presence of rimmed vacuoles and filamentous inclusions in myofiber gives an important clue in the diagnosis of IBM, however, it is very difficult to differentiated young age onset IBM with distally predominant muscle weakness from distal myopathy with rimmed vacuole formation. While we present a young female patient who had slow progression of painless distal muscle weakness in both upper and lower extremities for 1 year, previously published articles concerning of IBM and distal myopathy with rimmed vacuole formation are reviewed and our own differential points are discussed in the diagnosis of this case as IBM.
Cytoplasm ; Diagnosis ; Distal Myopathies ; Female ; Humans ; Inclusion Bodies* ; Lower Extremity ; Male ; Muscle Weakness ; Muscular Diseases* ; Myositis ; Myositis, Inclusion Body* ; Vacuoles

The purpose of this study is to evaluate the clinical features and efficacy of therapeutic method of 14 pseudotumor patients with radiologically suspected orbital myositis. Retrospective analysis was performed to elucidate correlation with clinical finding, ocular symptom and sign, involved muscles, therapeutic response, and combined ocular diseases. Patients enrolled in this study were 5 men(35.7%) and 9 women(64.3%) (mean age 38.9 years). Two(14.3%) of 14 patients had bilateral disease, 9(64.3%) in the left eye, and 3(21.4%) in the right. The characteristic signs and symptoms included proptosis(35.7%), eyelid swelling(28.6%), periocular pain(28.6%), diplopia(14.3%), and blepharoptosis(7.1%). Radiologically, the medial and superior rectus muscles were affected in equal frequency(64.3%) as were the lateral and inferior rectus muscles(42.9%). Therefore, 11(71.4%) of 14 patients had enlargement of at least 2 muscles. Drug therapy such as ibuprofen, indomethacin, and prednisolone or radiation therapy of pseudotumor with the orbital myositis was less effective in case of patients with the longer duration of myositis than 1 year or involved all the rectus muscles. These patients usually accompany optic neuropathy(35.8%), paranasal sinusitis(28.6%), ocular hypertension(28.6%), scleritis(14.3%), keratitis(14.3%), dry eye(14.3%), and dacryoadenitis(7.1%). In view of the results of this study, when a case presents clinically suspected pesudotumor with the inflammatory reaction or enlargement of extraocular muscle on CT or MRI, it is suggested that the early differential diagnosis, such as orbitoathy of Graves` disease, neoplastic disorder, ateriovenous malformation be made, and that proper treatment of the orbital myositis be institued for good prognosis of disease.
Diagnosis, Differential ; Drug Therapy ; Eyelids ; Humans ; Ibuprofen ; Indomethacin ; Magnetic Resonance Imaging ; Muscles ; Myositis ; Orbit* ; Orbital Myositis* ; Prednisolone ; Prognosis ; Retrospective Studies