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

Drop Head Syndrome as a Rare Complication in Mixed Connective Tissue Disease

A 54-year-old woman developed drop head syndrome (DHS), Raynaud's phenomenon and creatine kinase (CK) elevation. She did not meet the international classification criteria of dermatomyositis/polymyositis, as we observed no muscle weakness, grasping pain or electromyography abnormality in her limbs, and anti-aminoacyl tRNA synthetase (ARS) antibody was negative. Cervical magnetic resonance imaging and a muscle biopsy of the trapezius muscle revealed myositis findings as the only clinical observations in muscle. These findings, along with her anti-U1-ribonucleoprotein (RNP) antibody positivity and leukopenia, resulted in a diagnosis of mixed connective tissue disease (MCTD). Prednisolone treatment significantly improved her myositis. To our knowledge, this is the first report of DHS as the only muscle complication of MCTD.

Focal myositis presenting as pseudothrombophlebitis of the arm

We described a 21-year-old woman with a diagnosis of Sjögren syndrome that came for consultation with a localized mass over her left arm of fast growth. Lab results were normal; a Doppler ultrasound showed the presence of partial thrombosis in the left axillary vein; a magnetic resonance imaging showed edema on the biceps muscle and the biopsy of the mass disclosed the presence of severe lymphocyte infiltrate within the connective tissue and scarce muscle fibers. Immunostaining showed positive results for antígeno comun leucocitario in spanish (leukocyte common antigen) (ACL) and CD3. Those results are consistent with the diagnosis of focal myositis. The patient was treated with low doses of prednisone and methotrexate, with good response.

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.

Disseminated Histoplasma capsulatum infection presenting with panniculitis and focal myositis in rheumatoid arthritis treated with etanercept

We report the case of a patient with rheumatoid arthritis (RA) on etanercept who presented with panniculitis and focal myositis as manifestations of disseminated histoplasmosis. Systematic search of the literature showed 11 additional case reports of disseminated histoplasmosis with tumour necrosis factor-alpha (TNFalpha) blockade therapy (infliximab, n = 8; etanercept, n = 3). Although disseminated histoplasmosis may manifest with classical symptoms of fever and respiratory complaints, it may also present atypically, such as with panniculitis and focal myositis. This review illustrates and emphasizes the importance of being highly suspicious for infection, including by opportunistic organisms, and to exclude such process in patients treated with a TNFalpha inhibitor when faced with unusual complications, even when an alternative aetiology appears plausible.

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.

Inflammatory focal myositis of the sternomastoid muscle: is there an absolute indication for biopsy? A case report and review of the literature

Focal myositis is a localised inflammatory process affecting skeletal muscles belonging to the pathological group of inflammatory pseudo tumours of soft tissue that includes myositis ossificans, proliferative myositis and nodular pseudosarcomatous fasciitis. Very rarely, it may affect one of the neck muscles and present as a neck lump, in which case both the clinical and pathological picture can mimic a sarcoma. We describe a case of focal myositis of the sternocleidomastoid muscle, present a review of this rare condition and debate the necessity of biopsy.

Muscle Involvement in Mixed Connective Tissue Disease

Muscle disease has been recognized as a common feature of mixed connective tissue disease (MCTD) since its first description in 1972. In the absence of clinical trials that are directed specifically at the myositis of MCTD, patients should be treated in the manner that is recommended for other forms of myositis. Myositis of MCTD may have a better prognosis than other forms of myositis.

[Biceps crural myositis after an insect bite]

INTRODUCTION

It can be difficult to diagnose focal muscular disease. We report a case of crural biceps focal myositis after an insect bite.

DISCUSSION

We then discuss diagnostics of one or a small number of muscle injury. Focal inflammatory myositis has been described. We emphasize the role of pathology. In our case, pathological examination rules out inflammatory or tumoral disease and access likely toxical etiology. Muscle injury can appear, most frequently around the bite of venomous animal.

CONCLUSION

Hymenopters are often responsible for such stings in France. Venoms are toxic for muscle cells membrane.

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, steroid responsive myositis causing dropped head syndrome

The dropped head syndrome, which occurs in a variety of neuromuscular disorders, is usually not due to an inflammatory process and generally either self-limited or nonresponsive to therapy. We present an 80-year-old woman who developed progressive neck weakness over a few months due to a focal and restricted inflammatory process involving the neck extensor muscles. She responded dramatically to treatment with immunosuppressive therapy.