Age / Sex : 65 / F

Elastofibroma dorsi

Discussion

Findings: There are about 3.4 cm x
8.1 cm (Right) and 6.5 cm x 2.5 cm (Left) sized masses in the infrascapular
region of both back. They are located deep to serratus anterior and latissimus
dorsi muscles. Masses show iso signal intensity on both T1WI and T2WI, and mild
heterogeneous contrast enhancement.

 

Differential Diagnosis: Liposarcoma

Diagnosis:
Elastofibroma dorsi

Discussion:
Elastofibroma dorsi is a benign
soft-tissue tumor composed of fibrous tissue with internal fatty streaks. Elastofibroma
dorsi is classically found in the infrascapular regions, deep to the serratus
anterior and latissimus dorsi muscle. Unilateral masses have a slight
right-sided predilection, but up to 60% of elastofibromas are bilateral. The CT
image shows a poorly defined soft tissue mass in the infrascapular or
subscapular region with attenuation similar to that of the adjacent muscle. On
MRI, elastofibromas demonstrate alternating fibrous and fatty tissue. The mass
is isointense to muscle (fibrous tissue) with linear or curvilinear fat signal
intensity. Contrast-enhanced MRI shows heterogeneous enhancement. On FDG-PET/CT,
mild and moderate uptake is frequently observed in elastofibroma dorsi, which
should not be misinterpreted as malignant lesions.

References:

1. Ochsner JE, Sewall SA, Brooks GN et-al. Best cases from the
AFIP: Elastofibroma dorsi. Radiographics. 26 (6): 1873-6

2. Naylor MF, Nascimento AG, Sherrick
AD et-al. Elastofibroma dorsi: radiologic findings in 12 patients. AJR Am J
Roentgenol. 1996;167 (3): 683-7.

3. Onishi Y, Kitajima K, Senda M et-al. FDG-PET/CT imaging of
elastofibroma dorsi. Skeletal Radiol. 2011;40 (7): 849-53.