대한근골격영상의학회

Title : Case 546

Age / Sex : 73 / F Chief complaint: Thigh mass What is your impression? Two weeks later, you can see the final diagnosis with a brief discussion of this case. (Please submit only one answer) Courtesy: Hee Jin Park, Kangbuk Samsung hospital Discussion Findings: Encapsulated ovoid mass T1 iso SI and T2 heterogenous high SI with internal hemorrhage In the vastus lateralis muscle or intermuscular space widening of intermuscular space between Rectus femoris and vastus intermedius muscle Peritumoral ill-defined T2 hyperintense lesion -- extended to intermuscular space of rectus femoris and vastus intermedius muscle Differential Diagnosis: 1) Benign neurogenic tumor such as schwannoma 2) Malignant neurogenic tumor 3) Undifferentiated pleomorphic sarcoma Diagnosis: Undifferentiated pleomorphic sarcoma (UPS) Discussion: Histologically they are very heterogeneous in appearance and cellularity, but they all contain pleomorphic cells Some forms have abundant giant cells or a diffuse inflammatory component (giant cell/inflammatory UPS) Refer to Fig. provided above. Treatment and prognosis Most are of high grade (3 and 4) and are aggressive in their biological behavior Frequently metastasis (30-50% at diagnosis) and locally recur despite aggressive treatment The overall 5 year survival : 25-70% MRI Modality of choice for assessing soft tissue sarcomas Typically relatively well circumscribed, located within or adjacent to muscle, exerting positive mass effect on surrounding structures due to their (usual) large size at presentation T1: intermediate (to low) SI, similar to adjacent muscle heterogeneity if haemorrhage, calcification, necrosis, myxoid material present prominent enhancement of solid components, especially in tumor periphery due to central location of hemorrhage, necrosis and myxoid component. T2: intermediate to high SI heterogeneity if haemorrhage, calcification, necrosis, myxoid material present References: 1. Eur Radiol (2009) 19: 1499–1511

Title : Case 546

Age / Sex : 73 / F

Chief complaint: Thigh mass

What is your impression?
Two weeks later, you can see the final diagnosis with a brief discussion of this case. (Please submit only one answer)

Courtesy: Hee Jin Park, Kangbuk Samsung hospital

Discussion

Findings:

Encapsulated ovoid mass

T1 iso SI and T2 heterogenous high SI with internal hemorrhage In the vastus lateralis muscle or intermuscular space

widening of intermuscular space between Rectus femoris and vastus intermedius muscle

Peritumoral ill-defined T2 hyperintense lesion

-- extended to intermuscular space of rectus femoris and vastus intermedius muscle

Differential Diagnosis:

1) Benign neurogenic tumor such as schwannoma

2) Malignant neurogenic tumor

3) Undifferentiated pleomorphic sarcoma

Diagnosis:

Undifferentiated pleomorphic sarcoma (UPS)

Discussion:

Histologically they are very heterogeneous in appearance and cellularity, but they all contain pleomorphic cells

Some forms have abundant giant cells or a diffuse inflammatory component (giant cell/inflammatory UPS)

Refer to Fig. provided above.

Treatment and prognosis

Most are of high grade (3 and 4) and are aggressive in their biological behavior

Frequently metastasis (30-50% at diagnosis) and locally recur despite aggressive treatment

The overall 5 year survival : 25-70%

MRI

Modality of choice for assessing soft tissue sarcomas

Typically relatively well circumscribed, located within or adjacent to muscle, exerting positive mass effect on surrounding structures due to their (usual) large size at presentation

T1: intermediate (to low) SI, similar to adjacent muscle

heterogeneity if haemorrhage, calcification, necrosis, myxoid material present

prominent enhancement of solid components, especially in tumor periphery due to central location of hemorrhage, necrosis and myxoid component.

T2: intermediate to high SI heterogeneity if haemorrhage, calcification, necrosis, myxoid material present

References:

1. Eur Radiol (2009) 19: 1499–1511