MRI and histological evaluation of the infiltrative growth pattern of myxofibrosarcoma.
OBJECTIVE
Myxofibrosarcoma often shows abnormal signal infiltration along the fascial plane on magnetic resonance imaging (MRI). The objective was to describe this MRI characteristic of myxofibrosarcoma with pathologic findings for comparison.


METHODS
Clinical, histological, and imaging data for 21 patients with myxofibrosarcoma were reviewed retrospectively.


RESULTS
Seventeen tumors showed a diffuse infiltrative pattern on MRI. All tumors with diffuse infiltrative growth pattern showed borderless extension of atypical cells with moderate nuclear atypia to the muscle fascia. Notably, the remaining four patients with focal growth pattern on MRI also demonstrated infiltrative growth pattern histologically suggesting that myxofibrosarcoma shows an infiltrative growth property even in the lack of infiltrative growth pattern on MRI.


CONCLUSIONS
Most myxofibrosarcoma show an infiltrative growth pattern histologically. Orthopedic oncologist should pay careful attention to accurately assess tumor extension. It seems prudent to resect the entire area of abnormal signal extension seen on MRI whenever possible to obtain an adequate surgical margin of myxofibrosarcoma.
Kaya
Mitsunori
M
Department of Orthopedic Surgery, Sapporo Medical University School of Medicine, S-1, W-16, Chuo-ku, Sapporo, 060-8543, Hokkaido, Japan. mkaya@sapmed.ac.jp
Wada
Takuro
T
Nagoya
Satoshi
S
Sasaki
Mikito
M
Matsumura
Tadaki
T
Yamaguchi
Takehiko
T
Hasegawa
Tadashi
T
Yamashita
Toshihiko
T
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005354:Fibrosarcoma / Q000175:diagnosis / Q000473:pathology* / Q000648:ultrastructure*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D012983:Soft Tissue Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000648:ultrastructure*