It is also sometimes known as heterotopic ossification. Mar 26, 2020 myositis ossificans is an unusual condition in which bone starts growing inside the muscle. In three cases, and possibly four, ct scans obtained during the active stage of the pathologic process dem. Myositis ossificans is an extraosseous non neoplastic growth of new bone. Myositis ossificans circumscripta refers to posttraumatic calcification of soft tissue, including various ligaments. Robert j pignolo, pediatric fibrodysplasia ossificans progressiva myositis ossificans medscape emedicine, updated sept. In three cases, and possibly four, ct scans obtained during the active stage of the pathologic process demonstrated findings that in general corresponded to the zone phenomenon seen on histology, although a distinct peripheral ring. Dec 02, 2018 what is the prognosis of myositis ossificans circumscripta.
It is a documented side effect of the lipidlowering drugs statins and fibrates. However, myositis ossificans only occurs in 917% of muscle bruises. Bilateral and recurrent myositis ossificans in an athlete. Edema within surrounding muscles is typically present on t2weighted.
Myositis ossificans circumscripta pathology britannica. Progressive myositis ossificans is a rare, inherited disorder characterized by fibrosing and. Myositis ossificans is an unusual condition that causes bone to form deep within muscles of the body. Myositis ossificans an overview sciencedirect topics. Sustained at any level of play or competition, myositis ossificans is the formation of bone tissue inside muscle tissue after a traumatic injury to the area. Myositis ossificans mo is a nonneoplastic, selflimiting, heterotopic bone formation occurring typically in large muscles of the extremities. Aug 14, 2018 myositis ossificans is a misnomer, although the term myositis ossificans circumscripta continues to be used to describe nonhereditary forms of heterotopic. It may occur at any age, but is rare in infants or older patients. Diagnostic valueofarteriography issayaghmai myositis ossificans circumscripta istheheterotopic formation ofnonneoplastic boneandcartilage insofttissue. Myositis ossificans develops some time after a contusion or blow to a muscle usually in the thigh.
Myositis ossificans, disorder of unknown cause in which connective tissue and muscle are replaced by bone. Also myositis ossificans circumscripta is another synonym of myositis ossificans traumatica refers to the new extraosseous bone that appears after trauma. Mri of myositis ossificans circumscripta sciencedirect. Myositis ossificans traumatica of the thenar region n. In this condition, bone tissue forms within a muscle. Though the condition often accompanies bone trauma or complications, such as paralysis, it has also known to rarely present without injury or as an hereditary disorder. In the rare progressive type myositis ossificans progressiva, group after group of muscles become.
Pdf myositis ossificans circumscripta without history of trauma. Bone scintigraphy and 18ffluorodeoxyglucose positron emission tomographycomputed tomography miositis osificante. We believe that a hypertrophyoriented program without supervision of a. The diagnosis was myositis ossificans circumscripta. He was prescribed ibuprofen and started on a program of physical therapy. This case first appeared as performance improvement program in surgical. Skeletal muscle ossification was first reported as a complication of traumatic spinal paraplegia over a century ago. On the right at c45 is a well circumscribed heterogeneously calcifiedossified mass which measures 20 x 17 x 18 mm which appears to arise from and is continuous with the articular pillar, with involvement of the c45 facet joint which appears fused. These benign lesions can mimic more serious lesions, both radiographically and histopathologically. Myositis ossificans injuries thigh myositis ossificans what is myositis ossificans. Myositis is inflammation or swelling of the muscles.
Myositis ossificans mimicking sarcoma, the importance of. Through the possible diagnosis of myositis ossificans circumscripta moc, the patient underwent an excisional biopsy that confirmed the imaging diagnosis of moc in a patient without trauma history. Myositis ossificans circumscripta mo is an ossified soft tissue mass seen in. In early myositis ossificans, lesions are typically isointense to muscle on t1weighted images and heterogeneously hyperintense on t2weighted images. The term myositis ossificans traumatica is sometimes used when the condition is due to trauma. What is the prognosis of myositis ossificans circumscripta. Myositis ossificans heterotopic bone formation presents in two forms. Although extremely suggestive, the clinical features may be mistaken for those of a soft tissue tumor. Computed tomography was performed in five patients with myositis ossificans circumscripta. Although most cases of moc develop below the clavicles.
The imaging appearance of myositis ossificans varies in accordance with its stage of evolution. The circumscribed form is a benign, solitary, selflimiting disorder representing metaplasia of soft tissue to bone. It is usually as a result of impact which causes damage to the sheath that surrounds a bone periostium as well as to the. Learn more about myositis ossificans circumscripta from related diseases, pathways, genes and ptms with the novus bioinformatics tool.
Myositis ossificans mo occurs when bone or bonelike tissue grows where its not supposed to. This condition can be identified with the use of xray images which will reveal deposits of bone within the muscle and in locations where bone should. Myositis ossificans circumscripta moc is a pseudoinflammatory tumour originating from skeletal muscle and corresponds to an heterotopic, metaplastic, nonmalignant bone tumour. Early investigation by computed tomography ct usually establishes the correct diagnosis. Recognition of the benign character of myositis ossificans is imperative in order to avoid mutilating surgical procedures. Myositis ossificans is an uncommon condition that may occur following a thigh contusion bruised thigh and is characterized by bone formation calcification in the muscle belly at the site of the bruise. With adequate treatment, the prognosis is generally excellent. An unusual case of recurrent myositis ossificans mo bilaterally in the.
We describe an 11yearold boy with moc in his thigh. A history of local injury, most often related to trauma, was demonstrated in 3. It is usually confined to a single muscle or muscle group and is ubiquitous, predominantly located in. Myositis ossificans symptoms, causes and treatment. It most commonly happens in your muscle after an injury like when you get hit hard in the. A synonym for myositis ossificans is heterotopic ossification. Myositis ossificans circumscripta, overuse, soft tissue tumor, triceps. Features consistent with myositis ossificans circumscripta. Unsupervised exerciseinduced myositis ossificans in the. Tyler and asif saifuddin, journalseminars in musculoskeletal radiology, year2010, volume14 2, pages 20116. Often this condition is found in young athletes who sustain a traumatic injury, or sometimes as a result of repetitive injury to the muscle. Also known as myositis ossificans circumscripta, myositis ossificans traumatica, extraosseous localized nonneoplastic bone, myoosteosis, ossifying haematoma and traumatic ossifying myositis, 3 it is a localized, selflimiting, reparative lesion that is composed of reactive hypercellular fibrous tissue and bone. Myositis ossificans circumscripta moc is a benign condition with which many physicians are not familiar.
Myositis ossificans, mo, otherwise known as heterotopic ossification, is an extraosseous non neoplastic growth of new bone. The varying appearance of myositis ossificans relates to the histologic changes that occur as the disorder progresses. Myositis ossificans circumscripta is a form of heterotopic ossification that is benign in nature associated to a trauma, but may appear clinically and radiologically as a malignant neoplasm. Pdf myositis ossificans mo is an unusual pathological entity still largely unknown. There are several clinical subtypes of myositis ossificans. In these images, multiple echogenic foci arrows and distal shadows can be. Edema within surrounding muscles is typically present on t2weighted images.
Jul 25, 2017 myositis ossificans mo occurs when bone or bonelike tissue grows where its not supposed to. Myositis ossificans circumscripta of the sacrotuberous. We report an unusual case of myositis ossificans of the thenar muscles and discuss the diagnostic pitfalls whereby this condition can be mistaken. Myositis ossificans circumscripta moc is a localized, nonneoplastic, heterotopic ossification within the muscle. Juxtacortical myositis, a localized circumscribed type of myositis ossificans in close apposition to bone, was seen in 4 patients. It has also been referred to as traumatic myositis ossificans, myositis ossificans circumscripta. Myositis ossificans circumscripta moc, characterised by nonneoplastic heterotopic bone formation in soft tissue and skeletal muscle, is rare in children. Myositis ossificans definition of myositis ossificans by. At onset, it is difficult to distinguish moc from a musculoskeletal infection or neoplasm, particularly in absence of trauma, and a biopsy is frequently required. Myositis ossificans is one of the skeletal dont touch lesions.
Myositis ossificans circumscripta of the knee improved by. Two cases are presented in which magnetic resonance imaging mri clearly demonstrates disproportion ally extensive abnormal signal intensity along the course of muscle fibers. The difficulties of diagnosing myositis ossificans. Myositis ossificans is an uncommon condition that may occur following a thigh contusion bruised thigh and is characterized by bone formation calcification in the muscle belly at the site of the bruise the large muscle group at the front of your thigh is called the quadriceps figure 1. Localized areas of active myositis ossificans, occurring without a clear history of antecedent trauma, have been referred to as a pseudomalignant osseous tumor of soft tissue. Imaging studies include an ultrasound demonstrating a hyperechoic shell with a. The aim of this article is to report the imaging characteristics of mo, the emphasis being on the early diagnostic clues. It most commonly happens in your muscle after an injury like when you get hit hard in the thigh during a soccer game or maybe after a car or bicycle accident. Recognition of thebenign character ofmyositis ossificans isimperative.
Pdf circumscribed myositis ossificans of the masseter muscle. Myositis ossificans is a benign, metaplasmatic, mostly selflimiting process in which bone or bonelike tissue formation takes place in skeletal muscle. Myositis ossificans is a condition stemming from an injury that can occur in many types of sports. These imaging findings were suspicion of myositis ossificans and mri was rejected because has limited its role in the calcifications. Fdg petct findings in a case of myositis ossificans circumscripta of the forearm. When a bruise contusion, repetitive trauma, or strain occurs to a muscle, myositis ossificans can develop. Oct 11, 2016 myositis ossificans can occur as a complication of not treating a contusion correctly. Its importance stems in large part from its ability to mimic more aggressive pathological processes. Marchiori, in clinical imaging third edition, 2014. This is a rare benign ossifying lesion in skeletal muscles, mostly caused by a trauma and with an average age of occurrence between 20 and 30. It involves a small growth of bone within the muscle and usually occurs a while after the original injury.
The oldest imaging available for comparison, the mri from 2011, suggests a fracture fragment at the c5 superior articular process, with no mr evidence of fusion across the c45 facet at that time. Mo circumscripta, limited to a single muscle and generally. In these patients, ct was useful in limiting the differential diagnosis and obviating surgery. Knowledge of the mr appearance of myositis ossificans is important in that the lesion has many of the mr imaging characteristics frequently associated with malignancy. Myositis ossificans circumscripta definition of myositis. If you have a bad muscle strain or contusion dead leg. In its active phase, the arteriographic findings in myositis ossificans circumscripta will consist of hypervascularity.
Myositis ossificans circumscripta or pseudomalignant osseous tumor of soft tissue may be confused with malignant neoplasms if there is no clear history of trauma. The criteria for a malignant lesion, however, will be absentarteriovenous sh. In the more common local type myositis ossificans circumscripta, only one area is affected. Diagnosis of myositis johns hopkins myositis center. Ho that occurs in muscle is also known as myositis ossificans. Traumatic myositis ossificans circumscripta moc bmj. Adapted from the teaching files of the department of radiology and imaging at hospital for special surgery. Myositis ossificans traumatica of the medial pterygoid muscle. Mr imaging features, particularly after injection of gadopentetate dimeglumine, mimicked those of an inflammatory mass or neoplasm. Magnetic resonance imaging mri can be helpful in doubtful cases. The angiographic appearance of myositis ossificans circumscripta.
In three cases, and possibly four, ct scans obtained during the active stage of the pathologic process demonstrated. Heterotopic ossification heterotopic ossification ho is a process by which the soft tissues around the hip become ossified. Myositis ossificans mo is a benign process characterized by heterotopic ossification usually within large muscles. Myositis ossificans circumscripta moc is an uncommon disease that has been reported to develop after trauma, burns, and infections, as well as in cases in which the pathogenesis is unknown. In order to make a definite diagnosis of myositis, the following criteria must be met. Hereditary mo includes fibrodysplasia ossificans progressiva and progressive osseous. The imaging features of the myositis ossificans will also be described in this article to avoid misdiagnosis or unnecessary biopsy or excision of this dont touch lesion.
Fibrodysplasia ossificans progressiva fop, or munchmeyer. These benign lesions canmimicmoreserious lesions, both radiographically andhistopathologically. Two cases are presented in which magnetic resonance imaging mri clearly demonstrates disproportionally extensive abnormal signal intensity along the course of muscle fibers. Patients should exhibit at least one of the following.
Myositis ossificans circumscripta refers to new extraosseous bone that. Myositis ossificans max superspecialty ortho clinic. Myositis ossificans mo is an inflammatory pseudotumor of the muscle that may be mistaken clinically and even histologically for a malignant soft tissue tumor. Myositis ossificans circumscripta refers to new extraosseous bone that appears after trauma. In the fifth patient, with longstanding myositis ossificans, ct showed complete ossification indicative of the mature phase of the pathologic process and was helpful in planning surgical resection. Around 60% to 75% of myositis ossificans cases occur as a result of trauma. It is most commonly found in muscle as a solitary lesion. However, posttraumatic calcification of ligaments in the pelvis is a rare complication described only anecdotally in the past. In the rare progressive type myositis ossificans progressiva, group after group of muscles become ossified, until the individual is completely rigid.
Gumprecht, the difficulties of diagnosing myositis ossificans circumscripta in the paraspinal muscles of a human immunodeficiency viruspositive man. In three cases, and possibly four, ct scans obtained during the active stage of the pathologic process demonstrated findings that in general corresponded to the zone phenomenon seen on histology, although a distinct peripheral ring of ossification was not always present. Ossifying softtissue lesions historically have been inconsistently classified. Despite advances in medical imaging, it remains difficult to distinguish it from. Myositis ossificans is a selflimiting, benign ossifying lesion that can affect any type of soft tissue, including subcutaneous fat, tendons, and nerves. Injury, medicines, infection, or an immune disorder can lead to myositis. Amendola ma, glazer gm, agha fp, francis ir, weatherbee l, martel w. Pediatric fibrodysplasia ossificans progressiva myositis. Myositis ossificans may sound like a complicated condition, but this abnormal bonetissue growth is a somewhat common sports injury.
The evolution of the focus of myositis ossificans can be correlated with the time lapse following trauma. Additional and relevant useful information for myositis ossificans circumscripta. Outcomesresolutions myositis ossificans circumscripta is a benign condition that occurs as a response to an injury. A short course of nonsteroidal antiinflammatory drug therapy may be an efficient treatment for early mo.
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