H. Rössler (Universität Leipzig)  

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16 Years  

Male  

Leg-Muscular system / Connective tissue / Skin  

unknown  

Patient History: Acute pain on use in the left thigh. First admittance to our clinic was about 4 weeks ago. At time of presentation, the symptoms were already regressing. No known trauma.
Local findings: Pain on pressure of the left thigh. No redness, no palpable resistance and no swelling.
Lab: Inflammatory constellation (CRP 23 mg/l, BSR 42/82, Leukocytes 12 Gpt/l, Hb/Hk/Thrombocytes in normal range).  

There are three theories of the development of this disease:
1. Organized hematomas
2. Chipping of the periost and osteoblast wandering across periostal gaps
3. Connective tissue metaplasia.

One differentiates between the different forms as, i.e. Traumatic m.o., atraumatic m.o. and neuropathic m.o.  

<- view X-Ray 1

X-Ray 1: Conventionally, one finds a circular calcified structure in the soft tissues.




<- view Ultrasound 1

Ultrasound 1: The calcified structures are seen in ultrasound as shadow-radiating lesions.



<- view Ultrasound 2

Ultrasound 2: The surrounding musculature is increased in echoes.



<- view MRI 1

MRI 1: T2 STIR: Representation of a bound, inhomogenically hyperintense RF in the soft tissues of the left thigh.




<- view MRI 2

MRI 2: In the T1-weighted image, the lesion is isointense with the muscle.




<- view MRI 3

MRI 3: T1 with fat saturation: Proof of a noticeable contrast media enhancement.




<- view MRI 4

MRI 4: T1 with fat saturation after administration of contrast media in the transversal slice through the lesion.


 

Surgery / Histo  

Rhabdomyosarcoma (MRI)
Osteosarcoma (X-Ray)
Progressive myositis ossificans as it's own illness.  

This is a benign process. It's course is phasic. In the early phases, proliferative fibroblasts cause a connective-tissue-like swelling of the tissue, which is followed by the intermediate phase (after 2 to 4 weeks) of development of an immature osteoid. In the late phase (after 6 to 24 months), mature lamellar bone is formed. The ossification is centripedal (in contrast to the ossification in osteosarcomas). Typically, a regression of the symptoms is seen in the course of disease. At the end, a spontaneous resorption or the incomplete regression can occur. Surgical intervention is only recommended if joints or nerves are involved, and when the lesion is mature.  

N/A  

The disease was named by Dusch in 1868.
The term "myositis ossificans" is not correctly chosen, since it is not for certain an inflammatory process, nor is the inflammatory process limited to the musculature.
According to the definition, myositis ossificans includes all non-neoplastic, extraossic bone development in a location which is not meant to be.  

1. Medline:
Mandar A Pattekar, MD
Myositis Ossificans
www.emedicine.com/ped/topic1538

2. Medline:
Henry DeGroot, MD
Myositis Ossificans
http://bonetumor.org/tumors/pages/page177.html

 

Circumscript myositis ossificans, heterotopic / ectopic ossification, Myositis Ossificans Circumscripta, Muscle pain, child, childhood, pediatric radiology  

H Rössler. Myositis Ossificans Circumscripta. PedRad [serial online] vol 4, no. 6.
URL: www.PedRad.info/?search=20040607115925