대한근골격영상의학회

Title : Case 129

Age / Sex : 35 / F Age / Sex : 35/F Chief complaint : RT.knee pain, duration : 1yr Trauma hx (-) 1) What is your impression? Two weeks later, you can see the final diagnosis with a brief discussion of this case. * Send Application Answers to Ja-Young Choi, MD (drchoi01@gmail.com) Courtesy: Kyu-Sung Kwack, MD., Ajou University Hospital Diagnosis: ossifying hemangioma Discussion Findings: Plain X-ray Ossified mass with Swiss cheese appearance posteromedial to the distal femur. MRI About 2x2cm in transverse dimension and about 4cm in longitudinal dimension mass lesion at distal thigh posteromedial aspect. The lesion is located in the deep to the semimembranosus muscle. The mass showed heterogenous intermediate signal intensity on T1WI, heterogenous high signal intensity on T2WI. The inner very low signal intensity on T1WI & T2WI corresponded to the irregular radiopaque densities on the plain radiographs. Enhanced sagittal T1WI shows heterogenous enhancement. Differential Diagnosis: 1. Myositis ossificans 2. Extraskeletal osteosarcoma 3. Synovial sarcoma Diagnosis: Intramuscular hemangioma with ossification Discussion: Only about 1% of hemangiomas originate in the skeletal muscle. Benign soft tissue tumors, predominantly involve the large muscles of the thigh. Highest prevalence in young women, in the 3^rd decade of life. Size : vary from less than 4cm to greater than 20cm, less than 9cm (m/c). Components : Vascular components, thrombus, calcifications, hemosiderin, fat, smooth muscle, and fibrous tissue, mature bone (extremely rare) Findings X-ray : Swiss cheese appearance, reflects architecture of mature bone interspersed with large cavernous vascular channels. MRI : intermediate signal intensity with a fairly well-delineated margin on T1WI and high signal intensity on T2WI. Heterogeneous signal intensity and a serpentine pattern. Contrast-enhanced MRI shows serpentine or latticelike enhancement of the lesions Low signal intensity on T1WI and T2WI can be caused byphleboliths, calcifications, ossification, or fibrosis. Although phleboliths in soft tissue hemangiomas are located within a thrombus of dilated vascular channels, ossification in soft tissue hemangiomas occurs within the fibrous stoma between the dilated vascular channels. The presence of phleboliths can be suggested when the low-intensity spot is located in enhanced vascular channels, and ossification can be diagnosed in the presence of an inner marrow signal. Additionally, the fibrotic change shows low signal intensity on T1WI and T2WI with mild enhancement. References: Intramuscular hemangioma with ossification, Ultrasound in Medicine • J Ultrasound Med 2008; 27:281–285

Title : Case 129

Age / Sex : 35 / F

Age / Sex : 35/F

Chief complaint : RT.knee pain, duration : 1yr

Trauma hx (-)

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

* Send Application Answers to Ja-Young Choi, MD (drchoi01@gmail.com)

Courtesy: Kyu-Sung Kwack, MD., Ajou University Hospital

Diagnosis:

ossifying hemangioma

Discussion

Findings:

Plain X-ray
Ossified mass with Swiss cheese appearance posteromedial to the distal femur.

MRI

About 2x2cm in transverse dimension and about 4cm in longitudinal dimension mass lesion at distal thigh posteromedial aspect. The lesion is located in the deep to the semimembranosus muscle. The mass showed heterogenous intermediate signal intensity on T1WI, heterogenous high signal intensity on T2WI. The inner very low signal intensity on T1WI & T2WI corresponded to the irregular radiopaque densities on the plain radiographs.

Enhanced sagittal T1WI shows heterogenous enhancement.

Differential Diagnosis:

1. Myositis ossificans

2. Extraskeletal osteosarcoma

3. Synovial sarcoma

Diagnosis: Intramuscular hemangioma with ossification

Discussion:

Only about 1% of hemangiomas originate in the skeletal muscle.

Benign soft tissue tumors, predominantly involve the large muscles of the thigh.

Highest prevalence in young women, in the 3^rd decade of life.

Size : vary from less than 4cm to greater than 20cm, less than 9cm (m/c).

Components : Vascular components, thrombus, calcifications, hemosiderin, fat, smooth muscle, and fibrous tissue, mature bone (extremely rare)

Findings

X-ray :

Swiss cheese appearance, reflects architecture of mature bone interspersed with large cavernous vascular channels.

MRI :

intermediate signal intensity with a fairly well-delineated margin on T1WI
             and high signal intensity on T2WI. Heterogeneous signal intensity and a
             serpentine pattern. Contrast-enhanced MRI shows serpentine or latticelike
             enhancement of the lesions

             Low signal intensity on T1WI and T2WI can be caused byphleboliths,
            calcifications, ossification, or fibrosis. Although phleboliths in soft tissue
            hemangiomas are located within a thrombus of dilated vascular channels,
            ossification in soft tissue hemangiomas occurs within the fibrous stoma
            between the dilated vascular channels. The presence of phleboliths can be
            suggested when the low-intensity spot is located in enhanced vascular
            channels, and ossification can be diagnosed in the presence of an inner
            marrow signal. Additionally, the fibrotic change shows low signal intensity
            on  T1WI and T2WI with mild enhancement.

References:

Intramuscular hemangioma with ossification, Ultrasound in Medicine • J Ultrasound Med 2008; 27:281–285