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

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

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

The diagnosis of soft tissue osteochondroma should be considered when a well-defined osseous mass is located in the soft tissues. The differential diagnosis includes myositis ossificans, tumoral calcinosis, synovial chondromatosis, and soft tissue osteosarcoma, true osteochondroma which arises from bone. One case of soft tissue osteochondroma in the knee, a lesion of uncertain pathogenesis is reported.
Calcinosis ; Chondromatosis, Synovial ; Diagnosis ; Diagnosis, Differential ; Knee ; Myositis Ossificans ; Osteochondroma* ; Osteosarcoma

Child, Preschool ; Diagnosis, Differential ; Humans ; Male ; Myositis Ossificans ; diagnosis ; diagnostic imaging ; pathology ; physiopathology ; Prognosis ; Tomography, X-Ray Computed

Eighty primary Harris-Galante Porus (HGP) total hip replacements were performed at Severance Hospital from January 1986 to January 1989. A minimum of 18 months follow-up was available for 80 hips in 72 patients, whose mean age was fifty two years. The most common presenting diagnosis was avascular necrosis (47.5%) followed by fused hips (10%), tuberculosis (10%), rheumatoid arthritis (7.5%). Complications included three calcar cracks and two immediate dislocations and 6 cases of mild myositis ossificans. There were no infections and no revisions. The mean Harris hip score was 93 points (range, 74–100 points) at two years. The thigh pain was in nine patients (11 per cent) at one year and in three patients (3 per cent) at two years postoperatively. Radiographic analysis revealed that, a progressive radiodense femoral line developed in 21 hips (26 per cent); a progressive acetabular line in 3 hips (4 per cent); and decreased proximal femoral density in 28 hips (35 per cent). There were no position change of the acetabula and femoral compent. We conclude that the early overall clinical results of HGP total hip replacements are encouraging, at average 30 months. The prognostic significance of the radiographic changes such ar radiodense lines, the changes of the proximal femur and cortical thickening, have to be determined with longer follow-up. Long term follow-up of uncemented HGP total hip replacement is necessary to evaluate the efficacy of such implants.
Acetabulum ; Arthritis, Rheumatoid ; Arthroplasty, Replacement, Hip ; Diagnosis ; Dislocations ; Femur ; Follow-Up Studies ; Hip ; Humans ; Myositis Ossificans ; Necrosis ; Thigh ; Tuberculosis

Fibrodysplasia ossificans progressiva (FOP) is a rare connective tissue disorder characterized by congenital malformation of the great toes and by progressive heterotopic ossification of the tendons, ligaments, fasciae and skeletal muscles. We document the radiologic manifestation of FOP passed from a sporadically affected father to each of his two children (a son and a daughter). Previous consideration of a genetic etiology was based on the fact that the disease has been reported in several sets of monozygotic twins and that increased paternal age has been associated with sporadic occurrence of the disorder. Although autosomal-dominant transmission has long been suspected, the findings in this family provide confirmation for such inheritance and a basis for the diagnosis and counseling of patients with FOP.
Child ; Connective Tissue ; Counseling ; Diagnosis ; Fascia ; Fathers ; Humans ; Ligaments ; Muscle, Skeletal ; Myositis ; Myositis Ossificans* ; Ossification, Heterotopic ; Paternal Age ; Tendons ; Toes ; Twins, Monozygotic ; Wills

The aspiration cytologic finding of myositis ossificans is not well documented but similar to that seen in nodular fasciitis except less cellularity. Myositis ossificans is a reactive condition that is sometimes mistaken microscopically for extraosseous osteosarcoma. Cytologically, myositis ossificans may be distinguished from extraosseous osteosarcoma by the presence of uniform benign stromal cells composed of mature fibroblasts and osteoclastic giant cells. However, the differential diagnosis may be difficult in the early stage of this reactive and proliferative process. We recently experienced a case of myositis ossificans. The patient was a 67-year-old woman with painful swelling of the left index finger for one month. Simple x-ray finding showed a soft tissue mass with calcific center at middle phalanx of the left hand. Fine needle aspiration cytology revealed a few individual or clusters of spindle cells in dense eosinophilic stroma with osteoclastic giant cells. The spindle cells were uniform, smooth-bordered, and oval nuclei with single small inconspicuous nucleoli, and elongated cytoplasm. The scattered individual cells had eccentric nuclei with one or two nucleoli and abundant, basophilic cytoplasm.
Aged ; Basophils ; Biopsy, Fine-Needle* ; Cytoplasm ; Diagnosis, Differential ; Eosinophils ; Fasciitis ; Female ; Fibroblasts ; Fingers ; Giant Cells ; Hand ; Humans ; Myositis Ossificans* ; Myositis* ; Osteoclasts ; Osteosarcoma ; Stromal Cells

Fibrodysplasia ossificans progressive (FOP) is an extremely rare disabling disorder characterized by progressive heterotopic ossification associated with congenital digital malformations. The purpose of this study is to delineate the problems in diagnosis and treatment of this rare disease, and to present their solutions. Nine Korean FOP patients have been followed up for average 7.2 years. Their medical records and radiographs were reviewed, and they were reexamined directly or interviewed by telephone. There were 6 female and 3 male patients. The age at the time of this study averaged 13.3 years (range, 4 to 23). In 5 cases, the first clinical manifestation was migrating scalp and neck mass at the age of 1-2 years. The diagnosis was delayed for 3 year and 5 months at average although all the patients had pathognomonic big toe anomaly. Surgical excision of heterotopic ossification in an attempt to increase the joint motion was performed in 4 cases but in vain. Posterior spinal fusion in 1 case failed to prevent progression of scoliosis and trunk decompensation. Disodium etidronate, tried in 3 patients, brought no effective symptom relief. All the patients in their 20's were household ambulators. Understanding the clinical manifestation of this disease enables early diagnosis, by which unnecessary and harmful procedures such as surgical biopsy or excision can be avoided, although no effective treatment has been developed.
Biopsy ; Diagnosis ; Early Diagnosis ; Etidronic Acid ; Family Characteristics ; Female ; Humans ; Joints ; Male ; Medical Records ; Myositis Ossificans* ; Neck ; Ossification, Heterotopic ; Rare Diseases ; Scalp ; Scoliosis ; Spinal Fusion ; Telephone ; Toes

OBJECTIVETo study the clinicopathologic features, diagnosis and differential diagnosis of myositis ossificans (MO).

METHODSThe clinical features, radiologic results and pathologic findings of 15 cases of MO (including biopsy and surgical specimens) were analyzed. The hematoxylin and eosin sections were reviewed under light microscope. Immunohistochemical staining for S-100 protein, vimentin, desmin, actin and osteonectin was performed.

RESULTSThe age of the patients ranged from 12 to 46 years. The male-to-female ratio was 11:4. Thirteen cases were located in the parosteum of long bone or subperiosteal soft tissue. The remaining two cases occurred in iliac region and palm, respectively. Five patients had history of injury, while 2 patients had operation before. Four patients had no history of trauma and the remaining one had unknown clinical history. Histologically, zonation pattern was not conspicuous in 10 biopsy cases and 8 corresponding surgical specimens. On the other hand, zonation pattern was observed in 5 biopsy cases and 7 corresponding surgical specimens. Follow up revealed relapses in two patients. Immunohistochemical study showed various degree of positivity for vimentin, desmin, actin and osteonectin. S-100 protein was focally positive in 2 of the cases. The Ki-67 index varied from 1% to 10%.

CONCLUSIONCorrect diagnosis of MO relies on correlation of clinical features, radiologic examination and pathologic findings.

Adolescent ; Adult ; Biopsy ; Child ; Female ; Humans ; Male ; Middle Aged ; Myositis Ossificans ; diagnosis ; genetics ; pathology ; S100 Proteins ; genetics ; Vimentin ; X-Rays ; Young Adult