Proliferative myositis in a child

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 1: tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous-organ soft tissues, as well as the peripheral and autonomic nervous system.

Proliferative myositis in the right brachioradialis: A case report

Proliferative myositis is a rare, self-limiting, benign disease. Its diagnosis can be difficult and in many cases is not confirmed until after surgical resection. Herein, we report a case of proliferative myositis of the right brachioradialis in a 64-year-old man. The patient presented with a rapidly growing, painless mass in his right forearm. Magnetic resonance imaging and fine-needle aspiration biopsy led to a diagnosis of proliferative myositis. Complete surgical resection of the mass was performed. Postoperative pathological examination confirmed the diagnosis. To the best of our knowledge, this is the first report of proliferative myositis in the right brachioradialis. Fine-needle biopsy is helpful in the diagnosis of proliferative myositis, thus avoiding unnecessary surgical trauma and costs.

Benign proliferative myositis of the sternohyoid muscle: review and case report

We report a case of a 51-year-old woman who presented with a rapidly enlarging, painful, midline neck mass that developed over a three day period. A CT scan of the neck showed a solid circumscribed mass in the sternohyoid muscle. The initial differential diagnosis included inflammation of thyroglossal duct remnant, an abnormal lymph node, and thyroid carcinoma. The patient underwent operative excision with final pathology revealing proliferative myositis. Proliferative myositis is an uncommon benign proliferation of skeletal muscle and has only been reported a limited number of times in the head and neck region.

WITHDRAWN: Polymyositis of bilateral upper legs seen on FDG-PET/CT in a patient with rheumatoid arthritis

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Atypical proliferative myositis: original MR description with pathologic correlation: case report

Proliferative myositis (PM) along with proliferative fasciitis and nodular fasciitis are a group of pseudosarcomatous myofibroblastic proliferations. Although the histologic presentation of each is almost identical, the magnetic resonance imaging (MRI) appearance of proliferative myositis is closer to that of inflammatory myopathies. We report a case of PM in which the imaging and histologic features combine typical findings of PM with unusual imaging features, suggesting of reactive (or nodular) fasciitis.

A Patient with Psoriatic Arthritis Imaged with FDG-PET/CT Demonstrated an Unusual Imaging Pattern with Muscle and Fascia Involvement: A Case Report

We describe the case of a patient with known history of psoriasis that presented with 1 year of unexplained fever, muscle weakness and marked weight loss, suspicious for B symptoms of a malignant origin. [(18)F]-Fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) scans demonstrated an unusual serpiginous pattern of uptake in the fascia and muscles as well as lymph node activity. Multiple histological samples, including a final PET-probe guided lymph node surgical resection, excluded malignancy and confirmed the diagnosis of reactive inflammatory changes, with a plausible diagnosis of autoimmune lymphoproliferative syndrome with associated lymphadenitis, fasciitis and myositis, possibly mediated by tumor necrosis factor (TNF) inhibitor. To our knowledge, there is no evidence of a previously reported FDG uptake pattern of fascia and muscle involvement in psoriatic arthritis.

Proliferative myositis: expanding the differential diagnosis of a soft tissue mass in infancy

Proliferative myositis, a pseudosarcomatous lesion of skeletal muscle, is quite rare in the pediatric population. While benign, it is not always recognized as such, and may be treated with an extensive resection that can result in permanent disfigurement. We report a case of an infant with the diagnosis of proliferative myositis, who to our knowledge is the youngest patient to be evaluated with magnetic resonance imaging (MRI). Although the MRI findings are non-specific, we highlight the importance of considering proliferative myositis in the differential diagnosis of a soft tissue mass, which ultimately might prevent an overly aggressive resection in a child.

[Circumscript myositis ossificans in a four-year-old boy]

We present the case of a 4 year old boy with no previous personal or family history of interest, who attended the Paediatric Department of our hospital after a physical examination revealed a painful induration in the left arm which had increased in size; imaging tests were consistent with a calcified mass in soft tissues, without cortical involvement, suspected of being malignant. Two-phase bone scintigraphy was requested in which a soft tissue lesion, not suggestive of malignancy, was detected. The biopsy was negative for malignant cells. However, in view of the progressive increase in size of the lesion, FDG positron emission tomography (FDG-PET) was performed, showing a hypermetabolic mass consistent with malignancy in the left arm, for which the patient underwent surgery for suspected possible parosteal osteosarcoma.

Intraoral proliferative myositis: Case report and literature review

BACKGROUND

Proliferative myositis is a rare, benign, reactive intramuscular lesion of fibroblastic/myofibroblastic origin; an identical lesion in a subcutaneous or fascial location is referred to as proliferative fasciitis. The rapid growth rate and unusual histopathologic features have frequently been mistaken for a malignant process and have promoted unnecessary invasive procedures. Here we present only the third oral case of proliferative myositis, arising from the tongue of a 65-year-old man.

METHODS AND RESULTS

Histologically, the resected lesion was composed of numerous fibroblastic or myofibroblastic spindle cells and variable numbers of large ganglion-like cells infiltrating between and around muscle fascicles, resembling a "checkerboard" configuration. A demographic profile of proliferative myositis of the head and neck is also provided, compiled from 19 patients culled from an English-language literature review and this report.

CONCLUSIONS

Incisional biopsy or fine-needle aspiration biopsy of proliferative myositis of the head and neck should lead to spontaneous resolution and is, therefore, sufficient to render the diagnosis and to provide conservative treatment. Recurrence is extremely rare.

Multidetector CT of musculoskeletal disease in the pediatric patient: principles, techniques, and clinical applications

Computed tomography (CT) plays an important role in the evaluation of musculoskeletal disease in the pediatric patient. With the advent of high-performance 16-section multidetector CT, images can be produced with subsecond gantry rotation times and with submillimeter acquisition, which yields true isotropic high-resolution volume data sets; these features are not attainable with older spiral CT technology. Such capabilities are particularly helpful in the evaluation of pediatric patients by virtually eliminating the need for sedation and minimizing dependence on patient cooperation. The role of three-dimensional (3D) volume imaging in the evaluation of pediatric musculoskeletal disease continues to evolve, with this technique becoming increasingly important in detection and characterization of lesions as well as in decisions about patient care. Specific designs and protocols for multidetector CT studies can be selected to minimize radiation dose to the patient. Principal clinical applications of 3D CT in evaluation of the pediatric musculoskeletal system include developmental abnormalities, trauma, neoplasms, and postoperative imaging.

Proliferative myositis: value of imaging

Imaging findings in a 52-year-old woman with proven proliferative myositis are described. US revealed preservation of continuous muscle bundles and patchy areas of hyperechogenicity, containing hypoechoic lines. MRI showed at T2-w sequences an ill-defined, hyperintense, intramuscular lesion, containing isointense lines. Subtotal enhancement, a nonenhancing geometrical web, and fascial enhancement were noted. In patients with painful growing masses, US and MRI correlation may suggest the diagnosis of proliferative myositis leading to biopsy, thus avoiding mutilating surgery.

Magnetic resonance imaging of congenital, inflammatory, and infectious soft-tissue lesions in children

Magnetic resonance imaging has the advantages of multiplanar capability and high degree of tissue differentiation. It is useful for assessing the extent of soft-tissue abnormalities, such as vascular malformations, inflammatory and infectious processes, muscle disorders, and limb hypertrophy. Magnetic resonance imaging is sensitive to the presence of water and edema and is a good indicator for early diagnosis of inflammation and its level of activity. Fat-saturation techniques, including T2-weighted sequences and inversion recovery imaging, optimize diagnostic accuracy. T1-weighted images are good at defining the distribution and proportion of fat in the body, so they are useful in evaluating syndromes of the limbs, including vascular malformations, as well as lipoatrophy-lipodystrophy conditions. Magnetic resonance imaging provides guidance for efficient tissue biopsy. It allows comprehensive pretherapeutic assessment of soft-tissue vascular anomalies. It constitutes a good modality for following up the natural history of soft-tissue disorders during childhood.