AJR 2004; 182:1090-1091
© American Roentgen Ray Society
Foreign-Body Granuloma Caused by Dispersed Oil Droplets Simulating Subcutaneous Fat Tissue on MR Images
Sang Yong Lee,
Nae Ho Lee,
Myong Ja Chung and
Gyung Ho Chung
Chonbuk National University Hospital Chonju, Chonbuk 561-172,
Korea
A 28-year-old man presented with a 2-month history of a palpable mass in
the dorsum of the right wrist. His medical history included contusion and a
1-cm laceration on the palmar aspect of the right hand that resulted from an
explosion of hydraulic equipment 5 months earlier. At that time, he had
undergone débridement of the palm and interdigital web spaces of the
right hand because of cellulitis caused by the laceration and by foreign
bodies such as oil, splinters of rubber, and wire. Physical examination showed
that the mass was approximately 3 cm in diameter and was soft, relatively
fixed, and nontender.
On sonography, the mass appeared elliptic and was located in the
subcutaneous fat layer of the dorsum of the right wrist. It showed
heterogeneous echogenicity with an ill-defined hypoechogenic rim
(Fig. 5A). MRI detected the
mass shown on sonography and also revealed abnormal clusters of small round
variable-sized well-circumscribed lesions scattered on both palmar and dorsal
aspects of the hand and wrist. The clustering lesions had high signal
intensity on T1-weighted images and low signal intensity with peripheral
enhancement after IV administration of contrast medium (Figs.
5B and
5C).
View larger version (121K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5A. —28-year-old man who presented with palpable mass in dorsum of
wrist. Longitudinal sonogram shows heterogeneous echogenic soft-tissue mass
(arrows) with partial acoustic enhancement adjacent to extensor
tendon (arrowheads).
|
|
View larger version (118K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5B. —28-year-old man who presented with palpable mass in dorsum of
wrist. Sagittal spin-echo T1-weighted MR image of wrist shows foreign-body
granuloma (long arrow) with mild peripheral high-signal-intensity rim
(short arrows) and high-signal-intensity oil droplets
(arrowheads) in dorsal and palmar soft tissue.
|
|
View larger version (105K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5C. —28-year-old man who presented with palpable mass in dorsum of
wrist. Sagittal fat-suppressed contrast-enhanced T1-weighted MR image shows
peripheral enhancing rim of foreign-body granuloma (arrow) and
low-signal-intensity oil droplets surrounded by enhancing rim
(arrowheads).
|
|
The wrist mass was surgically removed. Grossly, the grayish solid mass was
dotted with small, cystlike structures and showed central necrosis
(Fig. 5D). The history of
trauma by hydraulic equipment in conjunction with the radiographic and
histologic findings supported the diagnosis of foreign-body granuloma by oil
droplets.
View larger version (121K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5D. —28-year-old man who presented with palpable mass in dorsum of
wrist. Photomicrograph of gross specimen of foreign-body granuloma shows
transparent scattered oil droplets (arrowheads).
|
|
To our knowledge, the radiologic finding of foreign-body granuloma caused
by dispersed oil droplets with high signal intensity on T1-weighted MR images
has not been previously reported in the English-language literature. MRI has
been used for the detection and localization of nonmetallic foreign bodies and
for the evaluation of soft-tissue masses caused by long-standing foreign
bodies [1,
2]. Monu et al.
[1] detected and localized a
foreign body associated with soft-tissue granuloma in the forefoot. Most
radiologists expect the signal intensity of foreign bodies to be low because
common foreign bodies presenting clinically are materials such as metal, wood
slivers, pencil fragments, and glass with few mobile protons. However, in this
case, the signal intensity of oil foreign bodies was high on T1-weighted MR
images. The wide distribution of the oil droplets could be detected on
fat-suppressed T1-weighted MR images after contrast administration because of
the low signal intensity of the oil droplets and their peripheral enhancement.
Foreign-body granuloma caused by high-signal-intensity bodies on T1-weighted
MR images might be included in the differential diagnosis of soft-tissue
masses of an extremity.
References
- Monu JU, McManus CM, Ward WG, Haygood TM, Pope TL Jr, Bohrer SP.
Soft-tissue masses caused by long-standing foreign bodies in the extremities:
MR imaging findings. AJR1995; 165:395
–397[Free Full Text]
- Varma DG, Ro JY, Guo SQ, Moulopoulos LA. Magnetic resonance imaging
appearance of foreign-body granulomas of the upper arms. Clin
Imaging 1994;18:39
–42[Medline]
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
