Alveolar soft part sarcoma: MR and angiographic findings.
OBJECTIVE
To present the MR and angiographic findings of alveolar soft part sarcoma (ASPS).


METHODS
MR examinations (12 tumors of 10 patients) of ASPS performed at multiple hospitals were retrospectively reviewed. The tumors were found in the thigh (n=4), lower leg (n=4), femur (n=2, local metastasis), scalp (n=1) and arm (n=1). The MR signal characteristics including signal intensity, homogeneity and signal void of lesions and bony invasion including direct invasion or local metastasis were evaluated. Angiographic findings (n=4) and post-embolotherapy follow-up MR imaging (n=2) findings were also assessed.


RESULTS
Local bony metastasis was found in two cases. Seven tumors showed heterogeneous high signal intensity on T - and T2-weighted images with good enhancement. One tumor had a very high signal on T1-weighted images. Eight tumors (67%) showed numerous signal voids in or near the tumors. All four angiographic studies showed numerous enlarged vessels, arteriovenous shunts and delayed washout. Two cases mimicked arteriovenous malformations on angiographic studies but MR images demonstrated solid soft tissue components as well as tortuous vessels.


CONCLUSIONS
High signal on T1 -weighted image and numerous signal voids are highly suggestive of ASPS, although they are not universal as has been suggested and arteriovenous malformation should be included in the differential diagnosis. Local bony metastases in ASPS were seen in two cases and should be carefully investigated.
Department of Diagnostic Radiology, College of Medicine Yonsei University, Seoul, Korea.
J S
JS
Suh
J
J
Cho
S H
SH
Lee
K H
KH
Shin
W I
WI
Yang
J H
JH
Lee
J H
JH
Cho
K J
KJ
Suh
Y J
YJ
Lee
K N
KN
Ryu
D000293:Adolescent; D000328:Adult; D000792:Angiography; D001132:Arm; D001859:Bone Neoplasms / Q000556:secondary; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007866:Leg; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018234:Sarcoma, Alveolar Soft Part / Q000175:diagnosis* / Q000556:secondary